The Sawtail Grouper (Mycteroperca prionura) is a serranid species endemic to the Gulf of California. Notably, very little is known about its ecology. Although M. prionura is rarely observed by scuba divers, it is thought this species prefers deep (30–50 m) rocky reef habitats containing gorgonians or black corals. Mycteroperca prionura is categorized as Data Deficient on the Red List of the International Union for Conservation of Nature (IUCN). Therefore, any observations of its distribution and habitat improve our understanding of the ecology of this elusive species. In the dataset of an 18-year historical monitoring program in Bahía de La Paz, located in the southern Gulf of California, records of M. prionura were rare. However, during field surveys conducted in 2023 and 2024 at La Gaviota Island, which hosts patches of Black Coral (Antipathes galapagensis) at 15–20 m depth, we regularly observed M. prionura juveniles in close association with colonies of A. galapagensis. Juvenile M. prionura were consistently observed sheltering among A. galapagensis branches, indicating that the structural complexity provided by black corals may offer critical refuge and nursery habitat.
Ascidians are key components of benthic marine communities worldwide. They contribute to biofouling and increase the structural complexity of benthic habitats by providing substrate for other organisms. Despite their ecological relevance, the ascidian fauna of the Colombian Caribbean remains poorly documented. We provide the first confirmed record of the colonial ascidian Clavelina oblonga Herdman, 1880 in Colombia, based on an integrative approach that combined morphological examination with DNA barcoding of the mitochondrial cytochrome oxidase subunit I (COI) gene. Specimens were collected from artificial substrates, including concrete structures, metallic pilings, and submerged ropes at depths of 0.5–2.0 m within a marina in the Atlántico Department on the Caribbean coast of Colombia. The presence of this species may represent either an overlooked native population or human-mediated dispersal associated with maritime traffic. These findings highlight the importance of sustained regional monitoring and the use of molecular tools to improve the documentation of ascidian diversity.
We present a biomass-dynamic bioeconomic model that integrates economic aspects and guidelines for the management of the Red Octopus (Octopus maya) fishery, propose economic reference points, and incorporate economic considerations into harvest control rules (HCRs). This framework allows for the consequences of alternative management actions to be evaluated within a probabilistic context. To develop the biomass-dynamic bioeconomic model, we employed a framework based on the Gordon-Schaefer model (Gordon 1954) without assuming equilibrium (constant stock size). Instead of fishing effort, the proposed model includes the annual cost per ton and is formulated in terms of biomass. We also established economic reference points, including a limit point based on bioeconomic equilibrium and a target point based on net profit at maximum sustainable yield (ΠMSY). These reference points were incorporated into the HCRs, along with management actions that are triggered when the fishery approaches each threshold. A Kobe plot indicated that overfishing occurred between 2009 and 2012 and confirmed that the O. maya stock was overfished in 2013. Accordingly, the HCRs recommend reducing fishing mortality. The model projections suggested that harvesting at 90% of the fishing mortality at maximum sustainable yield (FMSY) would allow biomass to recover to that at maximum sustainable yield (BMSY) in the medium term. The median of the posterior distribution of the bioeconomic model for net profit in 2018 was estimated at MX$428.8 million. The probability of the net profit being zero at a harvest rate of 0.9FMSY was zero. Additionally, the probability that net profit was below ΠMSY in 2018 was 0.61.
. In marine fish farming, the use of anesthetics is necessary to reduce the stress associated with routine procedures, such as capturing, handling, and obtaining biometric measurements. The objective of this study was to determine the minimum effective concentration of 3 anesthetic agents: clove oil, tricaine methanesulfonate (MS-222), and 2-phenoxyethanol. Each anesthetic was evaluated in 9 juvenile Pacific White Snook (Centropomus viridis) at different concentrations. The efficacy criteria considered were the induction time to deep anesthesia (stage III), within a duration of less than 180 s, and the recovery time (RT), no greater than 300 s. In addition, the survival of juveniles was evaluated during the experimental period and for 72 h after exposure to the anesthetics. The minimum effective concentrations were determined to be between 50-75 mg & centerdot;L-1 for clove oil, 125 mg & centerdot;L-1 for MS-222, and 500 & micro;g & centerdot;L-1 for 2-phenoxyethanol, with no visible adverse effects. Inverse correlations were observed between the anesthetic concentrations and induction time (stage III); however, only the clove oil concentration showed a positive correlation with the RT. No mortality was observed during exposure to the anesthetic agents or during the 72 h following the experiment at any of the evaluated concentrations of each anesthetic.
Atlantic Bluefin Tuna (Thunnus thynnus) aquaculture has developed rapidly in recent years, making it necessary to discriminate between specimens derived from aquaculture (captive-reared) and those derived from fisheries (wild-caught). In this study, a method based on the chemical composition of discard tissues (gills and bones) in 3 batches of juvenile T. thynnus (tank-cultured on land, cage-reared in the sea, and wild-caught) was assessed. The concentrations of 11 macro- and micro-elements (i.e., Ca, Fe, K, Mg, Na, P, S, Cu, Mn, Zn, and Sr) were determined and evaluated using an analysis of variance (ANOVA) and 2 multivariate tests, namely a principal component analysis (PCA) and discriminant canonical analysis (DCA). The best results were obtained from the gills and from the batch corresponding to the wild-caught specimens. However, the results were not robust enough to establish any specific pattern that would facilitate the identification of the origin of T. thynnus specimens.
