Gut throughput rate and satiation of the invasive Lionfish (Pterois volitans) and its potential impact on an endemic, endangered Labrid fish Halichoeres socialis

The invasive Indo-Pacific Lionfish Pterois volitans has been recognized as a severe threat to indigenous fish species on Caribbean reefs. Previous studies have identified an extensive variety of Caribbean fishes in the stomachs of lionfish, but few have tried to quantify the impact these invaders could have on endemic or threatened species. The threatened Labrid fish Halichoeres socialis has been identified as the primary component of lionfish diet in Belizean lagoonal reef systems. This study aims to answer two questions: what is the average maximum number of prey-fish a lionfish can consume in one sitting, and at what rate can these lionfish pass a meal of three prey fish completely? To test lionfish satiation, the subjects were fed as many Pseudohemiculter dispar (a commercially available surrogate) as they could eat within a fifteen-minute window. During the digestion rate experiment, lionfish were fed three similarly sized P. dispar and allowed to digest in 3, 6, 9, 12, 15, 19, and 24 hour blocks. From observing prey throughput under near optimal laboratory conditions, the maximum potential impact of lionfish on native populations of Caribbean reef dwelling fishes can be estimated. Given the volume and mass of prey items consumed in this study between 593 and 4658 individual H. socialis could be consumed by a single lionfish in one year. Coupled with further investigation into H. socialis stock numbers, lionfish (P. volitans) could be considered a potentially immanent threat to fishes that exhibit body morphometrics like those of H. socialis at any stage of their life-history

An Integrated Assessment of the Introduction of Lionfish (Pterois volitans/miles complex) to the Western Atlantic Ocean.

Lionfish (Pterois volitans/miles complex) are venomous coral reef fishes from the Indian and western Pacific oceans that are now found in the western Atlantic Ocean. Adult lionfish have been observed from Miami, Florida to Cape Hatteras, North Carolina, and juvenile lionfish have been observed off North Carolina, New York, and Bermuda. The large number of adults observed and the occurrence of juveniles indicate that lionfish are established and reproducing along the southeast United States coast. Introductions of marine species occur in many ways. Ballast water discharge, a very common method of introduction for marine invertebrates, is responsible for many freshwater fish introductions. In contrast, most marine fish introductions result from intentional stocking for fishery purposes. Lionfish, however, likely were introduced via unintentional or intentional aquarium releases, and the introduction of lionfish into United States waters should lead to an assessment of the threat posed by the aquarium trade as a vector for fish introductions. Currently, no management actions are being taken to limit the effect of lionfish on the southeast United States continental shelf ecosystem. Further, only limited funds have been made available for research. Nevertheless, the extent of the introduction has been documented and a forecast of the maximum potential spread of lionfish is being developed. Under a scenario of no management actions and limited research, three predictions are made: ● With no action, the lionfish population will continue to grow along the southeast United States shelf. ● Effects on the marine ecosystem of the southeast United States will become more noticeable as the lionfish population grows. ● There will be incidents of lionfish envenomations of divers and/or fishers along the east coast of the United States. Removing lionfish from the southeast United States continental shelf ecosystem would be expensive and likely impossible. A bounty could be established that would encourage the removal of fish and provide specimens for research. However, the bounty would need to be lower than the price of fish in the aquarium trade (~$25-$50 each) to ensure that captured specimens were from the wild. Such a low bounty may not provide enough incentive for capturing lionfish in the wild. Further, such action would only increase the interaction between the public and lionfish, increasing the risk of lionfish envenomations. As the introduction of lionfish is very likely irreversible, future actions should focus on five areas. 1) The population of lionfish should be tracked. 2) Research should be conducted so that scientists can make better predictions regarding the status of the invasion and the effects on native species, ecosystem function, and ecosystem services. 3) Outreach and education efforts must be increased, both specifically toward lionfish and more generally toward the aquarium trade as a method of fish introductions. 4) Additional regulation should be considered to reduce the frequency of marine fish introduction into U.S. waters. However, the issue is more complicated than simply limiting the import of non-native species, and these complexities need to be considered simultaneously. 5) Health care providers along the east coast of the United States need to be notified that a venomous fish is now resident along the southeast United States. The introduction and spread of lionfish illustrates the difficulty inherent in managing introduced species in marine systems. Introduced species often spread via natural mechanisms after the initial introduction. Efforts to control the introduction of marine fish will fail if managers do not consider the natural dispersal of a species following an introduction. Thus, management strategies limiting marine fish introductions need to be applied over the scale of natural ecological dispersal to be effective, pointing to the need for a regional management approach defined by natural processes not by political boundaries. The introduction and success of lionfish along the east coast should change the long-held perception that marine fish invasions are a minimal threat to marine ecosystems. Research is needed to determine the effects of specific invasive fish species in specific ecosystems. More broadly, a cohesive plan is needed to manage, mitigate and minimize the effects of marine invasive fish species on ecosystems that are already compromised by other human activities. Presently, the magnitude of marine fish introductions as a stressor on marine ecosystems cannot be quantified, but can no longer be dismissed as negligible. (PDF contains 31 pages

Pterois (Oken, 1817) (Scorpaeniformes, Scorpaenidae) Genusunun Bulunması Üzerine: Karaib Denizinde İstila Alanının Genişlemesi ve Los Frailes Takımadaları İçin Yayınlanan İlk Kayıt

The present work reports the presence of Lionfish (Pterois volitans) in Los Frailes Archipelago, Venezuela. This is the first published record of Lionfish presence for this location and the extension of their invasive range to the South-East of the Caribbean Sea.Bu çalışma, bir İskorpit balığı türü olan Pterois volitans, Venezuela Los Frailes takımadalarındaki varlığını bildirmektedir. Karayip Denizi’nin güneybatı sınırındaki bu bölge için Pterois volitans’ın varlığı ve istilacı yayılım alanını genişletmesi açısından yayınlanmış ilk kayıttır.Fil: Callicó Fortunato, Roberta Glenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Unidad Ejecutora de Investigaciones En Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones En Producción Animal; ArgentinaFil: Avigliano, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Pque. Centenario. Unidad Ejecutora de Investigaciones En Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones En Producción Animal; Argentin

Potential Range Expansion of the Invasive Lionfish in the Western Atlantic Ocean

Lionfish (Pterois volitans) are an invasive, predatory fish native to the reefs of the Indo-Pacific. In the mid-1980s, lionfish were introduced off the coast of Miami, FL and have since transformed many of the reef ecosystems throughout the Western Atlantic Ocean. Although lionfish are found year-round as far north as Cape Hatteras, NC, they are confined to the warm Gulf Stream during winter months. Seasonal inshore expansion is possible in the summer, and further poleward expansion is limited by cold bottom-water temperatures in winter. Here, I use an ensemble of 17 different climate models to project lionfish habitat by the year 2100. Climate models were statistically downscaled using an existing Regional Ocean Modeling System, permitting a high-resolution (7-by-7 km) projection of bottom-water temperatures across the Western Atlantic Ocean. I compared these projections to the lower temperature thresholds of lionfish feeding and mortality, previously estimated to be 16°C and 10°C, respectively. Under the business-as-usual climate change scenario (RCP 8.5), lionfish habitat is likely to move inshore to the coastlines of the Carolinas, including the Pamlico Sound, NC. The spatial extent of suitable habitat in the South Atlantic Bight is expected to increase 35% by 2100, and seasonal range is expected to expand by 24%. These methods are broadly applicable to other niche models, especially for other hardy, generalist species sensitive to climate change. This work has applications for management and prevention of future lionfish invasions

Biology and ecology of the invasive lionfishes, Pterois miles and Pterois volitans

The Indo-Pacific lionfishes, Pterois miles and P. volitans, are now established along the U.S. southeast coast, Bermuda, Bahamas, and are becoming established in the Caribbean. While these lionfish are popular in the aquarium trade, their biology and ecology are poorly understood in their native range. Given the rapid establishment and potential adverse impacts of these invaders, comprehensive studies of their biology and ecology are warranted. Here we provide a synopsis of lionfish biology and ecology including invasion chronology, taxonomy, local abundance, reproduction, early life history and dispersal, venomology, feeding ecology, parasitology, potential impacts, and control and management. This information was collected through review of the primary literature and published reports and by summarizing current observations. Suggestions for future research on invasive lionfish in their invaded regions are provided

Biología reproductiva de Pterois volitans en la Reserva de la Biosfera Baconao, sur de Cuba

Background: Pterois volitans Linnaeus 1758 is an invasive exotic species established in the Atlantic and Caribbean, threatening the native marine biodiversity. It has led to reduced recruitment and biomass of small reef fish of ecological interest, altering the fish community structure by reducing the number of herbivores. In Cuba, it was first reported in 2007. Goals: This research aims to characterize the reproductive biology of P. volitans in the western part of the Baconao Biosphere Reserve, in southern Cuba. Methods: Sampling was carried out monthly from April 2012 to May 2013 (n = 535 fish). Total length (LT, cm), total mass (MT, g), and weight of the liver, gonads, and abdominal fat were recorded for each individual. To analyze spawning, the gonadosomatic (IG) and hepatosomatic indices (IH) were determined. Results: Mean size and weight of adults were 26.8 cm and 290.9 g, respectively. The size structure revealed that females are dominant in lengths of 22-31 cm, whereas males dominate from 31 cm onwards. The sex ratio was 1:1. IG showed seasonal spawning peaks between March and May 2013. No significant differences were observed amongst monthly means, but IH monthly means and monthly rates of abdominal fat showed significant differences. The size at first maturity was 30.07 cm in males and 26.2 cm in females. Conclusions: The results of this study suggest that the lionfish P. volitans shows an asynchronous reproductive cycle characterized by high gonadal index values during the breeding season and an inverse trend of IH and IF, suggesting that the liver and body fat store nutrients for use in reproduction.Antecedentes: Pterois volitans Linnaeus 1758 es una especie exótica invasora establecida en el Atlántico y el Caribe que amenaza la biodiversidad marina nativa. En consecuencia, su presencia ha reducido el reclutamiento y la biomasa de los peces pequeños del arrecife de interés ecológico, alterando la estructura de la comunidad al reducir el número de herbívoros. En Cuba, se informó de su presencia por primera vez en 2007. Objetivos: Esta investigación tiene como objetivo caracterizar la biología reproductiva de P. volitans en la zona occidental de la Reserva de la Biosfera Baconao, costa sur oriental de Cuba. Métodos: El muestreo se realizó mensualmente de abril de 2012 a mayo de 2013 (n = 535 peces). A cada pez capturado se le registró la longitud total (LT, cm), peso total (MT, g), peso del hígado (g), gónadas (g) y grasa abdominal (g). Para analizar la época de desove, se determinaron los índices gonádico-somático (IG) y hepático-somático (IH). Resultados: La talla promedio fue 26.8 cm con un peso medio de 290.9 g. La estructura poblacional, revela que las hembras son dominantes en longitudes que van desde 22-31 cm y los machos a partir de los 31 cm. La proporción de sexos fue de 1: 1. EL IG mostró picos estacionales de desove, entre (marzo y junio), aunque no se encontraron diferencias significativas entre las medias mensuales, pero sí entre las medias mensuales del IH y el índice de grasa abdominal. La talla de primera madurez se determinó en los machos de 30 cm y en las hembras de 26.2 cm. Conclusiones: Los resultados de este estudio indican que el pez León P. volitans tiene un ciclo reproductivo asincrónico, con altos valores del índice gonadosomático durante el periodo reproductivo y con una tendencia inversa con el IH y el IF, lo que sugiere que el hígado y la grasa del cuerpo contienen nutrientes que se utilizan durante el periodo reproductivo

Comparison of Age and Growth Parameters of Invasive Red Lionfish (\u3ci\u3ePterois volitans\u3c/i\u3e) Across the Northern Gulf of Mexico

Invasive red lionfish (Pterois volitans) have spread rapidly throughout the northern Gulf of Mexico (GOM) partly because of their high growth rate. Red lionfish were collected from the northern GOM across 3 ecological regions from 2012 through 2015. For male and female red lionfish, relationships between weight and total length (TL) were differnt by ecological region. Males acheives a greater mean weight adjusted for TL (333.6 g [standar errer (SE) 3.6]) than females (195.1 g [SE 3.7]). A subsample of 1607 pairs of sagittal otoliths (from 744 males, 716 females, and 147 fish of unknown or undetermined sex) was used to assign ages. Ages ranged from 0.0 to 4.5 years (mean: 1.4 years), and these estimated ages and the dates of capture for specimens confirm the presence of red lionfish in the northern GOM in 2008, 2 years prior to the first detection of this species there. There were differences in age and rowth between sexes within and among ecological regions, with males achieving higher growth rates and larger asympototic lengths than females (all comparions:

Trophic Interactions and Habitat Quality of Invasive Lionfish in the Gulf of Mexico

Lionfish (Pterois volitans and Pterois miles) are one of the most successful marine invaders of all time and pose a threat to native species that inhabit coral reefs, as well as overall reef health. Current management efforts in the invaded Atlantic region revolve around spearfishing to remove lionfish, often limited to 30 m depth. There is evidence that lionfish may seek refuge from fishing pressure in deeper habitat and replenish shallow sites, undermining this management strategy. To investigate the ecological implications of deep lionfish, size, reproductive capability, and diet were examined across a depth gradient for lionfish in the Florida Keys. It was found that size weakly increased with increasing depth and that shallow lionfish had higher reproductive potential. Sex ratios were female-biased in shallow sites. Lionfish are eating a range of teleosts and decapod species, including those of economic importance, and deeper lionfish are eating at a higher trophic level than shallow fish. These results were used to inform the parameters of a bioenergetic-based growth model for lionfish in the Gulf of Mexico. Prey energy density was modified to account for deeper (\u3e30 m) lionfish’s increased consumption of teleost prey compared to shallow counterparts. Bottom temperatures at the locations of potential structured habitat were used to calculate the growth rate potential (GRP) of lionfish regionally and seasonally. There are regional differences in potential habitat that are not reflected in recorded lionfish sightings, and seasonal temperature changes do not limit lionfish growth in the GOM. A GRP model can be a useful tool to identify areas of lionfish growth and inform where management efforts can be focused for removals, particularly for lionfish at depth. This model could also be extended outside of the GOM to provide a management tool for the entirety of the lionfish’s invaded range

Coping with the Lionfish Invasion: can targeted removals yield beneficial effects?

Invasive species generate significant environmental and economic costs, with maintenance management constituting a major expenditure. Such costs are generated by invasive Indo-Pacific lionfish (Pterois spp.) that further threaten already stressed coral reefs in the western Atlantic Ocean and Caribbean Sea. This brief review documents rapid range expansion and potential impacts of lionfish. In addition, preliminary experimental data from targeted removals contribute to debates about maintenance management. Removals at sites off Little Cayman Island shifted the size frequency distribution of remaining lionfish toward smaller individuals whose stomachs contained less prey and fewer fish. Fewer lionfish and decreased predation on threatened grouper, herbivores and other economically and ecologically important fishes represent key steps toward protecting reefs. However, complete evaluation of success requires long-term data detailing immigration and recruitment by lionfish, compensatory growth and reproduction of lionfish, reduced direct effects on prey assemblages, and reduced indirect effects mediated by competition for food. Preventing introductions is the best way to avoid impacts from invasive species and early detection linked to rapid response ranks second. Nevertheless, results from this case study suggest that targeted removals represent a viable option for shifting direct impacts of invasive lionfish away from highly vulnerable components of ecosystems

Distribution and Length Frequency of Invasive Lionfish (Pterois sp.) in the Northern Gulf of Mexico

The purpose of this communication is to document continued spatial expansion of lionfish farther west into the northern Gulf of Mexico. Furthermore, we provide the first length— mass relationships and length frequency information for lionfishes captured within the northern GOM based on data collected as part of a broader on—going study of lionfish life history in this region