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Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), has a long association with maize (Zea mays mays L., Poaceae) and is among the crop's most significant pests worldwide. We contrasted the preference for and performance of FAW on three maize cultivars: the Mexican landrace Tuxpeño, the USA inbred B73 and B73‐lox10; B73‐lox10 is deficient in production of jasmonic acid (JA), green leaf volatiles (GLVs) and herbivore‐induced plant volatiles (HIPVs). Female oviposition and neonate colonization preferences were assessed in triple‐choice tests in greenhouse settings. Performance was assessed on the bases of larval, pupal and adult weights, larval and pupal development times, and adult longevity. We expected females to preferentially oviposit on plants on which their offspring performed best, and neonates to randomly colonize plants because they disperse aerially, presumably oriented solely by wind currents. Females preferred to oviposit on Tuxpeño plants, followed by B73‐lox10 and B73 plants, whereas their offspring performed best on B73‐lox10 and poorest on Tuxpeño. In contrast, neonates preferentially colonized plants on which they performed best, B73‐lox10, though initially and transiently they colonized plants on which they performed poorly, B73 and Tuxpeño. Altogether, our results showed that FAW females preferred to oviposit on maize plants on which their offspring's performance was poorest (Tuxpeño), and neonates preferentially colonized plants on which their own performance was best (B73‐lox10), though they initially colonized plants that were detrimental to their performance (Tuxpeño, B73). These results suggested that the ovipositional choices of FAW mothers are uncoupled from their offspring's performance, but newborn offspring rectified their mother's sub‐optimal host plant choice by colonizing plants that enhanced their own performance. Notably, these results also suggested that aerially dispersing (ballooning) FAW larvae do not colonize plants randomly, and that plant volatiles (GLVs, HIPVs) and JA may be relevant to host plant selection by ballooning larvae. [ABSTRACT FROM AUTHOR]

ABSTRACT The soldier crab, Mictyris guinotae, is a dominant intertidal crustacean associated with sand flats in the vicinity of the Urauchi River estuary on Iriomote Island, Japan. We compared various aspects of its reproductive biology at two sites (the river mouth and upper reach) on exposed bare sand flats 300 m and 3000 m upstream from the mouth. Bimonthly sampling was conducted between November 2010 and April 2011. The abundance of female crabs was higher at the mouth of the river. Female individuals had significantly larger body sizes (approximately 1.5 times larger carapace length) in the upper reaches. Despite the low presence of ovigerous females in the upper reach site, their larger body size led to the release of a substantial number of larvae per individual, although fewer larvae were produced per day than by females at the river mouth. The breeding period, as inferred from the occurrence of ovigerous females, persisted from December to March. At the upper reach site, the duration was slightly shorter, with an earlier peak. Variations in larval release timing may compensate for fluctuations in recruitment success. [ABSTRACT FROM AUTHOR]

Many marine species have a pelagic larval phase that undergo dispersal among habitats. Studies on marine larval dispersal have revealed a large variation in the spatial scale of dispersal and self‐recruitment. However, few studies have investigated the influence of types of coastline (e.g., bay vs. open coast) on marine larval dispersal. Bays or lagoons generally enhance the retention of larvae, while larvae are more likely to be flushed by strong currents in open coasts. To examine associations between larval dispersal, coastline type, and hydrodynamics, we compared fin‐scale dispersal patterns, self‐recruitment, and local retention (LR) of two anemonefishes (Amphiprion frenatus and Amphiprion perideraion) between a semi‐enclosed bay and an open coast in the Philippines combining genetic parentage analysis and biophysical dispersal modeling. Contrary to our expectations, parentage analysis revealed lower estimates of self‐recruitment in the semi‐closed bay (0%) than in the open coast (14–15%). The result was consistent with dispersal simulations predicting lower LR and self‐recruitment in the semi‐closed bay (0.4% and 19%) compared to the open coast (2.9% and 38%). Dispersal modeling also showed that cross‐shore currents toward offshore were much stronger around the semi‐closed bay and were negatively correlated with LR and self‐recruitment. These results suggest that stronger cross‐shore currents around the semi‐closed bay transport anemonefish larvae to the offshore and mainly contributed to the lower self‐recruitment. Our results highlight importance of hydrodynamics on larval dispersal and difficulty in predicting self‐recruitment from coastline type alone. [ABSTRACT FROM AUTHOR]

The black soldier fly (BSF), Hermetia illucens, has the ability to efficiently bioremediate organic waste into usable bio‐compounds. Understanding the impact of domestication and mass rearing on fitness and production traits is therefore important for sustainable production. This study aimed to assess patterns of genomic diversity and its association to phenotypic development across early generations of mass rearing under two selection strategies: selection for greater larval mass (SEL lines) and no direct artificial selection (NS lines). Genome‐wide single nucleotide polymorphism (SNP) data were generated using 2bRAD sequencing, while phenotypic traits relating to production and population fitness were measured. Declining patterns of genomic diversity were observed across three generations of captive breeding, with the lowest diversity recorded for the F3 generation of both selection lines, most likely due to founder effects. The SEL cohort displayed statistically significantly greater larval weight com the NS lines with pronounced genetic and phenotypic directional changes across generations. Furthermore, lower genetic and phenotypic diversity, particularly for fitness traits, were evident for SEL lines, illustrating the trade‐off between selecting for mass and the resulting decline in population fitness. SNP‐based heritability was significant for growth, but was low or non‐significant for fitness traits. Genotype–phenotype correlations were observed for traits, but individual locus effect sizes where small and very few of these loci demonstrated a signature for selection. Pronounced genetic drift, due to small effective population sizes, is likely overshadowing the impacts of selection on genomic diversity and consequently phenotypic development. The results hold particular relevance for genetic management and selective breeding for BSF in future. [ABSTRACT FROM AUTHOR]

Studies investigating gene flow in sessile or sedentary marine species typically draw conclusions about larval dispersal by investigating genetic structure of adults. Here, we generated microsatellite data from adults, recruits, settlers and planktonic larvae of the brown mussel, Perna perna, from the southeast coast of South Africa, and identified a consistent mismatch in genetic structure between the adults and all earlier life stages. While adults could be assigned to two major geographical groups (western and eastern), most of the early‐stage mussels were strongly affiliated with the eastern group. This suggests that few of the early‐stage individuals present in the western portion of the sampling range will eventually establish themselves in the adult population, highlighting the importance of post‐recruitment processes as drivers of population structure. Our findings caution against the exclusive use of genetic data generated from adults to assess population connectivity facilitated by the dispersal of planktonic propagules. [ABSTRACT FROM AUTHOR]

Simple Summary: The life cycle of marine benthic invertebrates includes a planktonic larval stage and a benthic adult stage, with larval settlement being the critical transition from a planktonic to a benthic lifestyle. Since adult mobility is limited or completely lost in the benthic environment, larval settlement directly affects population distribution, growth, and reproduction. Although larval settlement induced by natural chemical cues is widespread among marine invertebrates, the molecular mechanisms underlying this process remain unclear. Mytilopsis sallei, a typical marine fouling mussel, releases three purine compounds—adenosine, inosine, and hypoxanthine—that synergistically induce larval settlement. In this study, transcriptomic sequencing was employed to identify differentially expressed genes and signaling pathways associated with purine-compound-induced larval settlement. This research not only provides new insights into the molecular mechanisms of larval settlement in marine benthic invertebrates, but also offers a scientific basis and theoretical foundation for the ecological control of marine fouling organisms. The settlement of marine benthic invertebrate larvae is a crucial stage in their life cycle, directly influencing their population distribution, growth, and reproduction. It is generally believed that multiple chemical inducers in the environment synergistically affect larval settlement, though the underlying molecular mechanisms remain unclear. Our previous study has established that three purine compounds (adenosine, inosine, and hypoxanthine) released by adults of the mussel Mytilopsis sallei synergistically induced larval settlement. In this study, we performed transcriptomic sequencing analysis on larvae exposed to individual purine compounds and those exposed to a combination of three purine compounds. A total of 21,850 differentially expressed genes (DEGs) were identified. KEGG enrichment analysis of these DEGs revealed that the AMPK signaling pathway, FoxO signaling pathway, extracellular matrix (ECM)-receptor interaction, focal adhesion, and the thyroid hormone signaling pathway play key roles in the settlement of M. sallei larvae. Moreover, in larvae exposed to the combined action of three purines, the expression of relevant signaling pathways and metabolic processes was more significant. This research provides important information for understanding the molecular mechanisms underlying the induction of larval settlement in M. sallei by purine compounds in natural environments. [ABSTRACT FROM AUTHOR]

Simple Summary: The introduction of species into a new location is mediated by different factors, including the favorable conditions that the invasive species encounters in the host community. Among the non-native marine species well known for their potential as invasives, the azooxanthellate corals Tubastraea coccinea and Tubastraea tagusensis, introduced in the Caribbean Sea, the Gulf of Mexico and in the Brazilian Southwest Atlantic, stand out for their successful competition for space, multiple reproductive modes and high larval dispersal and recruitment. However, little is known about the feeding and trophic relationships of species of the genus Tubastraea, a gap that we sought to fill in the present study. Here, we show that invaded communities have a lower degree of trophic diversity, with species characterized by similar trophic ecologies. We also show that the invasive coral Tubastraea spp. occupies a trophic niche, similar to that of native species that are suspension feeders. Our results suggest that Tubastraea spp. is also a successful invasive species due to its superior competition for food. When a species is introduced in a new location, it is common for it to establish itself when it finds favorable conditions in the receptor community with regard to interspecific interactions with native species. The azooxanthellate corals Tubastraea coccinea and Tubastraea tagusensis are invasive species introduced in the Caribbean Sea, the Gulf of Mexico, and the Brazilian Southwest Atlantic. They are successful competitors for space, have multiple reproductive modes, and have high larval dispersion and recruitment, but studies on food and trophic relationships of the genus Tubastraea are still scarce. In the present study, we used isotopic values of δ13C and δ15N to investigate trophic relationships in rocky shore communities invaded by T. tagusensis and T. coccinea corals under different oceanographic and anthropogenic contexts. Using metrics derived from the isotopic values, we show that invaded communities have a lower degree of trophic diversity, with species characterized by similar trophic ecologies while abiotic factors seem to contribute to the biotic resistance of communities exposed to invasion events. Tubastraea spp. occupy a niche space similar to that occupied by the native community of suspension feeders, sharing resources already consumed by the receptor community, which makes invading corals successful competitors for food. [ABSTRACT FROM AUTHOR]

Nematodes are common in most terrestrial environments, where populations are often known to undergo cycles of boom and bust. Useful in such scenarios, nematodes present developmental programs of diapause, giving rise to stress-resistant larvae and enabling dispersal in search of new resources. Best studied in Caenorhabditis elegans , stress resistant dauer larvae emerge under adverse conditions, primarily starvation, and migrate to new niches where they can resume development and reproduce. Caenorhabditis elegans is a bacterivore but has been shown to harbor a persistent and characteristic gut microbiome. While much is known about the gut microbiome of reproducing C. elegans , what dauers harbor is yet unknown. This is of interest, as dauers are those that would enable transmission of microbes between nematode generations and geographical sites, maintaining continuity of host-microbe interactions. Using culture-dependent as well as sequencing-based approaches, we examined the gut microbiomes of dauers emerging following population growth on ten different natural-like microbially diverse environments as well as on two defined communities of known gut commensals and found that dauers were largely devoid of gut bacteria. These results suggest that host gut-microbiome interactions in C. elegans are not continuous across successive generations and may reduce the likelihood of long-term worm-microbe coevolution. [ABSTRACT FROM AUTHOR]

Fleas (Siphonaptera) are holometabolous insects with larval and adult stages that exhibit vastly different ecologies from each other. Adult fleas are parasitic and feed exclusively on the blood of a vertebrate host, whereas flea larvae do not live on hosts and consume dried faecal blood from adult fleas. Because flea larvae rely on adult flea faeces for food, excrement and eggs must fall in the same location; thus, larval density is likely high in these restricted habitats. However, the influence of larval density on the subsequent adult stage has not been examined. In the present study, we utilized egg density to investigate density‐dependent effects on larval development and adult body size in the cat flea (Ctenocephalides felis Bouché) (Siphonaptera: Pulicidae). Specifically, eggs were collected to create three different larval densities (n = 50, 100 and 150 per 56.7 cm2), and hatched larvae from all groups were fed an excess amount of adult faecal pellets. Larval development was measured by recording the proportion of eggs that developed to the pupal stage and the proportion of eggs that reached adulthood (eclosion). The body size of eclosed adults was quantified for both sexes using head length and length of the total body. We found that the number of eggs had no effect on the proportion of larvae that pupated or the proportion of larvae that eclosed; however, higher egg densities resulted in larger body sizes for both sexes. Overall, these data yield significant insight into how the ecology of larval fleas impacts the biology of the resultant adults. [ABSTRACT FROM AUTHOR]

Reproduction, embryological development, and settlement of corals are critical for survival of coral reefs through larval propagation. Yet, for many species of corals, a basic understanding of the early life‐history stages is lacking. In this study, we report our observations for ex situ reproduction in the massive reef‐building coral Porites cf. P. lobata across 2 years. Spawning occurred in April and May, on the first day after the full moon with at least 2 h of darkness between sunset and moonrise, on a rising tide. Only a small proportion of corals observed had mature gametes or spawned (14–35%). Eggs were 185–311 μm in diameter, spherical, homogenous, and provisioned with 95–155 algal cells (family Symbiodiniaceae). Males spawned before females, and ex situ fertilization rates were high for the first 2 h after egg release. Larvae were elliptical, ~300 μm long, and symbiotic. Just 2 days after fertilization, many larvae swam near the bottom of culture dishes and were competent to settle. Settlers began calcification 2 days after metamorphosis, and tentacles were developed 10 days after attachment. Our observations contrast with previous studies by suggesting an abbreviated pelagic larval period in Porites cf. P. lobata, which could lead to the isolation of some populations. The high thermal tolerance and broad geographic range of Porites cf. P. lobata suggest that this species could locally adapt to a wide range of environmental conditions, especially if larvae are locally retained. The results of this study can inform future work on reproduction, larval biology, dispersal, and recruitment in Porites cf. P. lobata, which could have an ecological advantage over less resilient coral species under future climate change. [ABSTRACT FROM AUTHOR]

Understanding genetic diversity and population connectivity in marine organisms is essential for fisheries management. In the present study, we examined the population genetics of the European squid, Loligo vulgaris, along the western Iberian Peninsula at two genetic resolutions using the mitochondrial cytochrome oxidase subunit I gene (COI) and genomic markers obtained via double digest restriction-site associated DNA sequencing (ddRADseq). The results obtained revealed 79 haplotypes out of 160 COI sequences, while the SNP data set included 86,431 loci after filtering for 38 individuals with 86,319 neutral data. Mitochondrial COI analyses revealed high haplotype (0.961) and nucleotide (0.010) diversities, and the haplotype network reveals complex sub-structure in Turkish waters within a panmictic population. Both Tajima's D and Fu's Fs tests suggest that the population of L. vulgaris analysed is evolving neutrally. Pairwise Fst for neutral SNPs were low (0 < Fst<0.002) and not significant showing high homogeneity among populations, while pairwise comparations for candidate adaptive SNPs (112 loci) showed Fst values ranging from 0.026 to 0.234. While neutral SNPs showed admixture, the candidate adaptive SNPs showed a moderate significant structure with a latitudinal discrimination. Overall, both genetic approaches showed homogeneity and strong genetic flux identifying a unique population along the Western Iberian Peninsula. [ABSTRACT FROM AUTHOR]

The recovery of isolated reef systems is a complex process that is usually associated with the supply of coral larvae from distant reefs (or large‐scale connectivity). However, a frequently neglected process is the potential for supply within the reef itself (or local connectivity). In this study, we quantify and characterize the role of local connectivity over 21 yr of simulated annual coral spawning on an isolated coral reef atoll using outputs from a high‐resolution biophysical model (< 150 m horizontal resolution) along with network analysis. We find that approximatively half of the coral reef larvae dispersal remains local (within 100 s m to 10 s km of release location), while the remaining half contributes to long‐distance dispersal (> 100 s km) and is exported away from the system. Local dispersal plays a pivotal role in creating a highly‐connected network across the reef, enhancing exchanges of larvae within the same reef patches (local retention), across reef zones (e.g., lagoon, reef flat), and across the larger reef system. Finally, we show that this highly‐connected network exhibits a certain level of robustness, even when exposed to environmental stressors such as thermal‐induced mortality. Our findings highlight the previously overlooked role of local scale dispersal in driving recovery of isolated reef systems and emphasize the importance of targeted local management actions, indicating that efforts directed at enhancing and preserving local connectivity can have a substantial impact on the overall health and resilience of isolated reef ecosystems. [ABSTRACT FROM AUTHOR]

Marine heatwaves (MHW) pose an increasing threat and have a critical impact on meroplanktonic organisms, because their larvae are highly sensitive to environmental stress and key for species' dispersion and population connectivity. This study assesses the effects of MHW on two key moulting cycle periods within first zoea of the valuable crab, Metacarcinus edwardsii. First, the changes in swimming behaviour during zoea I were recorded and associated to moult cycle substages. Then, larvae were exposed during the zoea I to (1) control temperature of 12 °C, (2) Early MHW, occurring in intermoult, (3) Late MHW, occurring in premoult and (4) 14 °C, representing MHW during whole development. Additionally, optimum temperature was estimated from thermal performance curves through swimming behaviour of one-day zoea I. The timing of the MHW within the moulting cycle significantly affects larval fitness. Early MHW led to improved survival rates (72%) and reduced developmental times (9.8 days) compared to those exposed to Later MHW (63% and 10.3 days, respectively). As optimum temperature was higher than 12 °C, MHW events maybe favouring larval performance. These results highlight the importance of interaction between the moult cycle and environmental variables as a factor of sublethal effects on population dynamics. [ABSTRACT FROM AUTHOR]

Fishing activities negatively impact fish populations, potentially causing a decline in fish stocks. Nevertheless, ensuring diversity and connectivity among populations can mitigate these adverse effects. To evaluate the connectivity of river mouths in the western part of Southern Java waters, we sequenced forty Stiphodon semoni individuals from five populations using mitochondrial cytochrome oxidase subunit 1 as molecular markers. The study revealed that S. semoni populations showed high diversity (0.821), with the population in Cimaja displaying the lowest diversity (0.464). Furthermore, the result of the analysis of molecular variance was a Fst value of 0.0630 with a p-value of 0.22. These results, along with the result of the haplotype network, indicated no significant genetic differences among these populations. This implies that the river mouths in the western part of Southern Java waters are interconnected. The distribution of mismatches showed a single peak, indicating that the populations have undergone demographic expansion. This information could be valuable for the conservation and management of S. semoni in the western part of the Southern Java waters. [ABSTRACT FROM AUTHOR]

Communication plays a fundamental role in the evolution of any form of cooperative behaviour, such as parental care. However, it can be challenging to understand the specific role of certain signals and how they might have evolved into complex communication systems. To investigate what effect a lack of acoustic communication can have on brood care and offspring performance, we silenced parents of biparentally caring burying beetles with a noninvasive method and studied the effect on clutch and offspring performance. Moreover, by analysing three species with varying degrees of offspring dependency on parental care, we aimed to investigate how differing acoustic communication is related to the level of their dependency and if those two align in some way. We used Nicrophorus pustulatus , a nondependent species, Nicrophorus orbicollis , a highly dependent species and Nicrophorus vespilloides , an intermediately dependent species. We found strong effects of silencing parents on offspring performance in all three species. The lack of stridulations impacted offspring weight across all three species. However, our results point towards a difference between species in which development stage communication had the most substantial impact. Looking at larval weight at dispersal, the effects seem to be in line with the larval dependency in the way we would have expected, with N. orbicollis being the most strongly affected, N. vespilloides being also affected and N. pustulatus not being affected. However, looking more closely, we found various differences at other time points and also that larval survival was strongly affected in N. pustulatus. Few studies have looked at the exact function of acoustic signals during brood care with most of them focusing on what type of different signals are emitted rather than what effect they have. Our study is one of the first to start disentangling the interplay of communication and offspring performance. • Silencing parents has a strong effect on offspring performance in burying beetles. • Different species of Nicrophorus differ in communication during brood care. • The larvae of silenced parents are at a disadvantage. • More dependent species do not, per se, rely more on communication. [ABSTRACT FROM AUTHOR]

Human‐transformed residuals, especially those derived from human waste (dumps), farmland, and livestock are involved in the emergence of antibiotic‐resistant bacteria (ARB) in the environment. Wildlife can act as vectors of ARB dispersal through different environments, but also as sentinels to detect the early spread and determine ARB sources. The development of integrated monitoring programmes focused on wildlife would help to anticipate the risks of ARB to humans and livestock.We used the yellow‐legged gull (Larus michahellis) as a model species to investigate and monitor the spatial patterns of ARB dispersal across an extensive farmland region located in northeastern Spain (Lleida). By integrating GPS tracking data and ARB clinical testing for 26 individuals within a network analysis framework, we modelled the risk of spatial pathogen spread through faeces during the bacteria‐transmission latency period (16 days after sample collection). Additionally, we created a connectivity network to determine the main sources of ARB in the area, focusing on three main habitats of special risk for infection: dumps, livestock facilities, and irrigation ponds.Seven individuals were infected by Escherichia coli, with one also co‐infected with Listeria monocytogenes and Salmonella spp. Potential pathogen dispersal distances ranged from 1.13 km to 23.13 km from the breeding colony. Our network analyses revealed 54 main nodes (i.e. high‐risk habitats recurrently visited by tracked gulls) and 1182 links among them. Our findings revealed a high degree of connectivity between the breeding area, located in a shallow lake, and nearby dumps, highlighting them as significant contributors to ARB dispersal.Synthesis and applications: The integration of GPS data, pathogen testing and network analyses can shed further light on pathogen dynamics by creating spatial risk maps and identifying ARB sources. In combination with complementary molecular epidemiology techniques within a One Health framework, our approach can emerge as an important tool for monitoring ARB dynamics within highly human‐transformed ecosystems. This may empower managers for the development of targeted ARB monitoring programmes and effective mitigation strategies, ultimately improving both animal and public health. [ABSTRACT FROM AUTHOR]

The European and Japanese eel populations have declined significantly in recent decades. To effectively manage and conserve them, gaining a better understanding of their migratory life cycles is important. Previous research on the spawning ecology and larval dispersal of European and Japanese eels has led to many significant discoveries and advancements for their migratory life cycles. However, different scholars hold varying views on their migratory life cycles, especially concerning the European eel, therefore this article aims to provide a comprehensive review of research from multiple disciplines concerning the spawning ecology and larval dispersal of European and Japanese eels and to propose migratory life cycles of these two species. The migratory life cycle of the European eel is as follows: European silver eels undertake a year‐long spawning migration from September to January to reach the Sargasso Sea for spawning before the next spawning season, typically between December and May. After hatching, European eel leptocephali are transported by the Gulf Stream, Frontal Countercurrents, North Atlantic Current, and Azores Current and return to Europe and North Africa for growth. Recruitment of European glass eels mainly occurs between October and June of the following year, and the recruiting season is more concentrated in countries closer to the spawning area and more dispersed in countries farther away. The consistent recruitment pattern and the growth rate of leptocephali suggest a larval transport period, also called larval duration, of around 1 year. Understanding the migratory life cycle of European eels can facilitate the evaluation or development of their conservation measures. [ABSTRACT FROM AUTHOR]

Tetraploids play a crucial role in the large-scale production of all-triploid Pacific oyster, Crassostrea gigas by mating with diploids. For nursery farms, research related to larval tolerance to the environment appears to be extremely important. For this goal, fertilization, embryonic development, growth, and settlement from fertilization stage to metamorphosis stage of the diploid, triploid, and tetraploid larvae of C. gigas "Haida No. 2" strain were studied under controlled conditions of temperature (20, 24, 28, and 32 ℃) and salinity (18, 21, 24, 27, and 30 psu). The results showed that increasing temperature and lowering salinity reduced survival time of sperm while increasing temperature and raising salinity accelerated the germinal vesicle breakdown (GVBD) ratio of stripped eggs in diploids and tetraploids for the first time. The appropriate condition for hatching of four crosses (DD, DT, TD, and TT, males were listed first, D for diploid, T for tetraploid) were listed as follows: 20–28 ℃/27–30 psu for DD, 24 ℃/27–30 psu for DT, 24–28 ℃/27–30 psu for TD, and 24 ℃/27–30 psu for TT. Diploids and triploids had similar performance but were all better than tetraploids under different temperature and salinity. The settlement rate increased with rising temperature while salinity and ploidy had little influence on settlement. The information obtained in this study can contribute to increasing the yield of triploid and tetraploid "Haida No. 2" of C. gigas. [ABSTRACT FROM AUTHOR]

Patterns of population connectivity shape ecological and evolutionary phenomena from population persistence to local adaptation and can inform conservation strategy. Connectivity patterns emerge from the interaction of individual behavior with a complex and heterogeneous environment. Despite ample observation that dispersal patterns vary through time, the extent to which variation in the physical environment can explain emergent connectivity variation is not clear. Empirical studies of its contribution promise to illuminate a potential source of variability that shapes the dynamics of natural populations. We leveraged simultaneous direct dispersal observations and oceanographic transport simulations of the clownfish Amphiprion clarkii in the Camotes Sea, Philippines, to assess the contribution of oceanographic variability to emergent variation in connectivity. We found that time‐varying oceanographic simulations on both annual and monsoonal timescales partly explained the observed dispersal patterns, suggesting that temporal variation in oceanographic transport shapes connectivity variation on these timescales. However, interannual variation in observed mean dispersal distance was nearly 10 times the expected variation from biophysical simulations, revealing that additional biotic and abiotic factors contribute to interannual connectivity variation. Simulated dispersal kernels also predicted a smaller scale of dispersal than the observations, supporting the hypothesis that undocumented abiotic factors and behaviors such as swimming and navigation enhance the probability of successful dispersal away from, as opposed to retention near, natal sites. Our findings highlight the potential for coincident observations and biophysical simulations to test dispersal hypotheses and the influence of temporal variability on metapopulation persistence, local adaptation, and other population processes. [ABSTRACT FROM AUTHOR]

Approximately 75% of the world's and California's shores are rocky. Rocky shores are of biological interest owing to their diverse and productive species assemblages, where waves and currents play a critical role in larval dispersal and recruitment. Surface variability for nearshore (5⪅depth⪅60m) $(5\lessapprox \mathrm{d}\mathrm{e}\mathrm{p}\mathrm{t}\mathrm{h}\lessapprox 60\hspace*{.5em}\mathrm{m})$ rocky bottoms at intermediate wave scale 1/750

Fish stocks composed of several populations are considered to have more stable productivity than stocks containing only one or few populations. This stability is attributed to complementary or independent dynamics among the populations within the stock—the so-called portfolio effect. Declines of populations within stocks that have delayed recovery potentially increase risk to productivity and local extinctions. Portfolio effects may be relevant in the Baltic Sea, where autumn-spawning herring was the dominant herring ecotype until the early/mid-20th century. The current fishery assessment and management in the area assumes that the abundance of autumn spawning herring has been negligible since the 1970s; the share of spring spawning herring has become dominant and is considered to be the only ecotype. Data from a multi-annual ichthyoplankton survey in the southern Baltic Sea (Bornholm Basin) during autumn 2002–2019 show that abundance and spatial distribution of the smallest larval stages have increased significantly. This pattern could be due to an increase in autumn spawners in the area. Genetic studies confirm that these larval herring are offspring from true autumn spawners. Preserving intraspecific diversity is critical for a species' future abilities to adapt to and survive in changing environmental conditions. Thus, our results not only provide new insights to the temporal dynamics of herring ecotypes and challenge the current understanding of central Baltic herring stock processes in general, but are also important in the context of monitoring, assessment, and spatial management of herring in the Baltic Sea. [ABSTRACT FROM AUTHOR]

Spiny lobster species are ecologically important and highly prized as seafood globally. Populations of spiny lobsters have been impacted by overfishing, the harvesting of juveniles for seeding aquaculture, the spread of virulent disease, and declines in recruitment and natural habitat. Many spiny lobster populations cover vast geographic ranges, maintained via ocean-going larval dispersal, which makes effective management challenging. Determining the genetic structure and phylogeographic boundaries are important in fisheries and aquaculture for defining appropriate units for management or breeding. Nevertheless, the common patterns of biogeographic distribution and connectivity of spiny lobster populations are generally not well understood. This review summarizes recent genetic advances in our understanding of these patterns and presents several meta-analyses to help discern the common processes driving them. Due to the probable link between biogeographic patterns among species and phylogeographic patterns within species, the spatial patterns of recent genetic stock divergence were investigated with the assistance of a new comprehensive and time-calibrated phylogeny for palinurids. Meta-analyses of biogeographic and phylogeographic patterns were used to identify common patterns of genetic stock divergence. A model is proposed that synthesizes the current understanding of the common processes of divergence of palinurid genetic lineages, emphasizing the importance of allopatry, ecological adaptation, and changing patterns of connectivity over time. Overall, the results highlight the importance of major biogeographic boundaries in structuring spiny lobster stocks over a broad scale, while oceanographic features and stochasticity dominate at smaller scales. These insights will assist the management of spiny lobster fisheries and aquaculture development, by better identifying and understanding the genetic units expected to be most appropriate for management and breeding, even in those species that have not yet received intensive genetic study. [ABSTRACT FROM AUTHOR]

Aim: In order to provide a more comprehensive, community‐level understanding of marine gene flow and connectivity, we wished to first identify geographic regions of common spatial genetic divergence across multiple species along a southern temperate coastline, and then to determine which biological and ecological factors best explain the diversity in genetic patterns among species. Location: New Zealand (NZ) marine coastline. Taxon: Twenty‐one species of benthic invertebrate. Materials and Methods: A novel approach was used that involved: (1) use of genetic divergences (FST) from previously published studies to quantitatively describe patterns of population structure within each species as a fitted spline curve, (2) quantitatively clustering species by their similarity in geographic pattern using a dendrogram of curve similarities, and (3) then testing whether nine known life‐history and ecological traits are associated with the species sharing similar genetic patterns, using distance‐based regression. Results: Comparisons among species revealed not one, but four major common geographic patterns, within unexpected groups of species. The common locations of genetic divergence are similar to those previously identified, but differ substantially in their relative importance, compared to prior expectations. Two variables, Spawning Time and Taxon, explained significant proportions (26% and 16%) of the variation in the multivariate data. Main Conclusions: The genogeographic clustering of population genetic divergences provided considerable insight into the concordance of marine spatial structure across species, and some potential biological drivers of those patterns. The four common patterns of population structure identified revealed that different species responded to the same environmental drivers in very different and unexpected ways. Although larval dispersal is an important factor uniting groups of species, the timing of dispersal may be more important than pelagic larval duration in NZ. These results should contribute greatly to the integration of population genetics into both community ecology and conservation management. [ABSTRACT FROM AUTHOR]

While the interbreeding of Homo neanderthalensis (hereafter Neanderthal) and Anatomically modern human (AMH) has been proven, owing to the shortage of fossils and absence of appropriate DNA, the timing and geography of their interbreeding are not clearly known. In this study, we applied ecological niche modelling (maximum entropy approach) and GIS to reconstruct the palaeodistribution of Neanderthals and AMHs in Southwest Asia and Southeast Europe and identify their contact and potential interbreeding zone during marine isotope stage 5 (MIS 5), when the second wave of interbreeding occurred. We used climatic variables characterizing the environmental conditions of MIS 5 ca. 120 to 80 kyr (averaged value) along with the topography and coordinates of Neanderthal and modern human archaeological sites to characterize the palaeodistribution of each species. Overlapping the models revealed that the Zagros Mountains were a contact and potential interbreeding zone for the two human species. We believe that the Zagros Mountains acted as a corridor connecting the Palearctic/Afrotropical realms, facilitating northwards dispersal of AMHs and southwards dispersal of Neanderthals during MIS 5. Our analyses are comparable with archaeological and genetic evidence collected during recent decades. [ABSTRACT FROM AUTHOR]

Gene flow is important for maintaining the genetic diversity required for adaptation to environmental disturbances, though gene flow may be limited by site fidelity in small coastal sharks. Bonnethead sharks (Sphyrna tiburo)—a small coastal hammerhead species—demonstrate site fidelity, as females are philopatric while males migrate to mediate gene flow. Consequently, bonnetheads demonstrate population divergence with distance, and Atlantic populations are genetically distinct from those of the Gulf of Mexico. Indeed, Florida forms a vicariant zone between these two bodies of water for many marine species, including some sharks. However, while bonnetheads are expected to have limited dispersal, the extent and rate of bonnethead migration remain uncertain. Thus, we aimed to determine their dispersal capacity by evaluating connectivity between disparate populations from the Gulf of Mexico and Atlantic Ocean. Using 10,733 SNPs derived from 2bRAD sequences, we evaluated genetic connectivity between Tampa Bay on the Gulf Coast of Florida and Biscayne Bay on the Atlantic coast of Florida. While standard analyses of genetic structure revealed slight but significant differentiation between Tampa Bay and Biscayne Bay populations, demographic history inference based on the site frequency spectrum favored a model without divergence. However, we also estimate that if population divergence occurred, it would have been recent (between 1500 and 4500 years ago), with continuous unidirectional gene flow from Tampa Bay to Biscayne Bay. Our findings support the hypothesis that bonnetheads can migrate over relatively large distances (>300 miles) to find mates. Together, these results provide optimism that under proper management, a small‐bodied globally endangered shark can undergo long migrations to sustain genetic diversity. [ABSTRACT FROM AUTHOR]

For marine species with planktonic dispersal, invasion of open ocean coastlines is impaired by the physical adversity of ocean currents moving larvae downstream and offshore. The extent species are affected by physical adversity depends on interactions of the currents with larval life history traits such as planktonic duration, depth and seasonality. Ecologists have struggled to understand how these traits expose species to adverse ocean currents and affect their ability to persist when introduced to novel habitat. We use a high‐resolution global ocean model to isolate the role of ocean currents on the persistence of a larval‐producing species introduced to every open coastline of the world. We find physical adversity to invasion varies globally by several orders of magnitude. Larval duration is the most influential life history trait because increased duration prolongs species' exposure to ocean currents. Furthermore, variation of physical adversity with life history elucidates how trade‐offs between dispersal traits vary globally. [ABSTRACT FROM AUTHOR]

Signals of natural selection can be quickly eroded in high gene flow systems, curtailing efforts to understand how and when genetic adaptation occurs in the ocean. This long‐standing, unresolved topic in ecology and evolution has renewed importance because changing environmental conditions are driving range expansions that may necessitate rapid evolutionary responses. One example occurs in Kellet's whelk (Kelletia kelletii), a common subtidal gastropod with an ~40‐ to 60‐day pelagic larval duration that expanded their biogeographic range northwards in the 1970s by over 300 km. To test for genetic adaptation, we performed a series of experimental crosses with Kellet's whelk adults collected from their historical (HxH) and recently expanded range (ExE), and conducted RNA‐Seq on offspring that we reared in a common garden environment. We identified 2770 differentially expressed genes (DEGs) between 54 offspring samples with either only historical range (HxH offspring) or expanded range (ExE offspring) ancestry. Using SNPs called directly from the DEGs, we assigned samples of known origin back to their range of origin with unprecedented accuracy for a marine species (92.6% and 94.5% for HxH and ExE offspring, respectively). The SNP with the highest predictive importance occurred on triosephosphate isomerase (TPI), an essential metabolic enzyme involved in cold stress response. TPI was significantly upregulated and contained a non‐synonymous mutation in the expanded range. Our findings pave the way for accurately identifying patterns of dispersal, gene flow and population connectivity in the ocean by demonstrating that experimental transcriptomics can reveal mechanisms for how marine organisms respond to changing environmental conditions. [ABSTRACT FROM AUTHOR]

Computing Lagrangian trajectories with ocean circulation models is a powerful way to infer larval dispersal pathways and connectivity. Defining release areas and timing of particles to represent larval habitat realistically is critical to obtaining representative dispersal pathways. However, it is challenging due to spatial and temporal variability in larval density. Forward-tracking particle experiments were conducted to study larval connectivity of four species (neritic or mesopelagic) in the Gulf of Mexico's (GoM) deep-water region. A seasonal climatology coupled with predicted potential larval habitat models based on generalized additive models was used to delimit the particle dispersal origin. Two contrasting mesoscale circulation patterns were examined: (1) high Loop Current (LC) intrusion, absence of recently detached LC anticyclonic eddies (LC-ACE), and no interaction between LC-ACEs and the semi-permanent cyclonic eddy (CE) in the Bay of Campeche (BoC), and (2) limited LC intrusion, a recently detached LC-ACE, and interaction between LC-ACEs and the BoC's CE. To simulate larval transport, virtual larvae were randomly released in the potential habitats and advected for 30 days with the velocity fields of the HYbrid Coordinate Ocean Model with hourly-resolution assimilation. Potential habitat location and size played a major role in dispersal and connectivity. A greater percentage of particles were retained in potential habitats restricted to the southern BoC, suggesting lower connectivity with other GoM regions than those encompassing most of the BoC or the central Gulf. Mesoscale feature interactions in the western GoM and BoC led to greater dispersion along the western basin. By contrast, the absence of ACE-CE interaction in the BoC led to greater retention and less connectivity between the southern and northern GoM. Under high LC intrusion, particles seeded north of the Yucatan Shelf were advected through the Florida Straits and dispersed within the GoM. Coupling potential habitat models with particle experiments can help characterize the dispersal and connectivity of fish larvae in oceanic systems. [ABSTRACT FROM AUTHOR]

Most ecological studies attempting to understand causes of population dynamics and community structure disregard intraspecific trait variation. We quantified the importance of natural intra‐cohort variation in body size and density of juveniles for recruitment of a sessile marine organism, the barnacle Semibalanus balanoides. Barnacles are representative of species organised in metapopulations, that is, as open local populations connected by larval dispersal. We tracked the individual growth and survival of a cohort of juvenile barnacles from two shores of North Wales. Barnacles settled as larvae in spring of 2002 on previously cleared rock. The density of these new recruits was experimentally manipulated in June and randomly selected individuals were monitored from June to October to evaluate the role of barnacle size and density in predicting survival. In doing so we characterised density at three spatial scales (quadrat: 25 cm2, cells within quadrats: 25 mm2 and neighbourhood: number of neighbours in physical contact with the target barnacle). At all scales, variations in juvenile body size exacerbated the effect of density‐dependent mortality on population size. While density‐dependent mortality was very intense in the small‐sized individuals, large‐sized individuals experienced very weak density‐dependent mortality and showed high survival rates. Using the concept of 'Jensen inequality', we show that important biases in estimations of survival, based on population size only, occur at high barnacle densities, where survival is low. Our study highlights the role of body size variation in understanding dynamics of open populations. [ABSTRACT FROM AUTHOR]

Many coastal marine species have discontinuous distributions or genetic breakpoints throughout their geographical ranges. These spatial and genetic disjunctions occur in species that span limited to broad dispersal potential. Thus, the mechanisms that underlie these disjunctions remain speculative or incompletely known, particularly on small spatial scales where long-term historical processes are unlikely to be the only mechanism contributing to disjunction. Rather, ecological or oceanographic factors may be important. To identify key drivers of coastal disjunctions, we reviewed publications investigating spatial and genetic disjunctions in coastal marine species and visually summarized where and why they are thought to occur. The most frequently cited mechanisms implicated in causing disjunctions include historical processes, oceanographic features, heterogeneous habitat, species introductions, and limited larval dispersal capacities. However, the relative importance of each of these processes varies depending on the spatial scales investigated. Furthermore, locations associated with disjunctions for a suite of species are typically associated with multiple processes that maintain these disjunctions. This study provides a non-exhaustive synthesis of disjunctions in coastal marine species by visualizing where they occur, exploring underlying mechanisms, and investigating biases in how the scientific community studies this phenomenon. [ABSTRACT FROM AUTHOR]

Blow flies (Diptera: Calliphoridae) are arguably the most important providers of an estimate of minimum post‐mortem interval in forensic investigations. They usually undergo a post‐feeding dispersal from the body. While previous studies have looked at dispersal of groups of larvae, recording the dispersal activity of individual larvae has not previously been demonstrated. A servosphere was used here to record the speed, directionality and phototaxis of individual post‐feeding larvae of two species of blow fly on a smooth plastic surface over time. The servosphere rotates to compensate for the movement of an insect placed at its apex, thereby enabling its unimpeded locomotion in any direction to be studied and behavioural changes to external stimuli recorded. To our knowledge, the servosphere has not previously been used to study apodous insects. The objective of our study was to compare dispersal behaviour of Calliphora vicina Robineau‐Desvoidy and Protophormia terraenovae (Robineau‐Desvoidy), both common primary colonisers of human and animal cadavers, but showing different post‐feeding dispersal strategies. Larvae of C. vicina generally disperse from the body while those of P. terraenovae remain on or close to the body. Our aims were to study (1) changes in dispersal speed over a 1‐h period; (2) changes in dispersal speed once a day for 4 days, between the end of feeding and onset of pupariation; and (3) response of dispersing larvae to light. We demonstrated that (1) the movement of three C. vicina larvae tracked for 1 continuous hour on 1 day slowed from an average of 3 to <1.7 mms−1; (2) the average speed of 20 larvae of C. vicina (4.08 mms−1) recorded for 5 min once per day over a 4‐day period between onset of dispersal and pupariation was significantly greater than that of P. terraenovae (2.36 mms−1; p < 0.0001), but that speed of both species increased slightly over the 4 days; (3) the responses of larvae of C. vicina to changes in light direction from the four cardinal directions of the compass, showed that they exhibited a strong negative phototactic response within 5 s, turning to move at approximately 180° away from the new light position. While conducted to observe larval calliphorid post‐feeding behaviour, the results of this proof of concept study show that apodous insects can be studied on a servosphere to produce both qualitative and quantitative data. [ABSTRACT FROM AUTHOR]

Slow-wave sleep (SWS), characterized by slow oscillations (SOs, <1Hz) of alternating active and silent states in the thalamocortical network, is a primary brain state during Non-Rapid Eye Movement (NREM) sleep. In the last two decades, the traditional view of SWS as a global and uniform whole-brain state has been challenged by a growing body of evidence indicating that SO can be local and can coexist with wake-like activity. However, the mechanisms by which global and local SOs arise from micro-scale neuronal dynamics and network connectivity remain poorly understood. We developed a multi-scale, biophysically realistic human whole-brain thalamocortical network model capable of transitioning between the awake state and SWS, and we investigated the role of connectivity in the spatio-temporal dynamics of sleep SO. We found that the overall strength and a relative balance between long and short-range synaptic connections determined the network state. Importantly, for a range of synaptic strengths, the model demonstrated complex mixed SO states, where periods of synchronized global slow-wave activity were intermittent with the periods of asynchronous local slow-waves. An increase in the overall synaptic strength led to synchronized global SO, while a decrease in synaptic connectivity produced only local slow-waves that would not propagate beyond local areas. These results were compared to human data to validate probable models of biophysically realistic SO. The model producing mixed states provided the best match to the spatial coherence profile and the functional connectivity estimated from human subjects. These findings shed light on how the spatio-temporal properties of SO emerge from local and global cortical connectivity and provide a framework for further exploring the mechanisms and functions of SWS in health and disease. Author summary: Slow Wave Sleep (SWS) is a primary brain state found during Non-Rapid Eye Movement (NREM) sleep. While previously thought of as homogeneous waves of activity that sweep across the entire brain, recent research has suggested a more nuanced pattern of activity that can vary between local and global slow waves. However, understanding how these states emerge from small-scale neuronal dynamics and network connectivity remains unclear. We developed a biophysically realistic model of the human brain capable of generating SWS-like behavior and investigated the role of connectivity in the spatio-temporal dynamics of the sleep slow waves. We found that the overall strength and relative balance between long and short-range synaptic connections determined the network behavior—specifically, models with relatively weaker long-range connectivity resulted in mixed states of global and local slow waves. Comparing these results to human data, we found that models producing mixed states best matched the network behavior and functional connectivity observed in human subjects. These findings shed light on how the spatio-temporal properties of SWS emerge from local and global cortical connectivity and provide a framework for further exploring the mechanisms and functions of SWS in health and disease. [ABSTRACT FROM AUTHOR]

Eusocial insects belong to distinct queen and worker castes, which, in turn, can be divided into several morphologically specialized castes of workers. Caste determination typically occurs by differential nutrition of developing larvae. We present a model for the coevolution of larval signalling and worker task allocation—both modelled by flexible smooth reaction norms—to investigate the evolution of caste determination mechanisms and worker polymorphism. In our model, larvae evolve to signal their nutritional state to workers. The workers evolve to allocate time to foraging for resources versus feeding the brood, conditional on the larval signals and their body size. Worker polymorphism evolves under accelerating foraging returns of increasing body size, which causes selection to favour large foraging and small nursing workers. Worker castes emerge because larvae evolve to amplify their signals after obtaining some food, which causes them to receive more food, while the other larvae remain unfed. This leads to symmetry-breaking among the larvae, which are either well-nourished or malnourished, thus emerging as small or large workers. Our model demonstrates the evolution of nutrition-dependent caste determination and worker polymorphism by a self-reinforcement mechanism that evolves from the interplay of larval signalling and worker response to the signals. [ABSTRACT FROM AUTHOR]

Solanine (SOL) and chaconine (CHA) are glycoalkaloids (GAs) produced mainly by Solanum plants. These plant secondary metabolites affect insect metabolism; thus, they have the potential to be applied as natural plant protection products. However, it is not known which GA concentration induces physiological changes in animals. Therefore, the aim of this study was to perform a quantitative analysis of SOL and CHA in the larvae of Tenebrio molitor using LC‒MS to assess how quickly they are eliminated or metabolised. In this experiment, the beetles were injected with 2 μL of 10−5 M SOL or CHA solution, which corresponds to a dosage range of 0.12–0.14 ng/mg body mass. Then, 0.5, 1.5, 8, and 24 h after GA application, the haemolymph (H), gut (G), and the remainder of the larval body (FB) were isolated. GAs were detected in all samples tested for 24 h, with the highest percentage of the amount applied in the FB, while the highest concentration was measured in the H sample. The SOL and CHA concentrations decreased in the haemolymph over time, while they did not change in other tissues. CHA had the highest elimination rate immediately after injection, while SOL slightly later. None of the GA hydrolysis products were detected in the tested samples. One possible mechanism of the detoxification of GAs may be oxidation and/or sequestration. They may be excreted by Malpighian tubules, with faeces or with cuticles during moulting. The results presented are significant because they facilitate the interpretation of studies related to the effects of toxic substances on insect metabolism. [ABSTRACT FROM AUTHOR]

The sex of Lepidoptera species can typically be identified at the pupal or adult stage by their morphological characteristics. However, for most species, no obvious sex‐specific traits can be used at the larval or embryonic stage. The growing interest in studying sex determination and differentiation, along with the potential application of research findings in genetic regulation techniques, is promoting the advancement of new sexing methods at early developmental stages. In this study, the sex of individual eggs and larvae was successfully identified by means of W chromosome molecular markers, which were identified through analysing the previously published W chromosome sequence data of Spodoptera frugiperda (Lepidoptera: Noctuidae). Additionally, we present methods to extract DNA and RNA from individual eggs and larval hemolymph. These techniques provide a simple and dependable method to identify sex at pre‐pupal stages. This approach could potentially be extended to other Lepidoptera species of which the W chromosome information is available. [ABSTRACT FROM AUTHOR]

The seascapes of Small Island Developing States are at risk from anthropogenic pollution. To implement effective seascape management, there is a need to better understand the threats to the seascape, subsequent impacts and associated stakeholder perceptions. This study used a systematic literature review, online survey and follow-up interviews to identify the main threats and impacts to the seascape and analyze associated perceptions of stakeholders, using Mauritius as a case study. The key threats were found to be oil spills, anthropogenic marine debris, coastal development, tourism, poor environmental management, and inadequate enforcement of legislation. Associated perception data showed a high awareness of increasing pollution, some awareness of the impacts and a general consensus that the seascape is poorly managed. Stricter law enforcement and increased education were suggested by stakeholders to improve seascape management. It is hoped this data will inform future studies and subsequently improve the effectiveness of seascape management. [ABSTRACT FROM AUTHOR]

Myzostoma khanhkhoaense is a cyst-to-free-moving myzostomid associated with the comatulid crinoid Clarkcomanthus albinotus. It induces deformations of the skeletal elements of the host's arms, thereby making protective "baskets" in which to hide from predators. Each "basket" is inhabited by a dense aggregation up to 25 worms of different sizes. The size-abundance structure of some subpopulations (these being defined as the inhabitants of one host) shows a clear peak, which may be related to the worm's reproductive cycle. Some subpopulations show two such peaks, which may be evidence of colonization by two different generations of worms. No subpopulations with more than two peaks were found, what is probably an indication that these worms have a short lifetime. We believe that a newly settled generation of M. khanhkhoaense undergoes no more than two reproductive cycles, starting with initial settlement, growth, and reproduction, and then — evident as the larger-size peak if a second generation of larvae settles on the same host — another round of growth and reproduction, and finally death. [ABSTRACT FROM AUTHOR]

Tenebrio molitor gained recognition for its nutritional value for human and/or animal consumption, its utilization as a model species in research studies, and its ability to degrade many types of plastics. However, it is a stored-product pest infesting a wide range of commodities in storages. The impact of temperature on the development of T. molitor was evaluated, taking into account confounding effects of other covariates such as developmental stage and larval instar. The time for larval development was longer at 22.5 °C than at 25 °C, 27.5 °C, and 30 °C. Tenebrio molitor spent most of its lifetime as larva > egg, pupa, since the outcome of our model inference resulted that the estimated probability of longer duration in larvae is approximately 25.5 times higher compared to eggs and pupae, and passed through 26 instars before it became pupa. Duration of larval instars increased significantly up to L22 and then decreased until L26. Among larval instars, L22 exhibited the highest developmental duration while the lowest was recorded for L1. These findings enhance the knowledge about the biology of T. molitor, leading to precise decisions for its successful culture. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing interest in exploring novel natural sources for antioxidant and anti-inflammatory agents, driven by the need for alternative therapeutic strategies with fewer side effects. This study investigates the potential of the Biomphalaria alexandrina snail as a valuable model organism to evaluate the antioxidant and anti-inflammatory properties of Sarcophaga argyrostoma larval hemolymph. The choice of B. alexandrina snails as a model is based on its ecological relevance and physiological similarities to other organisms, supporting well-established use in ecological and physiological research, as well as it provides a valuable platform for such investigations. Ultimately, this study may open avenues for the development of innovative and sustainable therapeutic interventions rooted in the rich biodiversity of the natural world. The experimental design involves the extraction of hemolymph from S. argyrostoma larvae, followed by a comprehensive analysis of its antioxidant capacity and anti-inflammatory effects using adult snails. Various biochemical assays, including total antioxidant capacity, immunomodulatory markers and histological investigation, will be employed to assess the bioactive potential of the hemolymph. The outcomes of this research can be attributed to the identification of the anti-oxidant and anti-inflammatory effects of hemolymph. This effect was observed through the reduction of oxidative stress and proinflammatory mediators, impacting the biological activities of the snails. The study is the first to shed light on the potential benefits of S. argyrostoma larval hemolymph using an animal model, showcasing its ability to mitigate oxidative and inflammatory responses within the biological context of the snails. [ABSTRACT FROM AUTHOR]

Seagrass beds are ecologically and economically important coastal ecosystems, and seagrass-associated organisms are a key part of their biodiversity. Marine organisms that reproduce through broadcast spawning are likely to have less genetic differentiation among populations than those that use other modes of reproduction, but this has not been well studied. Here, we investigated the genetic diversity, genetic differentiation, and migration patterns of the seagrass-associated sea star Protoreaster nodosus across 12 sites spanning approximately 2500 km from the Ryukyu Archipelago, Japan, to the Philippines. We genotyped 405 individuals by using seven microsatellite loci and analyzed allelic richness and expected heterozygosity as indices of genetic diversity. Of these two indices, only expected heterozygosity decreased slightly with increasing latitude. These results suggest that genetic diversity has not clearly decreased, even in the isolated Ryukyu Archipelago populations. Geographic distance was significantly correlated with genetic differentiation (pairwise FST: − 0.005 to 0.049). However, populations in the Ryukyu Archipelago and the Philippines showed relatively low genetic structuring and the pairwise genetic differentiation between these regions was often non-significant. Analysis of historical migration rates showed bidirectional north–south migration, which appears to be influenced by the Kuroshio Current and its countercurrents. [ABSTRACT FROM AUTHOR]

For species of management concern, accurate estimates of inbreeding and associated consequences on reproduction are crucial for predicting their future viability. However, few studies have partitioned this aspect of genetic viability with respect to reproduction in a group-living social mammal. We investigated the contributions of foundation stock lineages, putative fitness consequences of inbreeding, and genetic diversity of the breeding versus nonreproductive segment of the Yellowstone National Park gray wolf population. Our dataset spans 25 years and seven generations since reintroduction, encompassing 152 nuclear families and 329 litters. We found more than 87% of the pedigree foundation genomes persisted and report influxes of allelic diversity from two translocated wolves from a divergent source in Montana. As expected for group-living species, mean kinship significantly increased over time but with minimal loss of observed heterozygosity. Strikingly, the reproductive portion of the population carried a significantly lower genome-wide inbreeding coefficients, autozygosity, and more rapid decay for linkage disequilibrium relative to the nonbreeding population. Breeding wolves had significantly longer lifespans and lower inbreeding coefficients than nonbreeding wolves. Our model revealed that the number of litters was negatively significantly associated with heterozygosity (R  = −0.11). Our findings highlight genetic contributions to fitness, and the importance of the reproductively active individuals in a population to counteract loss of genetic variation in a wild, free-ranging social carnivore. It is crucial for managers to mitigate factors that significantly reduce effective population size and genetic connectivity, which supports the dispersion of genetic variation that aids in rapid evolutionary responses to environmental challenges. [ABSTRACT FROM AUTHOR]

Octopuses are amongst the most fascinating animals in our oceans; however, while their intricate behaviours are often studied in laboratory settings, basic aspects of their movement ecology remain unstudied in the wild. Focusing on the socio-economically important common octopus (Octopus vulgaris), this study employs, for the first time, acoustic tracking techniques to address knowledge gaps regarding the species spatial ecology within a marine protected area. A total of 24 wild O. vulgaris (13 males, 11 females) were tagged in 2022 in the National Park Maritime-Terrestrial of the Atlantic Islands of Galicia, Spain. Acoustic transmitters were externally attached to the third arm, after testing other body parts (mantle cavity). Males were on average detected on 10 times more occasions than females (49 days in males and five in females). The average activity space in the study area was large in comparison to that determined in similar studies, with 0.16 km2. Activity space between males and females as well as day and night were comparable. Tagged octopuses displayed a crepuscular activity pattern. The location of dens could be established for 15 out of 24 individuals, from which octopuses were observed to undertake regular daytime excursions. Several individuals were also found to occupy more than one den and/or switch their main dens throughout the study duration. First implications and benefits of this approach are discussed. [ABSTRACT FROM AUTHOR]

Understanding population connectivity helps inform resource and conservation managers about appropriate boundaries for management units. However, for many species facing recent increases in fishing or environmental pressure, accurate information on population structure is lacking. Reef Bugs (Thenus australiensis), commonly known as Moreton Bay Bugs, are iconic shovel-nosed lobsters in northern Australia and an increasingly important fisheries resource. Around 80% of landings occur in the Queensland East Coast Otter Trawl Fishery (ECOTF) where the first stock assessment of the species is underway. However, knowledge about population structure to inform stock assessment is lacking. We used genome complexity reduction-based sequencing to characterise high-quality Single Nucleotide Polymorphisms (SNPs) used to evaluate population structure among three management zones of the ECOTF. Post-filtering, a total of 3,031 SNPs were used to infer no genetic differences among locations indicating strong genetic population connectivity. The presence of a single panmictic population was further supported by cluster and kinship analyses. Broad-scale genetic connectivity likely results from pelagic larval dispersal due to limited adult movements. Findings of high gene flow among connected populations indicate a single biological stock of T. australiensis on Australia's east coast and will inform future fisheries management initiatives. [ABSTRACT FROM AUTHOR]

As in most colonial and sessile marine invertebrates, bryozoan life history is characterized by asexual propagation of zooids for colonial growth and by sexual production of larvae for dispersal. However, comprehensive life histories, particularly in cryptic species such as endolithic (boring) bryozoans, remain poorly understood. The ctenostome family Penetrantiidae is widespread from temperate to tropical waters and often found in molluscan shells, offering an opportunity to study the boring lifestyle and its potential impact on bioerosion through growth and settlement experiments. Our research focused on Penetrantia clionoides from Guam in the Pacific Ocean, Penetrantia japonica from Japan, and a Penetrantia species from France in the Atlantic Ocean. We found distinct life histories and reproductive patterns potentially influenced by environmental factors such as temperature and food availability. The tropical P. clionoides displayed higher rates of larval production and growth compared to its temperate counterpart. For instance, the mean stolon extension was 335.2 μm/week in P. clionoides versus 232.1 μm/week in Penetrantia sp. Autozooid development took 13 days in P. clionoides and 31 days in Penetrantia sp. Anatomical features like apertural rims aided in species identification and in understanding larval settlement preferences, suggesting a tendency for philopatric settlement behavior. The bioerosional impact of penetrantiids remains little understood, but we generated first projections of bioerosion rates and a protocol for keeping Penetrantia under laboratory conditions, laying a foundation for further research in this field. [ABSTRACT FROM AUTHOR]

Patterns of genetic variation reflect interactions among microevolutionary forces that vary in strength with changing demography. Here, patterns of variation within and among samples of the mouthbrooding gafftopsail catfish (Bagre marinus, Family Ariidae) captured in the U.S. Atlantic and throughout the Gulf of Mexico were analyzed using genomics to generate neutral and non‐neutral SNP data sets. Because genomic resources are lacking for ariids, linkage disequilibrium network analysis was used to examine patterns of putatively adaptive variation. Finally, historical demographic parameters were estimated from site frequency spectra. The results show four differentiated groups, corresponding to the (1) U.S. Atlantic, and the (2) northeastern, (3) northwestern, and (4) southern Gulf of Mexico. The non‐neutral data presented two contrasting signals of structure, one due to increases in diversity moving west to east and north to south, and another to increased heterozygosity in the Atlantic. Demographic analysis suggested that recently reduced long‐term effective population size in the Atlantic is likely an important driver of patterns of genetic variation and is consistent with a known reduction in population size potentially due to an epizootic. Overall, patterns of genetic variation resemble that of other fishes that use the same estuarine habitats as nurseries, regardless of the presence/absence of a larval phase, supporting the idea that adult/juvenile behavior and habitat are important predictors of contemporary patterns of genetic structure. Gafftopsail catfish show high levels of genetic structuring across their distribution in the U.S., Atlantic and Gulf of Mexico. Non‐neutral data present two contrasting signals of structure and historical demography is likely an important driver of patterns of neutral and non‐neutral genetic variation. Results of this study are similar to what is seen in other fishes that use the same estuarine habitats as nurseries, but gafftopsail catfish lack a larval phase, supporting the idea that adult/juvenile behavior and habitat use are important predictors of contemporary patterns of genetic structure. [ABSTRACT FROM AUTHOR]

Background: The influence of native secondary succession associated with anthropogenic disturbance on the biodiversity of the forests in subtropical China remains uncertain. In particular, the evolutionary response of small understory shrubs, particularly pioneer species inhabiting continuously disturbed habitats, to topographic heterogeneity and climate change is poorly understood. This study aimed to address this knowledge gap by focusing on the Gaultheria crenulata group, a clade of small pioneer shrubs in subtropical China. Results: We examined the genetic structure and demographic history of all five species of the G. crenulata group with two maternally inherited chloroplast DNA (cpDNA) fragments and two biparentally inherited low-copy nuclear genes (LCG) over 89 natural populations. We found that the genetic differentiation of this group was influenced by the geomorphological boundary between different regions of China in association with Quaternary climatic events. Despite low overall genetic diversity, we observed an isolation-by-distance (IBD) pattern at a regional scale, rather than isolation-by-environment (IBE), which was attributed to ongoing human disturbance in the region. Conclusion: Our findings suggest that the genetic structure of the G. crenulata group reflects the interplay of geological topography, historical climates, and anthropogenic disturbance during the Pliocene–Pleistocene-Holocene periods in subtropical China. The observed IBD pattern, particularly prominent in western China, highlights the role of limited dispersal and gene flow, possibly influenced by physical barriers or decreased connectivity over geographic distance. Furthermore, the east-to-west trend of gene flow, potentially facilitated by the East Asian monsoon system, underscores the complex interplay of biotic and abiotic factors shaping the genetic dynamics of pioneer species in subtropical China's secondary forests. These findings can be used to assess the impact of environmental changes on the adaptation and persistence of biodiversity in subtropical forest ecosystems. [ABSTRACT FROM AUTHOR]

The sea cucumber Holothuria inornata is a species whose populations are at risk. This study aims to investigate its reproduction, embryonic and larval development, and the settlement of H. inornata under an algae-based diet. Twenty breeders were utilized, which underwent a 1.5-h desiccation followed by a thermal shock (27 to 32 °C). Embryonic development stage was recorded, and from the auricularia larval stage, three treatments were evaluated: A: Chaetoceros muelleri and Isochrysis galbana (1:1 ratio); B: C. muelleri, I. galbana, Tetraselmis suecica, and Pavlova lutheri (1:1:1:1 ratio); and C: Chaetoceros muelleri, I. galbana, T. suecica, P. lutheri, Navicula sp. (LPU-6) (1:1:1:1:1 ratio), with a larval density of 100 larvae L−1 in triplicate. The embryonic development in H. inornata lasts for 3 days, five larval stages were recorded: (1) Auricularia (days 3–8, 300 to 520 μm), (2) late auricularia (days 8–11, 520 to 670 μm), (3) doliolaria (days 11–13, 460 to 550 μm), (4) late doliolaria (days 13–16, 400 to 440 μm), and (5) pentacula (days 15–19, 650 to 900 μm). The post-settlement survival rate was 0% under treatment A, 2.38 ± 0.16% under treatment B, and 3.79 ± 0.41% under treatment C. Based on these findings, we concluded that H. inornata specie spawn through a combined desiccation-thermal shock process with a larval period of up to 19 days, and subsequently produce juvenile individuals in captivity with a varied microalgae diet. [ABSTRACT FROM AUTHOR]

Climate change poses an existential threat to coral reefs. A warmer and more acidic ocean weakens coral ecosystems and increases the intensity of hurricanes. The wind–wave–current interactions during a hurricane deeply change the ocean circulation patterns and hence potentially affect the dispersal of coral larvae and coral disease agents. Here, we modeled the impact of major hurricane Irma (September 2017) on coral larval and stony coral tissue loss disease (SCTLD) connectivity in Florida's Coral Reef. We coupled high‐resolution coastal ocean circulation and wave models to simulate the dispersal of virtual coral larvae and disease agents between thousands of reefs. While being a brief event, our results suggest the passage of hurricane Irma strongly increased the probability of long‐distance exchanges while reducing larval supply. It created new connections that could promote coral resilience but also probably accelerated the spread of SCTLD by about a month. As they become more intense, hurricanes' double‐edged effect will become increasingly pronounced, contributing to increased variability in transport patterns and an accelerated rate of change within coral reef ecosystems. [ABSTRACT FROM AUTHOR]

Since recolonizing the seas, most teleosts evolved as pelagophils, producing highly hydrated pelagic (buoyant) eggs. Osmotic drive for oocyte hydration is mainly generated through differential proteolysis of vitellogenin-Aa-derived yolk proteins. Teleost-specific water channels are selectively retained in pelagophils and coevolved with 14-3-3ζ-like binding proteins to co-operatively regulate channel trafficking in a manner that avoids competitive membrane space occupancy and accelerates oocyte water influx. Gonadotropinergic and vasopressinergic systemic and paracrine signaling systems converge to activate meiosis resumption and oocyte hydration. Developmental downregulation of dominant-negative inhibitory aquaporin variants maximizes oocyte hydration. These innovative genetic adaptations are highly conserved in modern marine teleosts, contributing to the success of their eggs in the oceans. Genetic adaptations of organisms living in extreme environments are fundamental to our understanding of where life can evolve. Water is the single limiting parameter in this regard, yet when released in the oceans, the single-celled eggs of marine bony fishes (teleosts) have no means of acquiring it. They are strongly hyposmotic to seawater and lack osmoregulatory systems. Paradoxically, modern teleosts successfully release vast quantities of eggs in the extreme saline environment and recorded the most explosive radiation in vertebrate history. Here, we highlight key genetic adaptations that evolved to solve this paradox by filling the pre-ovulated eggs with water. The degree of water acquisition is uniquely prevalent to marine teleosts, permitting the survival and oceanic dispersal of their eggs. [ABSTRACT FROM AUTHOR]