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Gut contents and nitrogen isotope ratio (δ15N) analyses were conducted on splendid alfonsino Beryx splendens collected in the vicinity of Kuroshio from May 2015 to November 2016 (n = 708) to identify their feeding habits in the Western North Pacific. Micronektonic fish, shrimp, and squid were the dominant prey species, with the Decapoda Acanthephyra quadrispinosa, Prehensilosergia prehensilis, Cephalopoda Enoploteuthis chunii, Chiroteuthis calyx, Teleostei Sigmops gracilis, and Gonostoma elongatum. These micronektons are common in the Kuroshio Current; thus, B. splendens is a possible opportunistic feeder. Gut content weight (GCW), occurrence (%O) of fish and squid, and δ15N were significantly increased with the fork length (FL) of B. splendens. Only the %O of shrimp does not show a significant relationship with the FL of B. splendens. These indicated the ontogenetic shift of dominant prey from shrimp to fish. Fattened specimens could also prey on a greater number of fish. The seasonality of GCW and %O values was high in spring and autumn and low in summer and winter. This seasonality indicated that the feeding habits of B. splendens are controlled by primary productivity in the surface layer and/or by maturity. When the Kuroshio flowed in the north of Hachijojima Island, the GCW was significantly increased, and some organisms, including C. calyx, G. elongatum, and S. gracilis, were preyed on more. While the offshore area of the Kuroshio has low productivity, B. splendens can actively prey in this area, indicating that it is an important feeding ground for this species. [ABSTRACT FROM AUTHOR]

ABSTRACT Gut mycobiota are part of the gut microbiome, typically derived from the host diet and living environment. In this study, we examined the gut mycobiota of three snub‐nosed monkeys: Rhinopithecus roxellana, R. bieti, and R. strykeri using next‐generation amplicon sequencing targeting the fungal internal transcribed spacer. The alpha diversity indexes of gut mycobiota in R. bieti were significantly higher than R. roxellana and R. strykeri, the beta diversity indicated that R. roxellana and R. bieti had more similar feeding habits. Core mycobiota demonstrated commonalities among the three species and potentially associated with feeding habits. Mycobiota displaying significant differences exhibited the respective characteristics of the host, likely associated with the hosts’ living environment. Among them, animal and plant pathogenic fungi and lichen parasites are potential threats to the survival of snub‐nosed monkeys for their pathogenicity to both monkeys and their food plants. Functionally, fungal trophic modes and functional guilds revealed a strong association between gut mycobiota and host diet. We found a higher abundance and more significant correlations with lichen parasitic fungi in R. strykeri than the other two species, indicating potential threats to their foods. Accordingly, this study revealed the basic structures of gut mycobiota of three wild Rhinopithecus species and highlighted the associations between gut mycobiota and their feeding habits and living environments. Furthermore, due to the close connection between fungi and the environment, animals could ingest fungi from their diet; thus, we speculate that gut mycobiota may serve a role in environmental monitoring for wildlife. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, we investigated the fine structure of the proboscis and its associated sensilla in adult Colias erate (Esper, 1805). The results show that the elongated proboscis is structurally similar in both sexes, with external features supporting its division into three distinct regions (zones 1–3). Three types of sensilla, comprising five subtypes, were identified in the proboscis. The uniformly short, aporous sensilla chaetica likely represents an adaptation to reduce friction when the proboscis extends into deep and narrow floral corollas. A single sensillum styloconicum is located at the apex of each galea, consistent with observations in other Colias species. This study provides a morphological basis for understanding the feeding mechanisms of Pieridae. Morphological studies of the proboscis can provide valuable insights into the evolutionary adaptations of Lepidoptera. However, such research is relatively limited for Pieridae, a family that is significant both ecologically and economically. In this study, scanning electron microscopy (SEM) was employed to investigate the proboscis and associated sensilla of adult C. erate, with an emphasis on ultrastructural details and potential sex-specific differences. The proboscis in both sexes exhibits a similar structure, consisting of two elongated maxillary galeae connected by dorsal and ventral legulae. It is divided into three distinct zones based on morphological changes in the dorsal legulae. The outer surface of the proboscis is characterized by spike-like microbumps on transverse ridges, while the inner surface (food canal) is smooth throughout all three zones, with regularly spaced transverse grooves. Three types of sensilla comprising five subtypes were identified: sensilla chaetica (sc), sensilla basiconica (sb1, sb2, and sb3), and sensilla styloconica (ss). The functional implications of these morphological features are also discussed briefly. [ABSTRACT FROM AUTHOR]

Fish are generally classified as herbivorous, carnivorous, omnivorous, or filter-feeders according to feeding habits, including the feeding method and food content. The feeding habits of fish are reflected in their digestive organ, mainly the intestine. The intestine tract is the main site for digestion and nutritional uptake, and it is regarded as a key organ in fish nutrition. Reportedly, fish gut microbiota contributes to digestion and affect gastrointestinal tract development as well as the overall growth of the fish. The disruption of the intestinal microbiota induced by their feeding habit via diet usually affects the digestive functions of the host through disturbance in bacterial digestive enzyme production. Feeding habits determine the feed composition, which shapes the microbial communities in fish. For example, diet has been reported as a dominant cause of variation in the microbiota composition of rainbow trout. In contrast, feeding habit, which is regulated by many factors, including intrinsic and external factors, such as appetite, structure of the digestive tract, and feed palatability, is an important area of research in the intestinal microflora study. The feeding habit of fishes is one of the main factors affecting the differential colonization of fish intestinal flora. For example, the feeding habit increases the colonization of fish intestinal flora in the order omnivorous > herbivorous > carnivorous. It is also known that feeding habits influence intestinal digestion and structure. However, the influence of feeding habit on proximate composition, digestive enzyme secretion, and intestinal histomorphology is currently not well-known in fish. On the contrary, the feeding habit affects the composition and diversity of the intestinal microflora of fish. The composition and diversity of the microbiota in Carassius auratus, Ctenopharyngodon idella, Siniperca chuatsi, and Schizothorax grahami from the same environment have also not previously been studied. The present study aimed to compare and analyze the differences in the composition and diversity of the intestinal microflora of four fish species, investigating the relationship between their feeding habits and intestinal microflora as well. This study collected 12 intestine samples from each of the four fishes with different feeding habits, including omnivorous (C. auratus), herbivorous (C. idella), filter-feeder (S. chuatsi), and carnivorous (S. grahami), from the same pond. The composition and diversity of the microbial communities were determined by using high-throughput sequencing of 16S rRNA. Meanwhile, this study investigated the effects of feeding habits on the composition and diversity of the intestinal microflora of fish and predicted the potential functions of specific microflora with different nutrients. The results showed that the diversity of the intestinal microflora in fish was significantly affected by feeding habit (P < 0.05), such that higher levels occurred in the order omnivorous (C. auratus) > herbivorous (C. idella) > filter-feeder (S. grahami) > carnivorous (S. chuatsi). Proteobacteria and Firmicutes were the common dominant flora among the four fishes, although there were differences at the genera and species levels. For example, Acinetobacter and Bacteroides species were the most dominant flora in S. chuatsi and C. idella, respectively. Function prediction showed that the intestinal tract of S. chuatsi was mainly gram-negative. The disease resistance potential of C. idella was slightly higher than that of the other three fish species. Acinetobacter johnsonii, Acinetobacter lwoffii, and Pseudomonas stutzeri might help the host to digest protein, while Bacteroidetes may help the host to digest cellulose. In conclusion, feeding habit is one of the main factors affecting the differential colonization of fish intestinal flora. Analyzing the correlation between feeding habits and dominant intestinal flora as well as exploring the function of specific flora, could lay a theoretical foundation for studying the microbial effect of fish nutrition metabolism.

Abstract Cichlid fishes in the African Great Lakes have undergone explosive speciation, acquiring markedly varying ecologies and diets. There are multiple lineages of scale-eating cichlids, and their natural history and evolutionary ecology is only partially understood. We examined the feeding habit of Docimodus evelynae, a known scale eater, in Lake Malawi. The stomach contents of young individuals mainly consisted of unknown 1 mm hard, white warts (> 30%). To clarify the origin of these warts, we conducted an X-ray fluorometer analysis, and found they were rich in sulphur but low in silicon and calcium, suggesting they were epidermal tissues. Histological and morphological analyses revealed they were multicellular and cup-shaped. These characteristics matched only those of the pearl organs of the coexisting cyprinid Labeo cylindricus. DNA was extracted from the warts found in the stomach of five D. evelynae individuals, followed by PCR using primers targeting the partial COI gene of L. cylindricus. The resulting sequences exhibited 98% similarity to those of L. cylindricus. Pearl organs, never reported as a primary food for fish, could offer a substantial nutritional source based on calorific calculations. Understanding how this peculiar diet is foraged is essential for full comprehension of the food-web structure in this lake.

The aim of this study was to compare digestive enzymes activity (alkaline proteases and amylase) in four species of Cyprinidae including one herbivorous species, the Caucasian scraper (Capoeta capoeta), and three omnivorous species, common carp (Cyprinus carpio), roach (Rutilus rutilus), and Caspian kutum, (Rutilus frisii kutum). All four species were fed with similar diet. The results showed that the enzyme profile was similar in four species and amylase enzyme activity was higher compared to protease enzymes (trypsin and chymotrypsin). However, there was a significant difference in the activity of these enzymes among the studied species. The highest trypsin and chymotrypsin activities were observed in roach, while common carp had the highest amylase enzyme and digestive somatic index. Therefore, the amylase activity was independent of feeding habit, while protease activity was relatively more dependent on feeding habit. The highest amylase / protease ratio was recorded in common carp which indicates the higher capacity of this species to utilize carbohydrates, therefore cost-effective feed can be used for its commercial production. [ABSTRACT FROM AUTHOR]

Reservoir construction promotes many environmental impacts, including the enhancement of mercury concentrations in fish. The processes that can influence mercury concentrations in fish in Amazonian reservoirs are still little explored in depth, especially when we consider the possible particularities of the ecosystems in question. This study aims to investigate how mercury concentrations in fish could be influenced by the Tucuruí dam, considering possible changes in their feeding and trophic position according to the dam position (up or downstream). Fish were sampled upstream and downstream of the Tucuruí reservoir, and total mercury (THg) and stable isotopes of carbon and nitrogen (δ15N and δ13C) were measured in muscles. We observed three different Hg bioaccumulation patterns influenced by the dam. These differences occurred due to species trophic niche changes corroborated by the isotope analysis. Higher THg concentrations downstream compared to those upstream ones were only observed for Geophagus proximus. On the contrary, Plagioscion squamosissimus, from downstream, presented lower concentrations than upstream ones. The isotopic niche of these two species presented different changes according to the sampled site. THg biomagnification was higher upstream compared to downstream, considering that the regression slope was approximately two times higher upstream versus downstream. THg concentrations in fish were explained by the differences in their feeding habits according to their location in relation to the dam. The difference in THg biomagnification was able to reflect differences in structure of the food web chain in ecosystems under the dam's influence. [ABSTRACT FROM AUTHOR]

The Atlantic bigeye Priacanthus arenatus is among the main target species by small-scale fisheries in the southwestern Atlantic. Due to its importance to small-scale fisheries, information regarding its trophic ecology is essential for the development of sustainable management plans. Using combined stomach content (SCA) and stable isotope analysis (SIA), the current study examined Atlantic bigeye feeding ecology, including evidence for ontogenetic and intra-annual (i.e. seasonal) diet variation. The diet of Atlantic bigeye was comprised of 16 prey species but was dominated by pelagic crustaceans (53.3% in number) and pelagic fish (19.7%), and benthic crustaceans (11.0%). SCA identified diet variation among seasons (higher dissimilarity in Spring vs. Autumn), which is most likely related to the occurrence of intense coastal upwellings. Significant positive relationships between fish size and δ15N and δ13C values indicated an ontogenetic diet and potential habitat shift; broad isotopic niche area in small individuals (size class I: 115–169 mm) narrowed with increasing body size with the highest niche overlap occurring between size class II (170 to 243 mm) and class III (244 to 308 mm). Overall, the combined SCA and SIA approach determined that the Atlantic bigeye's diet is closely connected to the pelagic food web. These data provide an improved understanding of ontogenetic and seasonal variation in Atlantic bigeye predator-prey interactions in the southwestern Atlantic. [ABSTRACT FROM AUTHOR]

Life history characteristics of Watases lanternfish Diaphus watasei from a deep sea fishing ground of the East China Sea were studied. Overall, 452 adult individuals with standard length ranging from 91 to 147 mm were collected in the continental slope during 3 years. The growth pattern and hatching date were inferred from otolith microstructure analysis, and the stomach contents were examined to clarify feeding ecology. Three distinct zones of the otolith microstructure were depicted, the numbers of increments in the central and middle zones of the D. watasei otolith are in the lowest level in myctophid species studied. The maximum number of growth increments indicated a short lifespan of 2 years. The spawning time almost lasted throughout the year, and then two cohorts were separated according to the estimated hatching time. The length–weight relationship revealed a negative allometric pattern and significant difference between the two cohorts, and a significant seasonal difference was also detected in somatic growth pattern. A piscivorous habit dominated by Maurolicus muelleri was revealed across sampling seasons and standard length groups. Overall, D. watasei show distinct life history characteristics compared to coinhabiting myctophids, and such characteristics could reduce interspecific competition. [ABSTRACT FROM AUTHOR]

Amphisbaenians usually have a diet composed of a wide variety of small arthropods, with some species being more selective in their feeding and others considered more generalist. Using only specimens deposited in scientific collections, the diet composition of Amphisbaena alba Linnaeus, 1758, Amphisbaena pretrei Duméril and Bibron, 1839, and Amphisbaena vermicularis Wagler, 1824 from the Northeast region of Brazil was analyzed. Except for individuals of A. alba, due to the small sample size, we also investigated the possible intersexual difference in the volume, length, and number of prey in the diet of amphisbaenians and the possible relationship between prey volume and body size (snout–vent length) of individuals was analyzed. The diet of worm-lizard in general was composed of termites, cockroaches, ants, and beetle larvae, and no intersexual differences were found in the size, length, and number of consumed prey. The body size of A. pretrei and A. vermicularis showed no relationship with the volume of prey consumed. Amphisbaenians presented a characteristic diet of opportunistic generalist predators, with several food categories in the composition of their diets, indicating that the studied species feed according to the availability and abundance of prey in the environment. [ABSTRACT FROM AUTHOR]

The article presents a comprehensive assessment of avian diversity in relation to water parameters within Narsinh Mehta Lake on the middle outskirts of Junagadh in Gujarat, India. Topics include migratory status of avifauna, list of birds recorded from Narsinh Mehta Lake, and water parameters of Narsinh Mehta Lake.

Research on the occurrence of microplastics in invertebrates of the Thoothukudi region is limited. Capitellids are non-selective suspension feeders and are usually used as bioindicator of water pollution. Hence, an investigation was carried out to identify the microplastic occurrence in the capitellids (Capitella capitata) (Fabricius, 1780) collected from the Vellapatti and Spic Nagar sites of the Thoothukudi region. Result from this investigation showed the occurrence of 0.21 ± 0.17 items/indiv and a mean abundance of 13.33% in Thoothukudi coast. The mean microplastic abundance in the capitellids was significantly higher in the Spic Nagar (0.26 ± 0.19 MPs/indiv), probably due to the dumping of plastic waste, fishing and recreational activities. However, no significant difference was observed between seasons. Only fragments (Vellapatti 66.66% and Spic Nagar 33.33%) and fibre-shaped microplastics (Vellapatti 50% and Spic Nagar 50%) were identified. The size and colour of the microplastics dominant in both sites were 1–2 mm (Vellapatti 77.77% and Spic Nagar 75%) and blue (Vellapatti 88.88% and Spic Nagar 87.5%), respectively. The results of Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) analysis revealed the presence of polyethylene (PE) and polypropylene (PP) polymers in the capitellids. PE polymer is one of the most common sources of microplastics contamination globally and it is also frequently found in the coastal waters of Thoothukudi. This accounted for the high occurrence of PE polymers in the capitellids with the occurrence rate of 77% in Vellapatti and 58.52% in Spic Nagar. The present study provides baseline data on the occurrence, characterization (shapes, sizes and colours) and qualitative analysis of the microplastics in the capitellids, and their presence was influenced by their non-selective feeding habits. Further, future studies have to be conducted to identify the levels of microplastics in different polychaetes and other invertebrates to better understand the effects of microplastic pollution in invertebrate communities. [ABSTRACT FROM AUTHOR]

This article explores the coexistence mechanisms of different species of predaceous diving beetle larvae in Japanese paddy fields. The study investigates the feeding habits, microhabitat use, and phenology of four diving beetle species through field observations. The researchers found that the larvae exhibited interspecific differences in feeding habits, microhabitat use, and phenology, which allowed them to coexist. The study suggests that behavioral differences and phenological variations play important roles in reducing resource competition among the diving beetle larvae. Further research is needed to confirm these findings and explore the functional morphology of the larvae. [Extracted from the article]

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The present work attempted to provide a comprehensive description of the morphoanatomical, histological, and ultrastructural characteristics of the tongue in the desert hedgehog (Paraechinus aethiopicus), and to correlate lingual modifications to the feeding lifestyle. Five adult male hedgehogs were utilized in our investigation. The macroscopic observations revealed elongated, with a moderately pointed apex, tongue and the tongue dorsum lacks both lingual prominence and median sulcus. The main subdivisions of the tongue are radix linguae (root), corpus linguae (body), and apex linguae (apex). The tongue dorsum carries two types of mechanical (conical and filiform) and gustatory (fungiform and circumvallate) papillae. The lingual apex is characterized by the existence of a unique encapsulated muscular structure. Additionally, the lingual glands were interposed between the muscular strands and no lingual glands were detected on the lingual apex. The dorsal surface of the lingual apex exhibited the highest level of keratinization as revealed by histochemical staining while the root showed moderate staining. The topography of the tongue was investigated by scanning electron microscopy (SEM). The obtained results are important to provide basic knowledge that can contribute to better understanding of the nourishment, feeding habits and behavior in this species. Furthermore, the addition of the newly investigated species may help us to determine the evolutionary relationships among species. Highlights: The present study introduces the first description of the anatomical and microanatomical characteristics and tongue modifications in accordance with feeding preferences in the desert hedgehog (Paraechinus aethiopicus).P. aethiopicus tongue dorsum lacks lingual prominence and median sulcus and mechanical and gustatory papillae are distributed on the tongue dorsum.The tongue characteristics seem to be conserved among other members of the family Erinaceidae as the feeding habits are the same, but there are some species‐specific differences. [ABSTRACT FROM AUTHOR]

Abstract Upwellings are important oceanographic processes that induce several changes in marine ecosystems, including in the benthic-pelagic coupling (BPC) that plays a major role in coastal areas. However, there is little available information about the possible effects of coastal upwellings on the trophic role of predators and in the BPC. Thus, here we investigate possible seasonal and ontogenetic changes in the trophic interaction of a demersal predator, the Brazilian flathead Percophis brasiliensis, from an upwelling ecosystem. Sampling was carried out for one year during two coastal upwelling events. Based on stomach content analysis (SCA) were recorded seasonal diet shifts, probably driven by coastal upwellings, leading to an increase in pelagic prey and changing the trophic coupling pathways. Stable isotope analysis revealed that isotopic niche decreased with the body size, as well as the values of the Levins’ index. Also, significant, and positive relationships were observed between δ13C and δ15N versus total length. Our results showed that the demersal predator has a relevant trophic role in the BPC which is probably influenced by coastal upwellings.

Monochamus saltuarius Gebler (Coleoptera, Cerambycidae) serves as the primary carrier of Bursaphelenchus xylophilus (Steiner & Buhrer) (Aphelenchida, Aphelenchoididae) in the middle-temperate zone of China. Pine wilt disease caused by B. xylophilus leads to serious losses to pine forestry around the world. It is necessary to study the biological control of M. saltuarius to effectively prevent the further spread of B. xylophilus. To explore the insect resources that act as natural enemies of M. saltuarius, investigations were conducted on natural enemy insects by splitting Pinus koraiensis Siebold & Zucc (Pinales, Pinaceae) damaged by M. saltuarius and dissecting their trunks in Yingpan Village, Fushun County, Fushun City, Liaoning Province, China, in 2023. A larva of Inocellia (Amurinocellia) calida (H. Aspöck & U. Aspöck) (Raphidioptera, Inocelliidae) was discovered in the trunk of an infested P. koraiensis. Additionally, the feeding habits of I. calida were preliminarily examined under indoor conditions and a description of its morphological characteristics was provided. When placed in an indoor environment, the I. calida larva began pupating after a period of 21 days, during which time it consumed and attacked a total of 23 M. saltuarius larvae. Ultimately, after a pupal period of ten days, the I. calida larva emerged successfully as an adult. This discovery marks the first recorded presence of I. calida in Liaoning Province and the first documentation of I. calida in China, serving as a natural predatory enemy of M. saltuarius. [ABSTRACT FROM AUTHOR]

Macrognathus is a genus of eel-like fish of the family Mastacembelidae of the order Synbranchiformes. The majority of South and Southeast Asia is home to these fish. The major food category of this genus is crustaceans (such as prawns) and aquatic insects (Chaoborus spp.), while juveniles mostly consume annelids (such as earthworms). According to various studies, it was found that the male: female ratio of Macrognathus sp is roughly 1:1. Macrognathus exhibit a wide range of fecundity, and the number of ova or eggs laid by a single female depends on several variables, including size, age, species, and the ecological habitats of the fish, including the availability of food. The fecundity of these fishes is found to be high when the fish were breeding, which occurred from May through August. The average ovarian diameter of M. pancalus has been found to increase every month. In some studies, lentic habitats showed higher ova diameter than lotic habitats for Macrognathus sp. For Macrognathus sp. the males matured at lengths of 10 to 11 cm and females at lengths of 11 to 12 cm on the other hand M. aral was found to be matured at an average of 12.05 cm for males and 16.05 cm for females. [ABSTRACT FROM AUTHOR]

Inter-annual variation in the feeding habits and food sources of Japanese sardine and mackerel at age-0 and age-1+ caught in the Kuroshio-Oyashio transition zone of the Western North Pacific were investigated based on analyses of bulk stable isotopes (δ13C, δ15N) and amino acid nitrogen isotopes (δ15NAA). Differences in δ13C and δ15N between Japanese sardine and mackerel were small for age-0, and inter-annual variation trends were similar, suggesting they depend on similar food sources in the same food web at this age. In contrast, inter-annual variation in δ13C and δ15N were significantly different between both species at age-1+, and both δ15N of phenylalanine (δ15NPhe: an indicator of nitrogen source) and trophic position estimated from δ15NAA (TPAA) were higher in mackerel, suggesting that the two species depend on distinct food webs as they age. Inter-annual variations in δ15NPhe were considered to have different causes for the two species; differences in food web structure due to the degree of southward intrusion of the Oyashio Current for Japanese sardine, compared to a shift in migration area and depth for mackerel. Furthermore, competition for food due to the recent increases in the population densities of both fishes appeared to be reflected in increased TPAA of mackerel. Although they are caught in the same region, the mechanism of variation in food sources differs because of differences in migration area, depth, and feeding habits. Differences in the feeding habits of Japanese sardine and mackerel may affect trophic status and spawning characteristics, potentially leading to different shifts in stock abundances. [ABSTRACT FROM AUTHOR]

Caucasian scraper (Capoeta capoeta) is one of the native fish of Iran, in the southern basin of the Caspian Sea and Sang Siah Lake of Kurdistan. To study the reproductive cycle of this fish, sampling by gill net was done monthly from June 2018 to May 2019. The biometry of specimen in the Lab was done and sexuality, maturity stages and gonad growth index (GSI) were recorded. The sex ratio of specimen of 1.5 to 1 (female to male), the total length of males 29.3 ± 2.1 cm and the total length of females 32±2.3 cm were recorded. The average weight of males and females were 284.6±50.9 and 378.2±79.3 g, respectively. Also, examining the changes in sexual maturity index (GSI), both sexes had the highest GSI in July. The average relative length of the intestine in this species (6.8±1.29) indicated the herbivorous food regime. The average percentage of empty stomach in the whole period was estimated to be 11.7, which shows that this species is a gluttonous. Also, the highest average amount of gastric index (GI) was estimated in spring. The results of this study showed that July is the peak of sexual maturity and reproduction of this species. Investigation the results of its food habits and preferences in the digestive system showed that this fish prefers algae than other food resources. Due to the high growth and reproduction and also food regime, this fish can be introduced as an economic species to culture and sport fishing in the reservoirs. [ABSTRACT FROM AUTHOR]

Dytiscus sharpi is defined as "Critically Endangered" in the Red List of Japan and designated as a "nationally endangered species of wild fauna and flora" of the Japanese "Conservation of Endangered Species of Wild Fauna and Flora" Act. In previous studies, tadpoles of Red List species (Rana ornativentris) were collected, and approximately 300 tadpoles were needed to raise one D. sharpi adult. A rearing experiment was performed to identify alternative prey for D. sharpi larvae. Larvae were reared on cultivable prey (Asellus hilgendorfii, goldfish, and crickets), and the quality of alternative prey was compared to that of tadpoles based on three criteria: adult size, survival rate, and development speed. Adult size, survival rate, and development speed values showed that alternative prey, i.e., A. hilgendorfii, goldfish, and crickets, were of adequate quality as larval prey according to all monitored parameters when compared to tadpoles. Dytiscus sharpi larvae can be raised using only cultivable prey, and multiple choices are available. The elimination of the need to overcollect endangered tadpoles from the field by using alternative prey for rearing will contribute to the conservation of both D. sharpi and R. ornativentris. This result would make ex-situ conservation of D. sharpi sustainable. Implications for insect conservation: Furthering the ex-situ conservation of D. sharpi by using A. hilgendorfii, goldfish, and crickets as alternative prey, will contribute to the conservation of not only D. sharpi but also of the tadpoles of R. ornativentris. [ABSTRACT FROM AUTHOR]

The socio-economic benefits derived from impounding rivers are extremely important but the ecological imbalances that are usually created in the process can be devastating. It is therefore imperative to understand some aspects of the biology of fishes before the impoundment of a river. This study was conducted to assess the lengthweight relationship, condition factor, feeding, and reproductive ecology of fish species with high local market value. Biometric measurements were obtained from monthly samples of fish at two sites. Specimens were transported to the laboratory for gut and gonad analyses. Auchenoglanis occidentalis, Marcussenius senegalensis and Heterobranchus bidorsalis were the most preferred fish species. All three fish species recorded ‘b’ values less than 3 which implies they exhibited a negative allometric growth. Their condition factors (K) indicated they were in good health since K values were greater than 1. A. occidentalis and H. bidorsalis demonstrated a feeding habit comparable to that of an omnivore, whilst M. senegalensis presented a feeding habit that implied it was an invertivore. M. senegalensis registered the uppermost mean gonado-somatic index (GSI) (2.14 ± 0.83) whereas the highest mean fecundity (495 ± 450.96) was noted in A. occidentalis. This study contributed bio-ecological baseline information about the ichthyofauna prior to the damming of the reservoir in the Pwalugu area of the White Volta. [ABSTRACT FROM AUTHOR]

Objective: The study investigated the gut content and recorded morphometric and hematological parameters in the Eurasian collared dove (Streptopelia decaocto). Materials and Methods: 24 samples of healthy birds (12 from each sex) were collected from different wetlands in Punjab, Pakistan, from December 2022 until February 2023. Birds were cap¬tured live for blood samples, morphometric, and gut analyses. Results: The current study revealed that mensural measurements showed no significant differences in all parameters except tail length, which was significantly longer in males (14.59 ± 0.30) compared to females (12.88 ± 0.43). Hematological parameters were hemoglobin, 23.95 gm/dl; red blood cells, 3.97 × 106/μl; white blood cells, 429.9.67 × 103/μl; hematocrit, 72.14%; mean cor¬puscular volume, 183.24 FL; mean corpuscular hemoglobin, 61.70 pg; mean corpuscular hemo¬globin concentration, 32.37 pg; platelets, 7.01/μl; and red cell distribution width, 110.86/μl. The percentages of neutrophils, lymphocytes, monocytes, and eosinophils were 71.33%, 23.03%, 3.30%, and 1.43%, respectively. The gut content of the Eurasian collared dove mainly consisted of rice, wheat, corn, and millet seeds. Some stony materials were also present. Conclusion: Our study concluded that male and female Eurasian collared doves are alike in biometrics (except tail length) and hematological profiles. Gut content and weight were also similar. Males were slightly larger than females. The gut content showed that the Eurasian collared dove mainly feeds on rice, wheat, corn, and millet seeds. In this study, hematological parameters were also studied. [J Adv Vet Anim Res 2023; 10(2.000): 244-248]

Background: Spotted redshank (Tringa erythropus) is a shorebird. Morphometric and feeding studies on birds were very important to understanding geographic distribution and it plays a key role in conservation of particular species. Objective: The present research was conducted to investigate hematological variation, food preference, and morphometric profiles of the spotted redshank (Tringa erythropus). Methods: Twenty samples (n = 10 for each sex) were collected from different wetlands. Blood was collected for hematological analysis and measuring tape was used for mensural profiles. For gut analysis, stomach was removed. Results: Results showed that body weight of males was heavier than body weight of females. All parameters, like body weight, body length, total wing span, primary wing, tarsal, meta-tarsal, body circumference, and tail length had greater values in males as compared with females, except head size. The male head size was smaller than the female head size. A significant difference was recorded in all blood parameters except hemoglobin and monocytes between the both sexes. Analysis of gut showed that the spotted redshank mostly feeds on Ceratopogonidae and larvae of Chironomidae. Conclusion: It is concluded that a significant difference was observed in morphometric profiles and hematological analysis and food preference between male and female spotted redshank (Tringa erythropus).

The socio-economic benefits derived from impounding rivers are extremely important but the ecological imbalances that are usually created in the process can be devastating. It is therefore imperative to understand some aspects of the biology of fishes before the impoundment of a river. This study was conducted to assess the length-weight relationship, condition factor, feeding, and reproductive ecology of fish species with high local market value. Biometric measurements were obtained from monthly samples of fish at two sites. Specimens were transported to the laboratory for gut and gonad analyses. Auchenoglanis occidentalis, Marcussenius senegalensis and Heterobranchus bidorsalis were the most preferred fish species. All three fish species recorded ‘b’ values less than 3 which implies they exhibited a negative allometric growth. Their condition factors (K) indicated they were in good health since K values were greater than 1. A. occidentalis and H. bidorsalis demonstrated a feeding habit comparable to that of an omnivore, whilst M. senegalensis presented a feeding habit that implied it was an invertivore. M. senegalensis registered the uppermost mean gonado-somatic index (GSI) (2.14 ± 0.83) whereas the highest mean fecundity (495 ± 450.96) was noted in A. occidentalis. This study contributed bio-ecological baseline information about the ichthyofauna prior to the damming of the reservoir in the Pwalugu area of the White Volta.

Microbial symbionts play important roles for zooplankton by promoting nutrition, growth, and reproduction. We report bacterial communities from bodies and feces of three zooplankton taxa (Eodiaptomus japonicus, Daphnia pulicaria, Cyclopoida spp.) from Lake Biwa using meta-barcoding analysis targeting the prokaryote-specific V4 region of 16S rDNA. A total of 669 bacterial OTUs were generated. Bacteria associated with the body and feces of E. japonicus were most divergent. The bacterial compositions of the bodies and feces in all three host taxa differed significantly. The bacterial phyla in the zooplankton bodies and feces were dominated by Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. At lower taxonomic levels, the bacteria of bodies (in particular) and feces differed among zooplankton taxa. Prevalent bacteria of D. pulicaria and Cyclopoida spp. bodies were Aeromonadales (Gammaproteobacteria), and those of E. japonicus were dominated by Burkholderiales (Betaproteobacteria). Aeromonadaceae was the most dominant bacterial family in zooplankton bodies, while Pelagibacteraceae was dominant in feces. The bacterial communities present in the feces were similar among the taxa but differed from those found in the bodies of the animals themselves, implying that the feces contained transient bacteria passing through the digestive system. The bacterial composition associated with the zooplankton bodies may be related to the host's feeding habits, habitat selection, and behavior. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Oreochromis niloticus is the most ecologically and economically important fish in tropical and sub-tropical aquatic systems. Recently, due to sever anthropogenic stressors, hydrological variations and infestations of invasive alien species in Ethiopian water bodies, fish community structure and ecosystem of Lake Tana is changing alarmingly. So far, there is paucity of information on the morphometric relations and diet composition of O. niloticus in Lake Tana, gulf of Gorgora. A total of 309 fish samples were collected and their total length (TL), standard length (SL) and total weight (TW) were measured to determine morphometric relations; and gut contents were examined to identify most important food item in the diet of the fish. Results indicated that, the relation between TL and SL was significant (p < 0.001) and linear (SL = 0.942TL-2.41) while the relation between TL and TW was curvilinear (TW = 0.014 TL2.8) indicating allometric growth. Among the total guts scrutinized, 53 (17.3%) of them were empty and the remaining 256 (82.7%) were non-empty. Phytoplankton constituted the largest bulk and occurred in 77% of the guts examined and volumetrically accounted 44.3%. Detritus and zooplankton had an intermediate importance by occurring 60.2% and 63.3% of all guts scrutinized and constituted about 25.6% and 15.5% of the total volume respectively. Contributions of macrophytes, insects, nematodes and unidentified food items were relatively low in their importance. Ontogenetic dietary shift was observed in the diet indicating an omnivorous feeding habit of the adult fish.

The Beibu Gulf is the fourth largest Chinese fishing ground, with rich fishery resources and a significant role in marine fishery production. The feeding ecology of fish is important to explain the structure and function of marine ecosystems. As one of the most important fish species in the Beibu Gulf, Nemipterus japonicus plays an essential role in energy flow and other aspects of the marine ecosystem. Understanding its feeding ecology could provide a basic theoretical basis for the rational utilization and protection of this resource. A total of 248 N. japonicus specimens were collected from Beibu Gulf from January to April and August to December in 2018. The food content composition, feeding intensity, and feeding niche of N. japonicus were analyzed using stomach contents to reflect feeding habits. Combined with carbon and nitrogen stable isotopes, the food source and trophic structure characteristics were analyzed, the trophic level was determined, and the feeding ecology of N. japonicus in the Beibu Gulf was discussed. The stomach content analysis revealed that N. japonicus is a broad-feeding benthic carnivore, which feeds on a large number of species, including eight prey groups, including fish, shrimp, and crab, among which fish and shrimp are the dominant food groups, with a relative importance index of 92.92%. The proportion of food species varied with the season and growth. Fish were an important prey group across all seasons. Moreover, N. japonicus preyed on shrimp in spring, crab in summer, shrimp and polychaetes in autumn, and shrimp and sipunculoidea in winter. With an increase in body length, the feeding habits of N. japonicus gradually change from primarily feeding on shrimp and fish to mainly feeding on fish, and the body length node of feeding transition was approximately 130 mm. There were clear seasonal variations in feeding intensity, with the highest intensity in autumn, followed by that in spring and summer, and the lowest in winter. N. japonicus had a high prey diversity; the Shannon-Wiener diversity index (H') was 1.77, and the Pielou evenness index (J') was 0.64. From spring to winter, the H' and J' values tended to increase and then decrease, and the highest value occurred in autumn, which meant that the feeding niche was the highest in autumn. The number of prey species increased with individual growth, and H' and J' showed an increasing trend with body length. The group with a body length ≥ 160 mm had the largest niche width, which suggested that the food diversity increased with individual growth, and the diet changed to broad-feeding.Based on stable isotope analysis, δ13C was positively correlated with the body length of N. japonicus (P < 0.05), indicating that the trophic source changed with growth. The span of the δ13C (CR) range was 2.86%, indicating extensive basic food sources. The span of the δ15N (NR) range was 4.23%, and the trophic span was more than one trophic level, indicating considerable differences in feeding among individuals. A significant positive correlation was found between body length and δ15N (P < 0.01), which indicated that the trophic level increased with an increasing body length. The trophic level of N. japonicus ranged from 3.21 to 4.46, with an average value of 3.97, indicating that N. japonicus species were middle-high carnivorous animals, and were at a high trophic level in the fish food web of the Beibu Gulf. The trophic level obtained in this study is higher than that obtained in other studies, which may be related to the changes in the composition of the prey, N. japonicus has shifted from feeding mainly on the low trophic level (crustaceans) to the high trophic levels (fish).In terms of trophic structure, the CR value of N. japonicus in the Beibu Gulf in spring and winter was lower than that in summer and autumn, indicating that the basic food source diversity in spring and winter is lower than that in summer and autumn, however, there are fewer prey species in summer, which might be caused by the feeding preference of N. japonicus. Simultaneously, the NR values in spring and summer were greater than those in summer and autumn, indicating that the span of the main trophic sources in the feed was higher than that in summer and autumn, consistent with the seasonal variation of dominant prey. Although the standard ellipse area (SEA) overlaps to different degrees among seasons, the total niche (TA) had clear seasonal differences, signifying that there were certain similarities and specific differences in prey resource utilization, which is beneficial for alleviating the seasonal pressure on the dominant prey. Furthermore, the CR value in different body length groups of N. japonicus showed an overall upward trend with individual growth, indicating that the food source diversity increased with growth. The NR value decreased when body length was greater than 130 mm, which indicates that the average trophic level of the population was concentrated when individuals grew to a certain stage. The SEA overlap rate was higher among length groups, implying that the trophic source components were similar at different growth stages; however, TA tended to increase and then decrease with body length, which may reduce food competition within species by niche differentiation.

The changes in the expression of genes related to digestion and metabolism may be various in different dietary mammals from juvenile to adult, especially, the giant panda (Ailuropoda melanoleuca) and red panda (Ailurus fulgens), which were once carnivores but have shifted to being specialized bamboo eaters, are unique features of their changes are more unclear. To elucidate the changing patterns of gene expression related to digestion and metabolism from juvenile to adult in different dietary mammals, we performed transcriptome analysis of the liver or pancreas in giant and red pandas, herbivorous rabbits (Oryctolagus cuniculus) and macaques (Macaca mulatta), carnivorous ferrets (Mustela putorius furo), and omnivorous mice (Mus musculus) from juvenile to adult. During the transition from juvenile to adulthood, giant and red pandas, as well as rabbits and macaques, show significant upregulation of key genes for carbohydrate metabolism, such as starch hydrolysis and sucrose metabolism, and unsaturated fatty acid metabolism, such as linoleic acid, while there is no significant difference in the expression of key genes for fatty acid ß-oxidation. A large number of amino acid metabolism related genes were upregulated in adult rabbits and macaques compared to juveniles. While adult giant and red pandas mainly showed upregulation of key genes for arginine synthesis and downregulation of key genes for arginine and lysine degradation. In adult stages, mouse had significantly higher expression patterns in key genes for starch hydrolysis and sucrose metabolism, as well as lipid and protein metabolism. In contrast to general expectations, genes related to lipid, amino acid and protein metabolism were significantly higher expressed in adult group of ferrets, which may be related to their high metabolic levels. Our study elucidates the pattern of changes in the expression of genes related to digestion and metabolism from juvenile to adult in different dietary mammals, with giant and red pandas showing adaptations associated with specific nutritional limitations of bamboo. [ABSTRACT FROM AUTHOR]

Objective: The study investigated the gut content and recorded morphometric and hematological parameters in the Eurasian collared dove (Streptopelia decaocto). Materials and Methods: 24 samples of healthy birds (12 from each sex) were collected from different wetlands in Punjab, Pakistan, from December 2022 until February 2023. Birds were captured live for blood samples, morphometric, and gut analyses. Results: The current study revealed that mensural measurements showed no significant differences in all parameters except tail length, which was significantly longer in males (14.59 ± 0.30) compared to females (12.88 ± 0.43). Hematological parameters were hemoglobin, 23.95 gm/dl; red blood cells, 3.97 × 106 /µl; white blood cells, 429.9.67 × 10³ /µl; hematocrit, 72.14%; mean corpuscular volume, 183.24 FL; mean corpuscular hemoglobin, 61.70 pg; mean corpuscular hemoglobin concentration, 32.37 pg; platelets, 7.01/µl; and red cell distribution width, 110.86/µl. The percentages of neutrophils, lymphocytes, monocytes, and eosinophils were 71.33%, 23.03%, 3.30%, and 1.43%, respectively. The gut content of the Eurasian collared dove mainly consisted of rice, wheat, corn, and millet seeds. Some stony materials were also present. Conclusion: Our study concluded that male and female Eurasian collared doves are alike in biometrics (except tail length) and hematological profiles. Gut content and weight were also similar. Males were slightly larger than females. The gut content showed that the Eurasian collared dove mainly feeds on rice, wheat, corn, and millet seeds. In this study, hematological parameters were also studied. [ABSTRACT FROM AUTHOR]

Nandus nandus (Hamilton, 1822) is a small indigenous species (SIS) and commercially important food fish found in Bangladesh, India, Nepal, Pakistan, Myanmar, and Thailand. Concerns have arisen due to the gradual decline in its abundance, reflected by poor catches and limited availability of this species in local markets. Habitat loss and overexploitation pose significant threats to this species, leading to its classification as near threatened by the IUCN Bangladesh. Despite the absence of dedicated conservation efforts for N. nandus in Indian subcontinent, this study aims to investigate the species' biology, ecology, distribution within the country and globally, as well as its threats, conservation strategies, and research needs. Additionally, a proposed conservation framework for this near-threatened species is presented, which can be adapted for implementation in other nations facing similar challenges.

The present dataset provides information on the abundance of microplastics (MPs) in relation to different feeding habits of the four mangrove brachyuran crab species namely, Parasesarma eumolpe, Austruca annulipes, Metaplax elegans and Scylla olivacea at Setiu Wetlands in Peninsular Malaysia. Three sites namely, Pulau Layat (upstream, close to the core mangrove zone), Kampung Pengkalan Gelap (midstream, close to the settlements), and Pulau Sutung (downstream, close to the shifted river mouth) were chosen for the sample collection (through hand catch method and traps) in both the dry (Feb-Mar 2021) and the wet (Dec 2021 - Jan 2022) seasons. The cardiac stomach of each crab was dissected, digested in potassium hydroxide and then filtered through a 1.6 µm pore size glass fibre filter using the vacuum pump. The abundance, type and colour of MPs per crab individual were determined under a stereomicroscope (Carl Zeiss Stemi 508, China) attached to the digital camera (Axiocam 208 colour). The general abundance of MPs was found in the order of carnivorous S. olivacea > microphytobenthos feeder A. annulipes > herbivorous P. eumolpe > detritivorous M. elegans. The data also reveal morphometric measurements such as body weight, gut weight, carapace width and carapace length of the crab specimens. The information given in this article is useful for study replications and scientific comparisons, especially with brachyuran crabs and other organisms with similar feeding guilds, in the mangroves of Malaysia and elsewhere.

Microplastics pollute the marine environment and pose a greater risk to marine organisms. The microplastics were observed in the guts of the 12 species, which varied from 0.00 to 1.80 ± 1.19 particles /individual. Most of the microplastics were fibre shaped, 0.5–1 mm sized, blue-coloured, and polyethylene polymers. The abundance of the microplastics was higher for benthic species (0.66 ± 0.13 particles/ individual) than the pelagic species (0.53 ± 0.11 particles/individual), with no significant difference (p > 0.05). According to their feeding habits and trophic level, significantly the microplastics were abundant in the herbivores (1.23 ± 0.61 particles/individual) and quaternary consumers (0.76 ± 0.16 particles/individual), respectively. The present study suggests that microplastic ingestion in commercially important species was influenced by their feeding habits irrespective of their habitat and length and weight. In addition to this, biomagnification of the microplastics (Trophic Magnification Factor, TMF = 1.02) was also observed in the commercially important species with increasing trophic level. This further indicates that the trophic level can serve as the pathway for the transfer of microplastics from lower trophic level organisms to higher trophic level organisms. The present study concludes that the occurrence of biomagnification of microplastics and the pollutants absorbed by them might harm the commercially important species from the Thoothukudi region. [ABSTRACT FROM AUTHOR]

The leeches Whitmania pigra and Hirudo nipponia live in similar environments but have different feeding habits. At present, there are few studies of the foraging mechanism of leeches with different feeding habits. In this study, we first used maze tests to show that these two species of leeches could locate and distinguish their prey through chemosensory activity without mechanical stimulation. However, the two leech species have different foraging behaviors: Individuals of W. pigra move slowly and repeatedly adjust direction through probing and crawling to detect the location of prey (snails), whereas individuals of H. nipponia move quickly, and after determining the location of food (porcine blood), they quickly swim or crawl to the vicinity of their prey. Scanning electron microscopy (SEM) revealed that there are two types of sensory cilia and pore structures related to mucus secretion in the heads of both leeches. There are two differently sized types of chemoreceptors on the dorsal lip in W. pigra, which may have different functions during foraging, whereas in H. nipponia there is only one type of chemoreceptor, which is small. We detected the chemical components in the natural food of these two leech species by UHPLC–MS. There were 934 metabolites in the body fluid of snails and 751 metabolites in porcine serum; five metabolites unique to the body fluid of snails and to porcine serum were screened as candidate feeding attractants. Of these metabolites, betaine and arginine effectively attracted individuals of W. pigra and H. nipponia, respectively. In summary, leeches with different feeding habits use chemoreceptors to sense external chemical signals when foraging, and there are significant differences between species in foraging behavior, chemoreceptors, and attractants. [ABSTRACT FROM AUTHOR]

Most ecological studies of chiropteran diets report that phyllostomid bats of the subfamilies Stenodermatinae, Carolliinae, and Rhinophyllinae feed principally on fruits. Nevertheless, under certain circumstances, some species can consume a considerable amount of other food resources (nectar/pollen, leaves, and arthropods) as dietary complements to meet their nutritional requirements. We found a relatively high consumption of arthropods by frugivorous phyllostomids as a result of an analysis of feces from a bat community in a lowland forest of northeastern Peru during the dry season. A total of 290 bats (30 species) were captured, from which 188 were frugivorous phyllostomids (13 species). Fecal samples with arthropod remnants were obtained from bats of the genera Artibeus, Carollia, Sturnira, and Rhinophylla, which corresponded to 45% of the samples obtained from the complete assemblage of frugivorous phyllostomids. For three Artibeus species (A. lituratus, A. obscurus, and A. planirostris), arthropods were found in half or more of their fecal samples. This relatively high consumption of arthropods did not significantly differ between male and female frugivorous bats. Findings could be related to a low availability of fruits and high availability of arthropods during the study period. [ABSTRACT FROM AUTHOR]

The current study is focused on a comprehensive stock assessment of Gudusia chapra to assess the stock status along with feeding habits, essential minerals content and risk to human health from exposure to heavy metals. A total of 723 specimens from the Bukvora Baor, Bangladesh were used to estimate the total body length (TL) and body weight (W) which ranged from 5.5 to 14.5 cm and 1.62–26.45 g, respectively. The estimated asymptotic length (L∞) of this species (15.38) was in comparison with average length at 10 cm from 723 specimens along with the rate of 0.70 yr−1 for approaching to asymptotic length. The obtained growth performance index (φ) 2.2 indicates that this species is not economically feasible to bring under aquaculture. At an average annual water surface temperature of 28 °C, natural mortality, 1.71yr−1 indicating good ecological suitability of Bukvora oxbow lake (Baor). The estimated current exploitation ratio (0.24) reflected under-exploitation status with total instantaneous mortality (2.25 years−1) and fishing mortality (0.55 years−1). The recruitment pattern of this species was observed across the year, with main peak occurring during the period of April to May. The estimated total steady state biomass (3.91 metric ton) and MSY (4.40 metric ton) based on length-structured virtual population analysis (VPA) length-structured virtual population analysis (VPA) through FiSAT II schedule indicating the sustainable production of this species. The obtained values of proximate compositions (% of protein, fat, Moisture, ash) showed no significant variations during different seasons throughout the year. The monthly measurements of GaSI showed significant alterations (p

ABSTRACT Orthopterans are an important component of the food chain. The species belonging to the order Orthoptera are herbivores or predators, and several behave as opportunistic predators. However, their predatory habits are not well understood. Here we report the predation of a Chactopsis sp. scorpion by a Hyperomerus sp. katydid in a fragment of terra firme forest in the western Brazilian Amazon. The specimens were found on a 60-cm tall bush. The scorpion showed spasmodic motions of the metasoma while it was being devoured by the katydid. This is the first report of a predator-prey interaction between an orthopteran and a scorpion in the Amazon biome. We believe that records of this type are important to allow a better understanding of predator-prey interactions in tropical invertebrate communities.

In this study, we aimed to investigate the presence of an alteration in the feeding ecology of fish after the deployment of anti-trawling reefs at the Punta Tramontana site (Sardinia, Italy). To achieve this aim, we examined prey in the stomach contents of two target species of fish: Diplodus annularis and Mullus surmuletus. The samples were obtained from fishing activities carried out over one year from June 2017 to October 2018 at two impact sites, selected by the presence of artificial reefs, and two control sites. The results showed that installing these artificial devices increased the food spectrum availability of the target species and induced two different ecological feeding behaviors, probably derived from their different ecologies. D. annularis changed its alimentary strategy from generalist at control sites to specialist at impact sites, focusing its diet on the crustacean Gnathia maxillaris. Mullus surmuletus was not affected by the presence of the barriers, which constitute an additional site where the fish feed during their foraging activities. In conclusion, these anti-trawling reefs, in addition to the purpose for which they are designed (in this case, avoiding illegal trawling), did not produce any negative environmental impact on surrounding marine biota. [ABSTRACT FROM AUTHOR]

The stomach contents of 30 male and 43 female (age < 3 years; 74–236 cm total length) juvenile great hammerhead sharks (Sphyrna mokarran (Rüppell, 1837)) obtained from commercial fisheries operating in Saudi Arabian waters of the Arabian Gulf were analyzed for the first time. After exclusion of parasites and abiotics, a total of 31 prey items, including the remains of cephalopods, fish, crustaceans, and bivalve mollusks, were identified in the stomachs of 59 great hammerheads. Based on the index of relative importance, teleosts were their main prey, and Platycephalus indicus (Linnaeus, 1758) was the most important prey at the species level. Significant age-related dietary differences were noted (F = 1.57, p = 0.026), indicating that the prey of the hammerheads aged 0–3 years shifted from Platycephalidae to Myliobatidae. Levin's niche overlap index was low (0.05–0.21), indicating that <3-year-old juvenile great hammerheads are specialized predators. The estimated trophic level was 4.40–5.01 (mean ± SD, 4.66 ± 0.45), indicating that the great hammerhead is a tertiary consumer. [ABSTRACT FROM AUTHOR]

Simple Summary: The mangrove ecosystem is an important resource for the survival of thousands of species of animals and plants. It has high ecological and economic value and has made great contributions to the protection and maintenance of marine and terrestrial ecological environment. However, due to climatic and human factors, the mangrove ecosystem has been destroyed and its ecological functions have been damaged. As an important indicator species, fishes have also been affected, with changes in their population and nutritional structure. This study summarized the mangrove fish in China and compiled a relatively complete list of mangrove fish. In addition, the biogeographic characteristics of Chinese mangrove fish were analyzed, filling the gap of national mangrove fish distribution data. Completion of this study contributed to a better understanding of the role of mangroves in maintaining the stability and diversity of fish communities, which was of great value for the management and conservation of regional and global biodiversity. Mangroves are among the most productive marine and coastal ecosystems and play an important role in maintaining the stability and diversity of fish communities. To explore the structure of mangrove fish communities in China, we compiled previous studies, monographs, and two databases on 54 mangrove areas published in the past 30 years. Mangrove fish communities in China comprised Osteichthys (597 species) and Chondrichthyes (14 species), representing 611 species in 344 genera, 117 families, and 28 orders. Perciformes were the predominant taxon, with 350 species in 52 families, accounting for 57% of the total species richness. Reef fish accounted for 29.62%. With regard to feeding groups, there were 328 carnivorous species (53.68%), 214 omnivorous species (35.02%), 41 herbivorous species (6.71%), and 28 detritivores species (4.58%). Classified by body size, 57.61% were small-sized, 24.22% medium-sized, and 18.17% were large-sized fishes. A total of 5.23% (32 species) of these mangrove fish are currently on IUCN red lists, i.e., 2 species are critically endangered, 4 are endangered, 12 are vulnerable, and 14 are near threatened. Cluster analyses shows that Chinese mangroves fish were divided into two categories, i.e., coastal mangrove and island mangrove type. This is closely related to the distribution of reef fish. Moreover, the number of fish species showed a strong positive correlation with mangrove area, but not with latitude. The main reasons may be the subtropical and tropical geographic locations, as well as the characteristics of the South China Sea and the Taiwan Warm Current. The size and integrity of mangrove area are crucial to the local ecosystems; thus, protecting and restoring mangroves is of great significance to large-scale ecosystem-stability and local biodiversity. [ABSTRACT FROM AUTHOR]

Stocking of silver carp [Hypophthalmichthys molitrix (Val.)] is a common tool used in eutrophic aquatic systems to control phytoplankton. As the mesh size of gill rakers undergoes change as growth proceeds, the particle selectivity and dietary importance of phytoplankton in younger fish may be different than those in older individuals. We conducted an enclosure experiment to assess how a gradient of fish size affected grazing pressure. The presence of fish strongly reduced zooplankton biomass and phosphorus (P) excretion, and P sequestered by fish could largely account for the lower total phosphorus (TP) concentrations observed in the presence of fish than in their absence. Moreover, the nutritional importance of phytoplankton in fish decreased with increasing fish size. Both the overall P excretion and grazing pressure decreased, whereas phytoplankton biomass and the yield of chlorophyll a per TP increased with increasing fish size. This suggested that phytoplankton might become more limited by P availability but less controlled by grazing with increasing fish size. Stocking with large silver carp would strongly reduce grazing pressure and increase the yield of phytoplankton per TP. [ABSTRACT FROM AUTHOR]

Riverine ecosystems contribute considerable fisheries production. However, in Ethiopia, there is a lack of comprehensive biological studies on such ecosystems. This study assessed the feeding habits of commercially important fishes of the Ayima and Gelegu Rivers. Fishes' guts were sampled seasonally from April 2017 to November 2018 using gill nets, cast nets and electrofishing. Four hundred and forty‐nine stomachs were analysed. Niche breadth and overlap indices were estimated using Levin and Schoener indices, respectively. The data indicated that Clarias gariepinus (Burchell, 1822), Bagrus docmak (Forsskål, 1775) and Hydrocynus forskahlii (Cuvier, 1819) mostly preyed on fish, whereas Heterotis niloticus (Cuvier, 1829) and Labeobarbus bynni (Forsskål, 1775) consumed detritus and macrophytes. H. niloticus, L. bynni and H. forskahlii were generalist feeders. There was a slight ontogenetic dietary shift observed in some predator fishes. In smaller sized L. bynni (6–20 cm, TL), insects and ostracods were important preys and their contribution differed significantly (p < 0.05). In H. forskahlii, the volumetric contribution of bivalves and detritus differed significantly amongst the different size classes. Generally, resource availability had little effect on the feeding behaviour of most fishes. This implies that fishes in floodplain rivers can forage any available prey without preference and accustom to a general feeding strategy to form biologically insignificant dietary overlap. [ABSTRACT FROM AUTHOR]

Background: The dung beetle Phelotrupes auratus is a holometabolous insect belonging to the order Coleoptera, and it is widely distributed in Japan. The P. auratus habitat depends on herbivores. P. auratus eats the dung of the herbivores and carries it underground for its young. In this process, herbivore droppings disappear from the ground, not only keeping the ground hygienic but also maintaining good soil conditions for plant growth. In this way, a rich ecosystem is maintained. In recent years, the population of P. auratus has decreased, and the main cause has been the decrease in grazing land. It seems that Japanese dung beetles are mainly dependent on herbivores for nutrient sources. However, the physiological relationship between herbivores and P. auratus has not been well investigated. Here, we investigated the nutritional metabolism system of P. auratus by performing whole gene expression analysis of individuals collected from two areas where the ecosystem is occupied by different herbivores. Results: We obtained 54,635 transcripts from P. auratus from Nara Park and Cape Toi and identified 2,592 differentially expressed genes in the fat bodies of the Nara Park and Cape Toi groups. We annotated P. auratus transcripts using Homo sapiens and Drosophila melanogaster genes as references; 50.5% of P. auratus transcripts were assigned to H. sapiens genes, and 54.0% of P. auratus transcripts were assigned to D. melanogaster genes. To perform gene set enrichment analysis, we chose H. sapiens genes for P. auratus transcript annotation. Principal component analysis and gene set enrichment analysis revealed that the nutritional metabolism of P. auratus from Cape Toi might differ from that of P. auratus from Nara Park. Conclusion: We analyzed the nutritional metabolism system of P. auratus from Cape Toi and Nara Park and found that the characteristics of the nutritional metabolism process might depend on the plants consumed by the herbivores. Our findings will contribute to elucidating the relationships among habitat plants, herbivores, and dung decomposers and may aid in the maintenance of sustainable land health cycles. [ABSTRACT FROM AUTHOR]

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Aquatic macrophytes are generally recognized to influence fish–prey interactions. We assessed how fish consume particular foods, and how their foraging efficiency, trophic niche breadth, and niche overlap respond to gradients of macrophyte density and diversity. We sampled fish and macrophytes in 30 stands distributed over a 13.7 km stretch of the littoral zone of a river in Brazil. By generating generalized linear models, we showed that increasing macrophyte density (from 366 to 7066 g DW m−3) favored herbivory and fish foraging efficiency. Beta regressions showed that fish reduced their trophic niche breadth along the gradient of macrophyte density, while niche overlap increased until a certain extent of plant density when species started to segregate the niche more strongly. However, niche breadth responses varied according to the trophic guild considered, with omnivorous and herbivorous fish generally showing opposite responses. Macrophyte diversity was important for the preferred food items of the fish, with stomach contents shifting from higher plants, algae, and detritus to insects with increasing macrophyte diversity. Therefore, in addition to the presumable effects of macrophyte density on resource availability and prey encounter rates, our findings highlight the importance of maintaining diverse macrophyte stands for the conservation of fish diversity. [ABSTRACT FROM AUTHOR]