Abundancia y ecología trófica del pez león, Pterois volitans, en el Parque Nacional Morrocoy, Venezuela, mar Caribe Sur

La invasión del pez león, Pterois volitans, en la costa Atlántica de los Estados Unidos y el mar Caribe representa una amenaza al funcionamiento del ecosistema marino. En 2010 fue reportado por primera vez en las costas venezolanas, y en 2013 ya era común en zonas arrecifales. El objetivo del presente estudio fue evaluar la abundancia y la ecología trófica del pez león en el Parque Nacional Morrocoy, y comparar su abundancia con la de otras especies nativas. En 2013 se realizaron censos visuales y recolectaron especímenes en diferentes hábitats (arrecifes, praderas de fanerógamas y manglares) y estratos de profundidad (1-3 m, 6-9 m, 12-15 m). Los resultados mostraron una alta variabilidad en la abundancia, con una densidad promedio de 46,30 (± 42,31 DE) peces∙ha-1 en arrecifes, mientras que en praderas de fanerógamas y manglares no se observó la presencia de la especie. Su densidad no difirió entre estratos de profundidad y fue significativamente mayor a la de las especies nativas censadas (familias Muraenidae y Serranidae). Su dieta estuvo compuesta de peces y crustáceos, con una mayor proporción de peces en especímenes de mayor tamaño. Las familias de peces más abundantes dentro del parque, Labridae, Haemulidae y Gobiidae, formaron parte de su dieta. Dadas las características del pez león como depredador generalista, un aumento de su población posiblemente afectaría significativamente la abundancia de peces nativos de las familias más representadas en su dieta, y la estructura y funcionamiento de estos sistemas arrecifales.

Total mercury concentrations in invasive lionfish (Pterois volitans/miles) from the Atlantic coast of Florida

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.

Marine Transcriptomics Analysis for the Identification of New Antimicrobial Peptides

Antimicrobial peptides (AMPs) participate in the immune system to avoid infection, are present in all living organisms and can be used as drugs. Fish express numerous AMP families including defensins, cathelicidins, liver-expressed antimicrobial peptides (LEAPs), histone-derived peptides, and piscidins (a fish-specific AMP family). The present study demonstrates for the first time the occurrence of several AMPs in lionfish (Pterois volitans). Using the lionfish transcriptome, we identified four transcript sequences encoding cysteine-rich AMPs and two new transcripts encoding piscidin-like peptides. These AMPs are described for the first time in a species of the Scorpaenidae family. A functional approach on new pteroicidins was carried out to determine antimicrobial sequences and potential uses, with a view to using some of these AMPs for human health or in aquaculture.

ISOLATION OF PROTEIN FROM THE SPINE VENOM OF PTEROIS VOLITANS FOUND IN THE INDONESIAN OCEAN, USING A HEATING PROCESS, FOR ANTICANCER, ANTIRETROVIRAL, ANTIBACTERIAL, AND ANTIOXIDANT ASSAYS

Objective: This research investigates the antibacterial, anticancer, antioxidant, and antiretroviral activities of the lionfish spine poison extract. Methods: Isolation and purification of the phospholipase A2 (PLA2) protein obtained from the spine poison were conducted through the following stages, including, extraction of the venom by sonication, heating, and purification using gradual saturation levels of ammonium sulfate. Furthermore, the purity and concentration of PLA2 were analyzed using the Lowry test and Marinetti’s method, respectively, while its protein content was ascertained through SDS-PAGE. Toxicity was then evaluated employing the brine shrimp lethality test (BSLT), and its anticancer activity was assessed in human cervical carcinoma cells (HeLa cells). Finally, its antioxidant, antibacterial, and antiretroviral activities were analyzed using the DPPH method, agar diffusion test against Salmonella sp. and E. coli, and SRV-2 and RT-qPCR tests, respectively. Results: The protein demonstrated 37.79% inhibition for anticancer activity, IC50 1312 ppm for antioxidant activity, 98.81%, and 89.28% inhibition of E. coli and Salmonella sp. respectively for antibacterial activity and 98.13% inhibition for antiretroviral activity. Conclusion: It can be concluded that lionfish (Pterois volitans) has the potential to be developed as an antioxidant, anticancer, antibacterial, and antiretroviral agent. Furthermore, the pharmacological activity of its spine venom was determined by isolating PLA2 protein from its extract, using an optimum heating temperature of 70 °C and an ammonium sulfate saturation level of 80%.

Oldest Indo-Pacific Lionfish (Pterois volitans/P. miles) Recorded From the Northwestern Gulf of Mexico

Indo-Pacific lionfish (Pterois volitans/miles) were first detected off the coast of Florida in the 1980s, with aquaria release being the most likely mechanism for introduction. Since then, lionfish have proliferated through the Western Atlantic Ocean, Caribbean Sea, and Gulf of Mexico (GOM). Here, we report the oldest lionfish aged on record in the Western Atlantic, removed from Flower Garden Banks National Marine Sanctuary (FGBNMS) in the GOM. In August 2018, a research expedition removed 745 lionfish from FGBNMS, of which a subset were retained for age and growth estimation. The oldest lionfish was a 10 y old male, with total length 375 mm and weight 805 g. The back-calculated birth date (2008) preceded the first observation of lionfish at FGBNMS by 3 years (2011). It is not well understood if lionfish are having negative impacts at FGBNMS, but this report signifies the importance of continued monitoring and removal efforts of this protected area.

Trophic overlap of lionfish (Pterois volitans) and two native predators (Lutjanus apodus and Cephalopholis cruentata) in the western Caribbean

Impact of invasive species on native biota may be due to predation, competition for space or food, or indirect effects. Lionfish (Pterois volitans), invasive in the western Atlantic, is a voracious generalist predator, so it is expected to have a significant trophic overlap with native fishes of comparable size and habits. The goal of this study was to determine the diets of potential competitors of the lionfish, in particular a grouper, Cephalopholis cruentata (Graysby), and a snapper, Lutjanus apodus (Schoolmaster), and to compare them to the diet of lionfish in Xcalak, southern Mexican Caribbean. Stomach contents were analyzed and electivity and diet overlap were estimated. The trophic overlap between the lionfish and the two putative competitors, especially the grouper, was high, including prey that was consumed by the predators in higher proportion than the relative abundance of the prey in the environment, and probably at the same time of day. Lionfish and grouper shared as important diet items Stegastes sp., Halichoeres sp., Brachyura, and Palaemonidae, and most full stomachs were found during the early morning. The hypothesis of competition between them for particular prey is supported, so we advise to continue the culling programs of lionfish and also to monitor the abundance of the possible native competitors.