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The spread of the Indo-Pacific lionfish Pterois miles into the Atlantic Ocean represents a well-known example of a successful invasion. Lionfish have successfully invaded the Atlantic, aided by biological traits such as high thermal tolerance, adaptability to various salinities, high fecundity, conspicuous defences and generalist feeding habits. The Mediterranean Sea is now experiencing an early-stage lionfish invasion, spreading westward from the eastern Mediterranean, likely through the Suez Canal. Using ecological niche modelling under various climate scenarios, we predict the potential spread of lionfish, identifying regions from low to high habitat suitability. Predictions indicate significant expansion, especially in the eastern and central Mediterranean, under greater warming scenarios. This expansion could lead to substantial declines in native species, decimation of commercially important fish stocks and trophic cascades, severely impacting local economies and marine biodiversity. Urgent understanding and management of lionfish impacts in the Mediterranean are essential, given their established presence in the western Atlantic and documented ecological consequences. [ABSTRACT FROM AUTHOR]

Sound is a valuable cue in the marine environment that can inform animals about habitat location and community composition. Indeed, sound is often used for orientation and navigation by larval reef fishes during settlement. However, despite sound's role in the early life of reef fishes, whether post-settlement reef fishes use ambient soundscapes to inform their movement decisions remains less clear. In an in-situ playback experiment in Curaçao, the Dutch Caribbean, settled individuals of an invasive predator, the Indo-Pacific lionfish (Pterois volitans), showed no preference to move towards the playbacks of two different habitat types during daylight hours. In particular, lionfish did not prefer to move towards the sounds of sandy or reef habitat playbacks when tested against a silent control. Moreover, when given a choice between simultaneous sandy and reef habitat playbacks, lionfish showed no preference for the soundscape of either habitat type. While the activity of lionfish was strongly correlated with their body size, with larger fish being more active, activity was not affected by habitat playback, nor did body size affect their preference for the soundscapes of either habitat type. While acoustic lures have been speculated to be a promising addition to existing lionfish trap designs, daytime playbacks of ambient soundscapes are unlikely to be successful in attracting lionfish post-settlement, ultimately affecting their efficacy. [ABSTRACT FROM AUTHOR]

The common lionfish, Pterois miles (Bennett, 1828), is one of the most recent Lessepsian migrants into Mediterranean Sea. In this study, a first attempt is made to explore some life history parameters of the species in the Messenian Gulf (SW Greece). Its growth, morphometry, and feeding behavior were studied in samples collected with a speargun during the summer and autumn of 2021 at depths from 0 m to 20 m. Lionfish were found to have established a thriving population, growing faster and reaching larger sizes than in their native range. Analysis of their diet showed that this species is a generalized feeder with a preference towards piscivory, targeting key species for local food webs, such as the damselfish (C. chromis), possibly provoking competition with other native predators. Overall, the dietary habits of the species, rapid growth rate, and lack of predation pressure make the lionfish an additional risk for the integrity of the Messenian marine ecosystem, an ecosystem which is already disturbed by intense human intervention. [ABSTRACT FROM AUTHOR]

Marine protected areas (MPAs) can protect and restore marine biodiversity and fisheries, but there are concerns that they may also benefit invasive species. The spatial and temporal colonization of invasive lionfish (Pterois miles) in the eastern Mediterranean was compared across zones with varying fishing restrictions (no fishing, recreational and commercial fishing, and commercial fishing only), and stations where targeted removal events were conducted by volunteer SCUBA divers. Lionfish density in no fishing areas was nearly double that of areas with commercial fishing only, and over four times greater than in areas where both commercial and recreational fishing were allowed. Lionfish density increased with depth, possibly due to easier human exploitation in shallow waters (0–10 m) that are accessible to recreational spearfishers. Targeted removals by volunteer divers decreased lionfish densities by over 60%, while areas without removals had a 200%–400% increase. Along with management actions, natural and ecological processes might drive lionfish densities within MPAs, and the speed with which lionfish colonized fishery‐restricted zones, emphasized the need for a more sophisticated MPA management strategy that considers invasive species impacts and dynamics in an ecosystem‐based approach. [ABSTRACT FROM AUTHOR]

Invasive species pose serious threats to ecosystems. To reduce ecological and economic consequences of invasions, efforts are made to control invaders and evaluating the effects of such efforts is paramount. Lionfishes (Pterois volitans and Pterois miles) are native to the Indo‐Pacific Ocean and pose a major threat to local ecosystems in the invaded Atlantic and Mediterranean. Culling via spearfishing is a widespread measure to limit lionfish population size in invaded ranges. However, like most hunted fishes, lionfish alter their behavior after repeated culling, potentially decreasing the effectiveness of future culls. Previous studies on lionfish in the Caribbean have shown that lionfish are less bold after repeated culling. However, the impact of culling on lionfish in their newest invasive range, the Mediterranean, remains enigmatic. To determine the behavioral changes in response to culling in this second area of invasion, we tested for effects of culling on the behavior of lionfish in Cyprus, a region heavily impacted by the lionfish invasion in the Mediterranean. We compared the response of lionfish to an approaching free diver holding a metal pole (imitating a spear fisher) between protected areas where spearfishing is restricted and areas where culls are frequently conducted. We also assessed whether activity, hiding pattern, and site fidelity differed between these culled and unculled sites. Overall, we found limited effects of culling on the traits measured, indicating surprising resistance to culling‐induced behavioral changes in Mediterranean lionfish. Future studies should monitor invasive lionfish population densities and the effects of culling in more detail to tailor management plans and reduce the negative effects of these fish in specific invaded ranges. [ABSTRACT FROM AUTHOR]

The Mediterranean basin has faced an increased influx of invasive species since the Suez Canal expansion in 2015. The invasive lionfish species, Pteroismiles, has rapidly established new populations in the Eastern Mediterranean Sea, impacting local fish biodiversity. Here, we have developed a new, fast (< 35 min) molecular approach to detect and quantify P. miles environmental DNA (eDNA) in combination with a portable device for field-based analysis. Using a species-specific real-time colorimetric loop-mediated isothermal amplification (qcLAMP) for the cytochrome oxidase subunit 1 (COI) gene, we demonstrate a high sensitivity with a limit of detection of 0.002 ng DNA per reaction, equivalent to only 50 copies of the COI gene. The assay is specific to the target in the presence of closely related and cooccurring species, and it is quantitative over five orders of magnitude. We validated the assay using aquarium water samples and further demonstrated its utility on natural eDNA samples collected from locations around the island of Crete where P. miles had been sighted. P. miles was indeed detected in three out of nine locations, two nature reserves and a closed bay. Lack of detection in the remaining locations suggests that populations are still at a low density. We also demonstrate the feasibility of P. miles eDNA qualitative detection directly from the filter used to collect eDNAcontaining particles, completely omitting DNA extraction. Overall, we present a new approach for fast and targeted eDNA quantification. The developed LAMP assay together, with the quantitative real-time colorimetric detection approach, open new possibilities for monitoring invasive P. miles in the field. [ABSTRACT FROM AUTHOR]

The rate of biological invasions is steadily increasing, with major ecological and economic impacts accounting for billions of dollars in damage as a result. One spectacular example is the western Atlantic invasion by lionfishes. In the Mediterranean Sea, invasions from the Red Sea via the Suez Canal (termed Lessepsian invasions) comprise more than 100 fish species, including a recent invasion by lionfish. In light of the devastating effects of lionfish in the Caribbean Sea, understanding the dynamics of Mediterranean lionfish invasion is crucial. The Lessepsian lionfish invasion started in 2012, and rapidly spread to the central Mediterranean. Here, we used thousands of RAD seq genomic markers to study the population dynamics of this invasion. While we did not find a reduction in genetic diversity between source (Red Sea) and invasive (Mediterranean) populations (i.e., bottleneck effects), we found evidence of population structure within the invasive range in the Mediterranean Sea. We found that loci that are potentially under selection may play an important role in invasion success (in particular, genes involved in osmoregulation and fin spine sizes). Genomic approaches proved powerful in examining the ecological and evolutionary patterns of successful invaders and may be used as tools to understand and potentially mitigate future invasions. [ABSTRACT FROM AUTHOR]

Invasive species often severely impact ecosystems and human activities in the areas that they invade. The lionfishes Pterois miles and P. volitans are regarded as the most successful invasive fishes in marine ecosystems. In the last 40 years, these Indo-Pacific predators have established in the tropical western Atlantic Ocean, with well-documented detrimental effects on the local fish communities. Around 10 years ago, a second invasion began in the Mediterranean Sea, which is being colonised by P. miles. Given the invasive potential of P. miles and the fact that the ecology and biodiversity of the temperate/sub-tropical Mediterranean Sea offer a different setting from the tropical western Atlantic, specific knowledge on this second invasion is needed. Here, we: (i) review the scientific knowledge available on the ecology of invasive lionfishes, (ii) discuss such knowledge in the context of invasion ecology and (iii) suggest future research avenues on the P. miles invasion in the Mediterranean Sea. In addition, we offer an update on the spread of P. miles in the Mediterranean Sea. While the history and development of the Mediterranean invasion are resolved and some mitigation plans have been implemented locally, the study of the interactions of P. miles with Mediterranean species and their impact on the local biodiversity is in its infancy. Closing this gap will lead to important fundamental insights in invasion ecology and will result in predictions on the impact of P. miles on the ecology and ecosystem services of the Mediterranean Sea. Such information will have practical implications for policy-makers aiming to devise sound and efficient mitigation plans. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore ontogenetic changes in functional morphological traits of the invasive lionfish (Pterois volitans) and to test if they were associated with the ontogenetic dietary shifts previously documented for this species. We calculated nine functional indices based on body morphology, six associated with fish locomotion and three with prey capture functionality. In juvenile fish, the morphology associated with feeding provides greater mechanical advantages during prey capture due to higher feeding speeds. In contrast, in adults' locomotion is more efficient and is related to enhanced sustained swimming as the invader grows, but the suction index (related to the ability to generate flow rate to the mouth during feeding) decreases as lionfish grow bigger. Our results suggest ontogenetic changes in functional morphological features related to feeding and locomotion in the invader P. volitans, but these modifications do not seem to be the main driver of their ontogenetic dietary change. [ABSTRACT FROM AUTHOR]

Although the primary function of the swim bladder is buoyancy, it is also involved in hearing, and it can be associated with sonic muscles for voluntary sound production. The use of the swim bladder and associated muscles in sound production could be an exaptation since this is not its first function. We however lack models showing that the same muscles can be used in both movement and sound production. In this study, we investigate the functions of the muscles associated with the swim bladder in different Pteroinae (lionfish) species. Our results indicate that Pterois volitans, P. radiata and Dendrochirus zebra are able to produce long low‐frequency hums when disturbed. The deliberate movements of the fin spines during sound production suggest that these sounds may serve as aposematic signals. In P. volitans and P. radiata, hums can be punctuated by intermittent louder pulses called knocks. Analysis of sonic features, morphology, electromyography and histology strongly suggest that these sounds are most likely produced by muscles closely associated with the swim bladder. These muscles originate from the neurocranium and insert on the posterior part of the swim bladder. Additionally, cineradiography supports the hypothesis that these same muscles are involved in altering the swim bladder's length and angle, thereby influencing the pitch of the fish body and participating in manoeuvring and locomotion movements. Fast contraction of the muscle should be related to sound production whereas sustained contractions allows modifications in swim bladder shape and body pitch. [ABSTRACT FROM AUTHOR]

The expansion of lionfish Pterois miles across the Mediterranean Sea since its introduction via the Suez Canal has been rapid, but the mechanisms by which the expansion occurred have not been fully tested. By using a series of Lagrangian particle tracking simulations and high-resolution hydrodynamic models, we tested the hypothesis that passive dispersal of larvae could explain the east to west expansion of lionfish. By sequentially modelling the annual dispersal of larvae, from the first observation in Lebanon in 2012 and then modelling dispersal of larval from the simulated settlement sites, we showed that passive dispersal driven by ocean currents largely explained the observed expansion of lionfish until 2020. The spread of lionfish was likely restricted by environmental conditions when the population reached the central Mediterranean and the particle tracking simulations diverged from observations. The results emphasize the potential contribution of computational models in understanding the dispersal of non-indigenous and range expanding species in response to changing environmental conditions, identifying high risk areas, and guiding targeted surveillance, early detection, and informing management strategies for such species. Given that many non-indigenous species in the Mediterranean are introduced through a consistent pathway (the Suez Canal), the incorporation of interdisciplinary approaches and high-resolution biophysical models can provide fundamental knowledge for management action prioritization. [ABSTRACT FROM AUTHOR]

Invasive alien species pose a great challenge in conservation ecology. Rapid establishment of common lionfish (Pterois miles) in the eastern Mediterranean Sea and its ongoing westward expansion raises many questions about how to sustainably combat this invasion in the long term.Drawing on experiences from the western Atlantic invasion, citizen scientists were engaged and demonstrated the efficiency of long‐term coordinated removals for the first time in the Mediterranean Sea.Findings reveal a sustained participation and interest throughout the coordinated removal events that encourage the organization of future events. Removal Action Teams were found effective at reducing lionfish numbers in small (less than half a hectare) areas of high conservation value, when removals were repeated systematically.Single‐day lionfish derbies, operated at greater spatial scales, succeeded in a 50% reduction in lionfish abundance while removing most large (>30 cm) individuals from an area after three consecutive events.Given the recreational character of such activities, coordinated removals are useful options for management and conservation when guided by competent authorities and supported by citizens, as they promote marine environmental awareness and help develop a sense of stewardship among members of the public. [ABSTRACT FROM AUTHOR]

In 2020, multiple lionfish (Pterois spp.) records along the equatorial Southwestern (SW) Atlantic revealed a new expansion of these potentially damaging invasive populations, which could impact over 3500 km of Brazilian coastline over the next few years, as well as unique ecosystems and marine protected areas in its path. To assess the taxonomic status, invasion route, and correlation with other centres of distribution, we investigated the genetic diversity patterns of lionfish caught in 2022 at the Amazonia, Northeastern Brazil, and Fernando de Noronha and Rocas Atoll ecoregions, using two molecular markers, the mitochondrial COI and the nuclear S7 RP1. The data indicate that all studied lionfish belong to what is generally accepted as P. volitans, and share the same genetic signature as lionfish present in the Caribbean Sea. The shared haplotypes and alleles indicate that the SW Atlantic invasion derives from an active movement of adult individuals from the Caribbean Sea into the Brazilian coast. The Amazon mesophotic reefs likely served as a stepping-stone to overcome the biogeographical barrier represented by the Amazon-Orinoco River plume. New alleles found for S7 RP1 suggest the onset of local genetic diversification, heightening the environmental risks as this bioinvasion heads towards other South Atlantic ecoregions. [ABSTRACT FROM AUTHOR]

The invasive alien species Pterois sp. has strongly invaded the Western Atlantic and the Caribbean Sea since the 1980s. Many studies have been set up to monitor this species. This study is the first to carry out a follow-up of these populations by capture-marking-recapture with photo-identification in a natural environment. The monitoring was carried out over a period of five months at two sites to the south of Martinique. The photo-identification technique showed a high efficiency of the method with important recapture rates (36.51% on Acropora and 43.59% on Trois Rivières). The study allowed an estimation of the population sizes and density on the sites (619 individuals per hectare on Acropora and 341 individuals per hectare on Trois Rivières). The recolonization of individuals according to their size class was also studied and showed greater movements of small individuals and a high site fidelity of larger ones. [ABSTRACT FROM AUTHOR]

Lionfish (Pterois volitans) have proliferated over the Caribbean Sea causing massive damage to coral reefs ecosystems. The development of products using lionfish is a control strategy that aims to decrease the negative impact of this species. In this research, the lionfish was processed to obtain surimi with a different set of binders (liquid egg white and starch) and high-power ultrasound. The surimi was used to elaborate two novel products: snacks and dipping sauce. A sensory panel was organized to determine the culinary applications with the highest appeal. The most liked fish snacks were obtained with ultrasound: (1) without binders and (2) with starch (3%). In case of dipping sauce, the most liked one was made by conventional method and egg white (1.5%). The use of ultrasound to obtain lionfish surimi in combination with binders demonstrated its potential to be used in the preparation of novel products with high sensory qualities. [ABSTRACT FROM AUTHOR]

The lionfish is an exotic invasive fish native to the Indo-Pacific, which is established in the western Atlantic Ocean and the Caribbean Sea. Lionfish can affect native fishes and invertebrates through direct predation or competition for food. The present review aims to analyze the most relevant characteristics of the biology and ecology of lionfish as an invasive alien species, with an emphasis on Cuba. We provide a current view of the well-known lionfish as a successful invasive fish, and we put in this context the information regarding lionfish in Cuban waters, enriching the background knowledge, and giving novel and relevant information. The compilation of numerous publications on the subject has allowed for a more complete analysis of essential aspects of this invader in the Cuban archipelago. The consulted literature records that the first report of lionfish in Cuba occurred in 2007; subsequently, sightings of lionfish were reported in numerous localities. In 2010, the lionfish was considered an invasive alien species, which currently is established in various habitats, at depths up to 188 m, throughout the Cuban archipelago (e.g., coral reefs, mangroves, seagrass beds, submerged artificial structures). In addition, it has reached very high densities (12.42 ind./100 m2), which exceed those reported in the Indo-Pacific as well as in many locations in the Western Atlantic. It has been confirmed that the lionfish in Cuba also presents numerous characteristics that guarantee its success as an invader, among them: less quantity and diversity of parasites than other Atlantic fishes found in similar environments, a high number of gametes in the gonads, reproductive activity during all year and wide diet. The most important fish families for the lionfish diet in Cuba have been Pomacentridae, Gobiidae, Scaridae, Holocentridae, Mullidae, Labridae and Acanthuridae; and the most important crustacean orders are Decapoda, Mysida, Stomatopoda and Isopoda. In Cuba, as in the entire invaded region, numerous investigations have been directed to evaluate the impact of this invader on ecosystems, and although there is enough information, their results differ. Additional studies are required to assess the impact of lionfish as a predator after several years of invasion on a larger geographic scale in Cuba and other areas of the region. This knowledge will allow the development of more effective control strategies. Periodic lionfish culling have been carried out in Cuban MPAs as a control strategy, and some positive results have been observed, such as the average size reduction; however, further efforts are still required. Due to the importance of the study of lionfish as an invader, this review is a necessity as it provides, for the first time, a comprehensive analysis of lionfish information and results from Cuba, which is adequately contrasted with previous studies of other areas, particularly, from the Greater Caribbean. [ABSTRACT FROM AUTHOR]

The diet of the lionfish (Pterois miles), an invasive species in the Aegean Sea, was examined by collecting stomach content data from fish collected in three study sites in the Aegean Sea (southern Crete, Kastellorizo, and Nysiros islands). Prey composition in terms of numerical abundance and frequency of occurrence was used to compare lionfish's diet between these sites. Lionfish largely preyed upon teleosts (4% to 83% numerical abundance and 16% to 58% frequency of occurrence, depending on the site) and decapods (12% to 95% numerical abundance and 11% to 81% frequency of occurrence). The most important teleost families in lionfish's diet were Gobiidae, Labridae, and Scorpaenidae, while decapods and especially the family Scyllaridae and the genus Plesionika were the dominant decapod prey items. The lionfish was found to be an especially successful generalist across the study sites, an opportunistic, predatory species overall, and at the same time, at a local level, it seems to be an equally successful specialist that could increase the predation mortality of already stressed prey populations and can be a serious threat to endemic, critically endangered, and/or commercially important species. [ABSTRACT FROM AUTHOR]

Invasive lionfish (Pterois volitans, Pterois miles), introduced to Florida in the 1980s, colonized coral reef ecosystems in the western Atlantic and have been documented beyond recreational diving depths. In addition to threatening coral reef ecosystems, invasive lionfish have been linked to economic damage in the form of reduced native fish yields for local fishers and high management costs incurred in the physical removal of lionfish.While few examples exist of successful management of marine invasive species, studies show that lionfish removal can mitigate their harmful impacts. One promising market‐based approach that offers benefits to both human livelihoods and marine ecosystems is increasing the demand for the consumption of lionfish. This study focuses on Florida's consumptive lionfish market and fills a gap in understanding of the lionfish supply chain for Florida's restaurant industry.Twenty culinary professionals in Florida were interviewed to determine their perceptions of barriers and opportunities for increasing their use of lionfish. The most commonly identified barriers were price and consistency of supply, while the most prominent opportunities were improved awareness and culinary potential. Conservation managers, culinary professionals and policymakers should leverage these findings to facilitate opportunities, address barriers and promote public education about invasive lionfish and their impacts. [ABSTRACT FROM AUTHOR]

Invasive lionfish (Pterois miles and P. volitans) populations are now pervasive across the Caribbean and Western Atlantic. These generalist mesopredators have the potential to negatively impact reef fish populations throughout their invaded range. Targeted removal by culling has been shown as an effective way to manage shallow-water lionfish densities, however, lionfish are found across a broad depth range, with reproductive populations found at mesophotic depth. This study aimed to determine the efficacy of short-term culling of mesophotic lionfish populations and its impact on resident reef fish populations. Surveys of lionfish and reef fish populations were conducted monthly at three mesophotic reef sites in Bermuda from July to December 2017, with subsequent surveys six and 12 months later. During each survey, all lionfish were removed, measured, and sexed. Lionfish density was found to decrease significantly over the recurrent culling period, with the rate of recolonization declining as density declined, resulting in continued reductions with each subsequent culling. The percent of females also declined during recurrent culling, suggesting that culling may further reduce population stability through impacts to reproductive potential. Reef fish community composition changed throughout the study, with shifts in dominant species and trophic groups despite stable species richness and diversity. However, fluctuations in lionfish density as well as reef fish density and biomass reflected patterns of seasonality indicating that impacts of the physical environment may mask the influence of lionfish culling. Overall, these data suggest that culling of invasive lionfish on mesophotic reefs should target high density sites and seasonal aggregations in order to effectively contribute to management strategies. [ABSTRACT FROM AUTHOR]

Populations of lionfish (Pterois volitans Linnaeus, 1758; Pterois miles Bennett, 1828) have expanded in the western Atlantic Ocean and the Mediterranean Sea since their introduction and have become a biological invasive species. This invasion has impacted these regions' marine biodiversity, and their impact is expected to increase due to climate change. Our work evaluated the current and future potential risk of lionfish populations during climate change scenarios based on the Maximum Entropy (MaxEnt) model. MaxEnt was used to predict lionfish populations' suitability for current conditions and under two Representative Concentration Pathway scenarios (RCP 4.5 and 8.5) for 2040–2050 and 2090–2100. Lionfish had an estimated range of physiological tolerances from 10–15 °C to 30 °C. According to our analyses, lionfish can live off the coasts of western Africa, the Americas, and the Mediterranean Sea. Under mild warming scenarios, suitable conditions for lionfish could expand to higher latitudes due to their high thermal range and salinity tolerance. Our models predicted that lionfish could reach the coasts of France, the United Kingdom, Uruguay, South Africa, and New Zealand, among other regions, under warming scenarios. However, under the warmest scenario (RCP 8.5), tropical latitudes may become less suitable for lionfish, particularly in the Indo-Pacific region. Our results may be useful for resource managers to foresee where to increase efforts in lionfish fisheries and consumption. [ABSTRACT FROM AUTHOR]

"If you can't beat 'em, eat 'em": the development of commercial markets is an emerging strategy to control invasive species. This strategy may have fewer unintended ecological impacts than genetic modification and biological control; however, its unintended social impacts are poorly understood. We discuss the social dilemmas and opportunities created by commercializing invasive species, based on the experiences of fishing cooperatives' harvest of invasive lionfish (Pterois sp.) in the Mexican Caribbean. In Cozumel, Mexico, a pilot commercial fishery began in 2012, and by 2015 had seemingly succeeded at reducing local lionfish abundance. However, three social dilemmas have accompanied this process. First, though designed to support sustainability, this market disproportionately benefits fishers that use fishing gear considered "unsustainable". Second, this strategy reinforces the narrative of fishers trapped in a "tragedy of the commons," while simultaneously depending on the fishers' participation. Finally, the programme's very success has led to its own demise, disproportionately affecting the programme's most invested participants. These and similar dilemmas may be inevitable when systems in place for sustainable resource harvest are repurposed for resource collapse. However, fishing cooperatives have managed to navigate these dilemmas in partnership with governmental and non-governmental organization (NGO) advocates to position themselves as conservation leaders. [ABSTRACT FROM AUTHOR]

Objective: Cutaneous ulcerative skin lesions in a complex of invasive Gulf of Mexico lionfish (Red Lionfish Pterois volitans, Devil Firefish P. miles, and the hybrid Red Lionfish × Devil Firefish) became epizootic beginning in mid‐August 2017. Herein, we provide the first pathological descriptions of these lesions and summarize our analyses to elucidate the etiology of the disease. Methods: We examined ulcerated and normal fish through gross pathology and histopathology, bacterial sampling, and unbiased metagenomic next‐generation sequencing. We tracked prevalence of the disease, and we used biological health indicators (condition factor, splenosomatic and hepatosomatic index) to evaluate impacts to health, while considering sex and age as potential risk factors. Result: Typical ulcerative lesions were deep, exposing skeletal muscle, and were bordered by pale or reddened areas often with some degree of scale loss. Only incidental parasites were found in our examinations. Most fish (86%; n = 50) exhibited wound healing grossly and histologically, confirmed by the presence of granulation tissues. A primary bacterial pathogen was not evident through bacterial culture or histopathology. Metagenomic next‐generation sequencing did not reveal a viral pathogen (DNA or RNA) but did provide information about the microbiome of some ulcerated specimens. Compared with clinically healthy fish, ulcerated fish had a significantly lower condition factor and a higher splenosomatic index. Disease prevalence at monitored sites through July 2021 indicated that ulcerated fish were still present but at substantially lower prevalence than observed in 2017. Conclusion: Although some common findings in a number of specimens suggest a potential role for opportunistic bacteria, collectively our suite of diagnostics and analyses did not reveal an intralesional infectious agent, and we must consider the possibility that there was no communicable pathogen. Impact StatementAn outbreak of ulcers affected lionfish in the Gulf of Mexico. The disease occurred coincident to declines in invasive lionfish populations but could be contagious to native fish. Sick fish were examined to determine the cause. Findings were inconclusive but bacteria and environmental factors should be further investigated. [ABSTRACT FROM AUTHOR]

Indo‐Pacific lionfishes generally exhibit cryptic behaviours and so can be missed when conducting non‐targeted surveys. Here, the authors report the results from targeted surveys of lionfish at Moorea, French Polynesia. Lionfish from three species (Pterois antennata, Pterois radiata, Dendrochirus biocellatus) were observed at a mean density of 267 individuals ha−1. This is substantially higher than previous estimates from the same area (Moorea) and represents the highest reported density of lionfishes from their Pacific range. Overall, this study highlights the importance of targeted survey techniques for detecting cryptic species on coral reefs. [ABSTRACT FROM AUTHOR]

A taxonomic revision of the genus Parapterois (Scorpaenidae: Pteroinae) resulted in recognition of three valid species, Pa. heterura (Bleeker 1856) (type locality: Indonesia), Pa. macrura (Alcock 1896) (India) and Pa. nigripinnis (Gilchrist 1904) (South Africa). Previously regarded (as Pterois nigripinnis) as a junior synonym of Pterois heterurus Bleeker 1856, the last-mentioned is readily distinguishable from its congeners by having interrupted or wavy white lines and/or spots present below the eye (vs. solid white lines in congeners) and the pectoral-fin axilla with many white spots (vs. spots absent). Although Pa. macrura is most similar to Pa. heterura, the two species can be distinguished from each other by several morphometric characters, including the relative position of the orbit (with respect to the top of the nasal protuberance and the first dorsal-fin base), and the number of spinules on the cheek scales. Parapterois heterura is widely distributed in the eastern Indian and western Pacific oceans, whereas Pa. macrura and Pa. nigripinnis are restricted to the Arabian and Laccadive seas, and the southwestern Indian Ocean (east coasts of Mozambique and South Africa), respectively. Pterois jordani Regan 1905, Ebosia starksi Franz 1910, Pterois tanabensis Tanaka 1918 and Ebosia pavo Schmidt 1931, all described from Japan, are regarded as junior synonyms of Pt. heterurus. Pterois natalensis von Bonde 1923 (type locality: South Africa) is synonymized under Pt. nigripinnis. Lectotypes are designated for Pt. macrura and Pt. nigripinnis, and a key to species of Parapterois is provided. [ABSTRACT FROM AUTHOR]

Cuba's shelf has been invaded by lionfish (Pterois volitans/Pterois miles), which have become established over the archipelago, including areas of natural importance. The present study aims to evaluate morphometric features of lionfish and to explore the relationship between lionfish size and diet composition in different habitats in the Punta Frances National Park, Cuba. In total 620 lionfish were captured at 29 sites between 2013 and 2016. Lionfish stomachs were removed and their contents were analyzed using frequency and numerical methods. The length-weight allomentric relationship was obtained, and a decrease in lionfish sizes was shown over time, likely due to the extractions carried out. The diet was composed by fishes, crustaceans, mollusks and phytobenthos, with a predominance of fishes. Lionfish caught in seagrass beds tended to be smaller in size and consumed fewer fishes and more crustaceans than those captured in coral reefs. A positive correlation was observed between lionfish body size and gape size; however, no significant correlation was detected between lionfish body size and prey size. Larger lionfish tended to consume more fishes, while crustaceans were more significant in the diet of juvenile lionfish. This is the first study that examines the feeding habits of lionfish in the Punta Frances MPA, and provides valuable information on lionfish inhabiting this MPA across four years of sampling. Furthermore, this research may serve as a baseline for subsequent evaluations of lionfish impact and management actions in the area. [ABSTRACT FROM AUTHOR]

Suboptimal nutrition may contribute to lionfish (Pterois volitans and Pterois miles) health issues in managed care environments. This study's objective was to establish and compare whole blood fatty acid profiles in wild and aquarium lionfish. Whole blood samples were dried onto specialized high-quality paper cards from wild, invasive lionfish harvested off the North Carolina coast (n = 16) and lionfish managed by the North Carolina Aquariums (n = 12). Blood fatty acid profiles were analyzed from dried blood spots. Aquarium lionfish had significantly (p < 0.05) higher linoleic (18:2ω6) and eicosapentaenoic (20:5ω3) acid levels than wild lionfish. Similarly, aquarium lionfish had significantly (p < 0.05) lower saturated fatty acids and arachidonic (20:4ω6) to eicosapentaenoic acid (20:5ω3) ratios than wild lionfish. Total omega-3 and omega-6 fatty acids, as well as the ratio of these two fatty acid groups, were similar between wild and aquarium lionfish. Gut content analysis of wild lionfish diets included reef-dependent and schooling fish while aquarium lionfish diets were pelagic fish, crustaceans, mollusks, and commercial gel diets with nutrient supplements. This study reports whole blood fatty acid profiles in lionfish, providing comparative macronutrient data that may be useful for improving their nutrition and welfare in aquariums. [ABSTRACT FROM AUTHOR]

The pursuit of prey is vital to the biology of a predator and many aspects of predatory behaviour are well-studied. However, it is unclear how a pursuit can be effective when the prey is faster than a non-cryptic predator. Using kinematic measurements, we considered the strategy of red lionfish (Pterois volitans) as they pursued a faster prey fish (Chromis viridis) under laboratory conditions. Despite swimming about half as fast as C. viridis, lionfish succeeded in capturing prey in 61% of our experiments. This successful pursuit behaviour was defined by three critical characteristics. First, lionfish targeted C. viridis with pure pursuit by adjusting their heading towards the prey's position and not the anticipated point of interception. Second, lionfish pursued prey with uninterrupted motion. By contrast, C. viridis moved intermittently with variation in speed that included slow swimming. Such periods allowed lionfish to close the distance to a prey and initiate a suction-feeding strike at a relatively close distance (less than 9 cm). Finally, lionfish exhibited a high rate of strike success, capturing prey in 74% of all strikes. These characteristics comprise a behaviour that we call the 'persistent-predation strategy', which may be exhibited by a diversity of predators with relatively slow locomotion. [ABSTRACT FROM AUTHOR]

Biodiversity redistribution is occurring at an unprecedented pace, with one prominent example being the invasion of the lionfish (Pterois miles) in the Mediterranean Sea, altering the fish community composition by creating novel interspecific interactions and potentially threatening local biodiversity. Our study attempts to identify patterns in the lionfish distribution and behaviour in the coastal zone of the eastern Ionian Sea (central Mediterranean). Over a 14-month period, visual censuses were conducted along coastal strip transects at six stations, situated in three areas (Mani, Katakolo, Astakos) across a latitudinal gradient. Lionfish density was highest in Mani, the southernmost area. Higher densities were found at two stations experiencing direct anthropogenic pressures: one with structural modifications by port infrastructure, and the other in the vicinity of a fish farm, indicating a potential role of human interventions in facilitating the establishment of invasive populations. Lionfish group size was influenced by overall density, exhibiting variation between the two natural stations. Lionfish activity levels by microhabitat were site-specific, with more inactive individuals in crevices. Temporal activity patterns were similar in the natural stations, with increased activity during spring and summer months; however, temporal activity patterns were not identical in the two anthropogenic sites, suggesting that the specific nature of anthropogenic intervention might possibly influence lionfish activity. Finally, lionfish densities were not significantly different between early morning and late afternoon times of day, in agreement with the crepuscular behaviour already documented for this species. • We carried out visual census in strip transects for lionfish (Pterois miles). • Density was the highest in the southernmost/the lowest in the northernmost area. • Higher densities at stations under anthropogenic pressures (port, fish farm). • Activity by microhabitat was site-specific. • Densities were not significantly different between sunrise and sunset. [ABSTRACT FROM AUTHOR]

The study was carried out in the Mediterranean region of Turkey between 2018 and 2021. It was aimed to reveal lionfish awareness studies and lionfish venoming cases in Turkey in this study. The awareness studies were determined by institutional studies. Personal interviews, first aid agency notifications and literature were investigated to find lionfish venoming cases. Four awareness studies and seven lionfish venoming cases were detected. Pain, swelling, and redness were often the first symptoms in the venoming cases. The first application was immersion in hot water in three of the seven cases. No deaths were recorded in the cases. In Turkey, the awareness studies should continue with the derbies or tournaments and government-supported removal efforts must be made to reduce the population and stocks of invasive lionfish. [ABSTRACT FROM AUTHOR]

Underwater visual census (UVC) is a commonly used approach for assessing fish density and biomass. Iskenderun Bay, comprising the Samandag coast in Turkey, is the most important introduction pathway of alien species in the northeastern Mediterranean. In this study, the density, abundance, distribution and interaction of invasive lionfish or devil firefish Pterois miles were assessed using the UVC method on the Samandağ coast. The total transect area monitored on the Samandağ coast was 4.500 m². Species richness, Shannon's diversity index and rate of biomass were 25, 1.81 and 73.5 m², respectively. Reduced diversity was observed with increasing depths. The sandy seafloor was a limiting factor for lionfish distribution. There was a significant positive correlation between lionfish total density and both the Shannon diversity index (r = 0.99, P<0.001) and Shannon evenness index (r = 0.99, P<0.05). A high number of significant positive correlations (P<0.05) were detected between the occurrence of lionfish and the occurrence of both the native species and other alien species. The first stock assessment study of lionfish by the UVC method in Turkish marine waters revealed that native species are under very high pressure from lionfish species, especially Chromis, Sparids and Wrasses, indicating negative effects of lionfish on regional native biodiversity. [ABSTRACT FROM AUTHOR]

The lionfish Pterois miles invaded the Mediterranean Sea in 2012 and spread fast to the entire eastern basin. This study provides evidence of successful spawning and the first detailed analysis of P. miles ovarian dynamics in the Mediterranean Sea. The ovarian reproductive phases of mature females collected from Cyprus (eastern Mediterranean) between September 2017 and August 2018 were analysed, both macroscopically and histologically. The results suggested a prolonged oocyte recruitment and development season, and a spawning season that primarily occurred during summertime, even though spawning-capable females were caught also in autumn. A year-round spawning activity may have been inhibited due to seasonal variations in water temperature. Multiple oocyte developmental stages co-occurred in females at different reproductive phases, indicating that more than one oocyte batches were released per spawning season. The analysis of the spawning batch formation enabled the batch fecundity estimation at 3225–63149 oocytes. The oocyte development pattern described in this study shared characteristics with the indeterminate fecundity type, where new oocytes are recruited to the secondary growth phase in parallel with spawning activity. Climate change is likely to extend the spawning season of lionfish in the Mediterranean Sea and further favour its invasion. The information provided in this study is vital for the design of strategic and effective management plans to restrain the expansion of this highly invasive fish. [ABSTRACT FROM AUTHOR]

Inventory of the fish inhabiting the Ciénaga de Zapata National Park, in the south of Matanzas province, were carried out on March and May 2018. This research presents the first check list of fish on this protected area published in peer-reviewed literature. The species identification was mainly in situ using random swimming but also reviewing 3968 minutes of baited remote underwater videos (BRUVs) and high resolution photographs. The inventory includes 169 species of 53 families. This adds 67 species to the list (no peerreviewed) of the Protected Area of Management Resources Península de Zapata ichthyofauna. High frequency of the invasive exotic species lionfish (Pterois volitans) (Linnaeus, 1758) is remarkable. In Ciénaga de Zapata National Park occurs 16 % of the Cuban ichthyofauna, 17 % of the strictly marine fish, 11 % of the Chondrichthyes and 18 % of the Actinopterygii. Diversity of taxa is high in Ciénaga de Zapata National Park, being the most diverse families generally the same among regions, although they rank different. Two potential spawning aggregation sites for fish, one of tiger grouper Mycteroperca tigris and one of black grouper (M. bonaci), were detected. [ABSTRACT FROM AUTHOR]

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Designing effective local management for invasive species poses a major challenge for conservation, yet factors affecting intervention success and efficiency are rarely evaluated and incorporated into practice. We coordinated regional efforts by divers to cull invasive lionfish (Pterois spp.) on 33 U.S. Atlantic, Gulf of Mexico, and Caribbean protected coral reefs from 2013 to 2019 and estimated removal efficiency and efficacy as a function of environmental and habitat conditions, invasion status, and personnel expertise. Highly experienced individuals culling during crepuscular periods (<2 hr from sunrise/sunset) are three times more efficient (in terms of minutes) than novice divers during midday, suggesting: (a) retention of experienced individuals is key for efficient programs, and (b) planning culls with personnel and time of day in mind increases the number of sites covered with the same effort. Lionfish behavior and habitat characteristics had little effect on removal efficiency and efficacy, but divers had higher capture success at reefs with higher lionfish densities. We suggest reefs with persistently <20 fish ha−1 as low priority, given that impacts to native fauna are unlikely and culling effectiveness declines to <50% below this level. Incorporating efficiency factors in spatial management planning along with density estimates derived from remotely sensed data can ensure limited resources for control are extended across a greater range of invaded habitats. [ABSTRACT FROM AUTHOR]

Invasive lionfish are considered to be one of the worst marine invaders primarily due to their threat as predators to native species. The distribution of lionfish across their invasive range has been fairly well characterized, but their presence within estuaries is largely unknown. While removal of invasive lionfish is the primary mode of managing the invasion, early detection in new locations could be valuable for documenting range expansion. Environmental DNA (eDNA) has become a useful tool to identify the presence of invasive species prior to establishment and may be especially valuable for systems that are challenging to survey. In this study, an environmental DNA assay was developed and successfully identified the presence of lionfish DNA in four riverine estuaries in the northern Gulf of Mexico. Detections were significantly higher in July but did not vary by location. Occupancy modeling shows that the assay is not exceptionally sensitive and may be underreporting the presence of lionfish, possibly due to the effect of salinity. The presence of invasive lionfish within estuaries could put native fish and invertebrates at risk, especially species that use these systems as nurseries. Ongoing monitoring using molecular methods may be useful in the management of invasive lionfish by providing early detection of fish moving into systems that neighbor known invaded regions. [ABSTRACT FROM AUTHOR]

Invasive aquatic species may disrupt ecosystems and cause socioeconomic damage. Biosecurity protocols were developed to prevent transport and unintended introductions of invasive species, but less attention has been paid to management once they become established. The use of classical fisheries stock assessment to determine levels at which selectively targeted fisheries elicit recruitment overfishing is discussed. Case studies of several species of invasive aquatic organisms, including lionfish Pterois spp. two species of mytilids and three species of crayfish, including Faxonius rusticus (Girard, 1852), are discussed as examples. Fecundity as measured by egg production rate (EPR) is a key factor determining how the various species react to fishing pressure. Ecosystem modelling of predatorprey relations between indigenous and invasive aquatic species suggests that restricting fishing effort on indigenous predators of invasive prey may be as effective in managing invasive species in lieu of directly increasing fishing effort on the targeted species itself. Invasive mytilids Dreissena polymorpha (Pallas, 1771) and Mytella strigata (Hanley, 1843) may not be effectively controlled by intensive fishing effort due to high EPR values. However, crayfish that brood offspring and exhibit much lower EPR values may be ideal candidates for stock assessment and setting fishing effort targets to promote recruitment overfishing. Recommendations for managing invasive aquatic species include: collecting data on population dynamics of the invasive species; assessing predator populations; developing fisheries that target the invasive species; and collecting socioeconomic data to understand the human dimensions of the impacts of the invasive species and inform subsequent policy development. [ABSTRACT FROM AUTHOR]

A lack of biosecurity in the Suez Canal has combined with global warming and other human pressures to cause abrupt changes in the Mediterranean Sea. Throughout this region an influx of species is influencing the outcome of efforts to protect and restore nature.Despite calls for targeted removals of invasive species from protected areas, there is limited information about the effectiveness of this course of action from both an ecological and a socio‐economic perspective. In this study, coordinated removals of lionfish (Pterois miles) by volunteers/scuba divers at three marine protected sites in Cyprus were conducted.The removal efficiency was monitored using visual‐census surveys and citizen science data. Removals significantly decreased lionfish numbers but long‐term suppression of lionfish would require monitoring and repetition of removals when necessary, since population recovery was sometimes rapid.Citizen science yielded the data needed to understand lionfish population changes and guide the timing of removal events, but was characterized by large variation and potential outliers, highlighting the need for large sample sizes.Questionnaire surveys were used to assess the social impact of participation in lionfish removals; these showed that involvement had a strong positive impact on knowledge about lionfish and motivation to support marine conservation activities – the divers were even willing to pay extra to remove lionfish.Management reforms would be needed to capitalize on this societal motivation, and enable effective lionfish removals by scuba divers, coordinated by competent authorities. The EU aims to protect at least 30% of the marine waters by 2030. Removal events could help shield selected conservation sites from the adverse effects of lionfish and at the same time help establish links with local communities, strengthening the sustainable use of marine systems both at corporate and at societal levels. [ABSTRACT FROM AUTHOR]

The impacts of invasive lionfish (Pterois volitans/miles) on native coral reef populations in the Western Atlantic Ocean and Caribbean Sea can be enormous. However, how much lionfish differ from native predators and whether their effects outweigh the abundant mesopredators that occupy many reefs invite continued examination. Here, we present empirical evidence from Caribbean Panama and beyond suggesting that lionfish are less abundant than native mesopredators. Furthermore, we show that their direct impacts on survivorship and size distributions of one native prey species are similar to those of a native mesopredator. These results support calls for lionfish management that considers evolving local ecological and social dynamics, including prey community composition, the roles of native mesopredators, and regional goals for conservation and fisheries. Recognition of regional context creates the potential for synergies between conservation actions aimed both at the invasion and other consequential problems such as overexploitation and climate change. [ABSTRACT FROM AUTHOR]

Invasive lionfish (Pterois volitans/miles) pose a serious threat to marine ecosystems throughout the western Atlantic Ocean and Caribbean Sea. The development of a fishery for lionfish has been proposed as a strategy for controlling populations; however, there is concern about consumption of this species by humans due to its high trophic position and potential for bioaccumulation of mercury. We analyzed total mercury (THg) in tissues of lionfish from two locations on the east coast of Florida. THg in lionfish increased with size and differed by location and sex. THg was highest in muscle tissue and was strongly positively correlated among tissues. THg in lionfish was lower than other commonly consumed marine fishes, and falls into Florida's least restrictive advisory level. Consumption of lionfish poses a low risk and concerns over mercury bioaccumulation should not present a significant barrier to lionfish harvest. [ABSTRACT FROM AUTHOR]

Predation from the invasive Indo‐Pacific lionfish is likely to amplify declines in marine fishes observed in multiple ocean basins. As the invasion intensifies and expands, there is an urgent need to identify species that are most at risk for extirpation—and possible extinction—from this added threat. To address this gap and inform conservation plans, we develop and apply a quantitative framework for classifying the relative vulnerability of fishes based on morphological and behavioural traits known to influence susceptibility to lionfish predation (e.g. body shape, water column position and aggregation behaviour), habitat overlap with lionfish, and degree of geographic range restriction. Applying the framework to fishes across the invaded Caribbean Sea and ahead of the invasion front in the southwestern Atlantic revealed the identity of at least 77 fishes with relatively small ranges that are likely to be most affected by lionfish predation. Trait‐based vulnerability scores significantly predict the probability of fishes appearing within the diets of lionfish across the invaded region. Spatial richness analyses reveal hotspots of vulnerable species in the Bahamas, Belize and Curaçao. Crucially, our framework identifies 29 vulnerable fishes endemic to Brazil, which has not yet been colonized by lionfish. Of these, we suggest reefs around offshore island groups occupied by a dozen highly vulnerable and range‐restricted species as priorities for intervention should lionfish spread to the region. Observations of the rate of lionfish spread across the invaded range suggest that an average of 5 years (with a median of nearly 2 years) elapses from first sighting to maximum observed densities. This lag may allow managers to mobilize plans to suppress lionfish ahead of an invasion front in priority locations. Our framework also provides a method for assessing the relative vulnerability of cryptobenthic and/or deep‐reef fishes, for which population‐monitoring data are limited. [ABSTRACT FROM AUTHOR]

Implementing new and effective control strategies to reduce populations of invasive species is needed to offset their negative impacts worldwide. The spread of Indo-Pacific lionfish (Pterois sp.) through much of the western Atlantic has been one of the most publicized marine invasions globally, and is considered a major biodiversity threat whose longer-term impacts are still uncertain. Marine managers have explored several strategies to control lionfish, such as fishing tournaments (derbies) and commercial fisheries. Commercial fisheries for invasive species are controversial because they could create perverse incentives to maintain these populations, and they have never been demonstrated to successfully control target populations. We analyzed the development and impacts of an opportunistic fishing operation aimed at commercializing invasive lionfish in the Mexican Caribbean. We examined official lionfish landings and compared them to catches from lionfish derbies and lionfish densities from locations in the state of Quintana Roo, Mexico. We found that commercial fishers, particularly from one fishing cooperative on Cozumel Island, were effective at catching lionfish, with landings peaking at 20,000 individuals in 2014. This number is comparable to the number of lionfish caught in derbies across the entire Caribbean in the same year. Ecological survey data suggest a ~ 60% reduction in lionfish density on Cozumel reefs over two years (2013–2015), matching the peak landings in the lionfish fishing operation. However, the fishery's apparent success as a control tool during the time window analyzed seemed to trigger its own demise: a decline in landings was followed by evaporating market interest and loss of economic viability. If fisheries are to be established and used as management strategies to control future invasions, managers must develop strategic collaboration plans with commercial fishing partners. [ABSTRACT FROM AUTHOR]

Biotic resistance is the ability of an ecological community to prevent or limit the establishment or success of non-indigenous species. Native species can confer resistance by outcompeting or directly consuming non-native invaders. The fear of being eaten could also limit invader success, but non-consumptive effects of native predators have rarely been documented as a source of biotic resistance. Here, we test whether native groupers on Caribbean coral reefs can promote biotic resistance to invasive Indo-Pacific lionfish through competition, consumption, and/or through non-consumptive effects. Stomach content analysis of more than 200 groupers, comprising five species, revealed no instances of predation on lionfish. To test for competitive and non-consumptive effects of groupers, we released tagged juvenile lionfish onto reef patches that varied in grouper densities and monitored lionfish behaviours over five weeks. At dawn, during peak grouper and lionfish hunting times, juvenile lionfish hid more on reefs with more grouper predators. Juvenile lionfish were also less active during the day on reefs with high grouper densities. Hiding and inactivity are incompatible with foraging and thus should result in lionfish eating fewer prey and having reduced somatic growth rates. Although there was no substantial effect of interspecific competition on lionfish behaviours, we found that lionfish swam greater distances with increasing densities of intraspecific competitors at dawn. We did not detect a cascading effect of grouper predators on smaller fishes, perhaps because the seasonal peak in prey fish recruitment masked the effects of lower lionfish predation. Fear of native predators by lionfish has the potential to reduce invader foraging success, although it might not fully mitigate the negative effects on native prey communities. Efforts to rebuild grouper populations throughout the Caribbean may still aid in controlling the lionfish invasion despite weak evidence of interspecific competition and lack of direct predation on lionfish, but further research is needed. At broader scales, our findings highlight that the global depletion of large predators can have implications beyond demographic effects on prey. [ABSTRACT FROM AUTHOR]

Chocó-Darien is an important biogeographic realm, as it is a terrestrial biodiversity hotspot and the southern limit of the Caribbean reefs. However, to date there are no compiled data on the reef fish assemblage of this region. We provide an updated checklist of marine fishes from the Chocó-Darien reef system (Colombia), with comments on their geographic distribution and conservation status. Peer-reviewed studies, unpublished data and in situ visual censuses were surveyed to compose this checklist. A total of 212 reef fish species across 57 families were compiled, eight of which had no previously published records, one of which (Trachinotus falcatus) is recorded for the first time. The most speciose families were Labridae (n = 21), Gobiidae (n = 18) and Serranidae (n = 17). Fourteen threatened species were recorded, including one critically endangered (Epinephelus striatus) and two endangered (Balistes vetula and Scarus coelestinus). This study contributes to fill the knowledge gaps on the reef fish diversity of the Caribbean southern limit and raises concern on the spread of the lionfish invasion into the Chocó-Darién reef system. [ABSTRACT FROM AUTHOR]

Volunteers are extensively involved in monitoring and controlling invasive species. Most research has examined volunteer activity in groups organized "top-down", but we examined a local community-based group removing lionfish in the British Virgin Islands (BVI) with a specific focus on the use of social media by the group. Indo-Pacific lionfish (Pterois miles, P. lunulate and P. russelii) are invasive in the Western Atlantic Ocean and can impact the composition and function of coral reef communities. In response, resource managers and scientists have organized programs using divers and snorkelers to remove lionfish. In the volunteer-led BVI program, participants searched for and culled lionfish in their spare time and used a public Facebook group to record their activity. We compiled all lionfish-related posts from 2012 to 2014 (n = 654). Lionfish were reported at 147 sites, and 1451 lionfish were culled from 117 sites, but activity was concentrated at 35 established dive/snorkeling sites. We also performed SCUBA surveys (n = 27 sites). Survey results were consistent with Facebook reports in suggesting that culling made lionfish wary but did not consistently reduce lionfish abundance or size-distributions. Most removals were conducted by a core group of locals whereas a much larger group of locals and visitors, some of whom apparently participated after seeing the Facebook page, contributed mainly by reporting the location of sightings. Those removing lionfish frequently followed-up on posted sightings, suggesting that social networking facilitated information sharing by guiding the selection of hunting sites. Posts were also used by participants to encourage one another and share negative attitudes about lionfish. Community-based groups are challenged by limited resources, however social-media networks may facilitate communication among participants in ways that help motivate, coordinate and direct group activity. [ABSTRACT FROM AUTHOR]

The Mediterranean region is, by far, a prime travel destination, having hosted more than 330 million tourists in 2016, mostly for seaside holidays. A greatly increased influx of thermophilic Red Sea species, introduced through the Suez Canal in a process referred to as Lessepsian invasion (in honor of Ferdinand de Lesseps who instigated the building of the Suez Canal), have raised awareness among scientists, medical personnel, and the public, of health risks caused by some venomous and poisonous marine species. The main species of concern are the poisonous Lagocephalus sceleratus, and the venomous Plotosus lineatus , Siganus luridus , Siganus rivulatus , Pterois miles , Synancea verrucosa, Rhopilema nomadica, Macrorhynchia philippina and Diadema setosum. Recognizing that the main factors that drive the introduction and dispersal of Red Sea biota in the Mediterranean, i.e., Suez Canal enlargements and warming seawater, are set to increase, and international tourist arrivals are forecasted to increase as well, to 500 million in 2030, an increase in intoxications and envenomations by alien marine species is to be expected and prepared for. • Non-indigenous marine species (NIS) have been introduced from the Red Sea into the Mediterranean Sea through the Suez Canal. • A surge of in the number of venomous and poisonous NIS over the past 40 years was noted in the Mediterranean Sea. • Some of them present highly toxic properties and cause human intoxications and deaths. • Several factors (as climate change and modifications of the canal) converge to increase the phenomenon. • As population around the Mediterranean Sea will increase a rise of human intoxications is to be expected and prepared for. [ABSTRACT FROM AUTHOR]