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.
Shallow marine ecosystems with extensive communities of submerged aquatic vegetation, including seagrasses and macroalgae, are found along the northern coast of the Yucat & aacute;n Peninsula. This study describes the geomorphological complexity of the nearshore seafloor in Yucat & aacute;n, Mexico, and its association with submerged aquatic vegetation communities, constituting the first effort of its kind in this region. This work is relevant because ecological interactions between the seafloor and its inhabitants define the spatial structure of ecosystems, as well as ecological processes, many of which provide benefits to human society. The objectives of this study were to: (1) spatially delineate discrete geomorphological units (structures and zones) based on their depth, slope, and aspect; (2) describe the relative abundance of major groups of submerged aquatic vegetation (seagrasses, green algae, red algae, brown algae, and algal turf); and (3) assess the association between geomorphology and the presence of the vegetation groups under study. This information establishes a baseline for biological, ecological, and oceanographic analyses of the coastal marine ecosystems in southeastern Mexico. In addition, the results of this study are crucial for decision-making related to coastal development, adaptive management, and environmental conservation monitoring, and provide a foundation for functional ecosystem assessment studies.
El conocimiento sobre los aspectos ecológicos de las paralarvas de cefalópodos es esencial para comprender la composición y dinámica de sus poblaciones, así como para identificar temporadas y zonas de desove. En el norte del Pacífico colombiano (NPC) los estudios sobre esta primera etapa de vida son escasos. Este estudio tuvo como propósito establecer la composición taxonómica de las paralarvas del ambiente nerítico del NPC, cuantificar su abundancia y describir su variación espacio-temporal. Se analizaron 315 muestras de zooplancton colectadas mediante arrastres superficiales entre enero y noviembre de 2022 en 3 sectores. Se encontraron 102 paralarvas en el 16.5% de las muestras, y se clasificaron en 4 familias: Loliginidae, Octopodidae, Ommastrephidae y Ancistrocheiridae. Se reporta por primera vez la presencia de paralarvas de calamares loligínidos y del Pulpo de los Changos (Octopus cf. mimus) en esta región. Los valores más altos de abundancia se registraron en marzo (>6 Pl·1,000 m–3) y coincidieron con el periodo de surgencia, lo que sugiere una sincronía entre los eventos reproductivos y el aumento en la productividad biológica que favoreció la supervivencia de las paralarvas. La distribución de los grupos más representativos estuvo influenciada por el comportamiento ecológico de cada familia y las características geomorfológicas de cada sector. Octopodidae predominó en el norte y centro del NPC, donde destacan fondos rocosos y la plataforma continental es estrecha, mientras que Loliginidae se encontró hacia el sur, donde la plataforma es más amplia y predominan playas arenosas. La presencia de estadios tempranos de grupos de interés comercial sugiere la importancia del NPC como zona de actividad reproductiva de estos cefalópodos y resalta la necesidad de profundizar en su biología reproductiva y ecología. Estos hallazgos sientan las bases para entender los patrones de variación temporal en la abundancia de paralarvas en ambientes neríticos del Pacífico Oriental Tropical.
En la costa occidental de la Península de Baja California se han registrado 5 especies de Caulerpa consideradas como parte del elenco florístico regional; sin embargo, a finales de 2023 se detectó en la Laguna Ojo de Liebre, en las costas del Pacífico de Baja California Sur, la presencia de Caulerpa okamurae, cuya abundancia se incrementó notablemente durante 2024-2025. La macroalga se adhiere a los sistemas de cultivo de ostión, incrementa los costos de limpieza y amenaza praderas de pastos marinos y otros hábitats, con posibles efectos sobre recursos pesqueros. Distinguir entre poblaciones criptogénicas, no nativas e invasoras es clave en la investigación sobre la introducción de especies, pues una especie se considera invasora cuando su presencia amenaza la biodiversidad, la economía o la salud. En México existen lineamientos y una estrategia nacional para prevenir, detectar y controlar estas especies. En este trabajo se presenta el primer registro de una población de C. okamurae en las costas del Pacifico mexicano, a partir de la evidencia morfológica de ejemplares recolectados en Laguna Ojo de Liebre, en ausencia de registros previos en México. La confirmación de este hallazgo se suma a las 16 macroalgas introducidas ya documentadas en el Pacífico mexicano, la mayoría de las cuales provienen de Japón y Corea y cuya propagación está asociada al tráfico marítimo y la acuicultura. Ante la introducción y potencial establecimiento de C. okamurae en la Laguna Ojo de Liebre, es imprescindible implementar programas de monitoreo continuos y rigurosos que permitan determinar con precisión su distribución espacio-temporal.
Las comunidades microbianas en ambientes hipersalinos son clave en los ciclos biogeoquímicos y la productividad ecológica. Este es el primer estudio que caracteriza la composición, estructura y potencial metabólico de la comunidad procariota en la columna de agua de la Laguna Ojo de Liebre (Baja California Sur, México), un ecosistema hipersalino con relevancia ecológica y socioeconómica. A partir de la información obtenida de 4 campañas de muestreo (2021-2022) en 18 estaciones, analizamos variables físicoquímicas (salinidad, temperatura y densidad) y secuenciamos la región V4-V5 del gen 16S ARNr. Los datos se procesaron con QIIME2, y se infirió el metabolismo mediante PICRUSt2. La comunidad estuvo dominada por Actinobacteriota, Bacteroidota, Cyanobacteriota, Pseudomonadota y Verrucomicrobiota, con diferencias espaciotemporales vinculadas a gradientes de temperatura (r² = 0.77, P = 0.001) y salinidad (r² = 0.39, P = 0.01). Los taxones raros (<1% de abundancia relativa), como Thermoanaerobaculales y Desulfobacterota, contribuyeron a la diversidad, especialmente en noviembre. La inferencia metabólica reveló rutas significativas (P < 0.05), como la biosíntesis de vitamina B6, la degradación de quitina y la reducción de nitrato, lo que sugiere roles en los ciclos biogeoquímicos y la adaptación a condiciones extremas. La estructura de la comunidad procariota en la laguna respondió a variaciones fisicoquímicas, con un núcleo taxonómico estable y taxones raros que incrementaron la diversidad bajo condiciones específicas. El potencial metabólico inferido resaltó su participación en procesos biogeoquímicos y su capacidad para degradar compuestos orgánicos complejos. Estos resultados establecen una línea base para entender la dinámica microbiana en sistemas hipersalinos y su impacto en la funcionalidad ecosistémica.
El blanqueamiento coralino es principalmente causado por estr & eacute;s t & eacute;rmico, ya que el aumento de temperatura genera olas de calor cada vez m & aacute;s frecuentes e intensas. Adem & aacute;s del incremento de temperatura, el aporte de sedimentos en el Sistema Arrecifal Veracruzano (SAV) podr & iacute;a incrementar el estr & eacute;s y, con ello, la susceptibilidad de los corales al blanquea-miento. Este trabajo evalu & oacute; 2 arrecifes del SAV en 2 escalas de tiempo: (1) a corto plazo (2022 al 2023), mediante el & iacute;ndice de respuesta al blanqueamiento (IRB) para evaluar la recupera-ci & oacute;n de 104 colonias de corales escleractinios con una escala de 1 a 5, y (2) a mediano plazo (2008 al 2021), por medio del & iacute;ndice de coral (IC) para evaluar la salud de la comunidad coralina con una escala de 1 a 6. Valores altos de los & iacute;ndices reflejan un mejor estado de los corales. Se relacion & oacute; el n & uacute;mero de colonias blanqueadas con valores de degree heating week (DHW) y tasas de sedimentaci & oacute;n en ambos periodos. Se obtuvo que los grados de calor acumulado fueron la causa principal de los eventos de blanqueamiento, mientras que los sedi-mentos no tuvieron una influencia directa. En 2022 la prevalencia de blanqueamiento fue de 17% con valores de 5 DHW, siendo Montastraea cavernosa, Siderastrea siderea, Siderastrea stellata y Colpophyllia natans las especies m & aacute;s afectadas. Sin embargo, la mayor & iacute;a exhibieron una pigmentaci & oacute;n creciente dentro de los primeros 5 meses, con valores del IRB de 5 y 6. Durante el periodo de 2008 a 2021, la salud de las comunidades coralinas se clasific & oacute; como buena, con valores del IC de 3.8 y 3.6. Los resultados ilustran que los corales escleractinios han sido resilientes a los eventos de blanqueamiento bajo las condiciones del SAV, resaltando la necesidad de continuar con estudios in situ de las especies susceptibles en este estudio.
Coral reefs are highly diverse ecosystems that provide various environmental services; however, they remain highly threatened. Assessing the health and trends of coral reefs is vital to establishing management strategies that contribute towards their conservation and recovery. One way of contributing to this objective is through monitoring indicators of reef health. In this context, the present study focused on evaluating the health of 4 reef systems located in 2 extensive regions of Mexico: the southwestern Gulf of Mexico (SGM) and the Mexican Caribbean (MC), using the Reef Health Index (RHI). Fieldwork was conducted on 11 reefs in October 2022 in the SGM and in May 2023 in the MC. Data were collected using 5 to 6, 50 x 2 m transects per site, followed by video transects of 50 x 0.50 m to record benthic organisms along the transect. An average RHI score of 3.50 (considered "good") was obtained for SGM reefs, while for MC reefs, the average RHI score was 2.50 (considered "poor"). These results suggest that, according to the RHI criteria, SGM reefs present a better state of health than their MC counterparts. This difference was mainly influenced by the lower coral cover and higher macroalgae cover associated with the coral-algal phase shift, likely resulting from the rapid coastal development observed along the MC coasts. Lastly, for the SGM, this evaluation represents the first reef health assessment for the Lobos-Tuxpan Reef System Flora and Fauna Protection Area using a rating system coupled to ecologic indicators such as the RHI.
The croaker Umbrina xanti is a commercially important species off the coast of Jalisco. However, as is the case with most of the country's fisheries, information on its life history is very limited. For this reason, the objective of this study was to analyze the length at sexual maturity, the reproductive season, and the microscopic description of the gonads, among other aspects. Organisms were collected from 1998 to 2008 using gillnets by artisanal fisheries operating in the central Mexican Pacific. The gonadosomatic index (GSI), sexual maturity stages, oocyte diameter, condition factor, and sex ratio were analyzed monthly. Gonad histology was performed, and average length at maturation was estimated. A total of 1,202 organisms were captured, measuring between 17.9 and 42.3 cm total length (TL). The number of females was greater than that of males (1:0.88). The highest percentages of mature individuals occurred in February and from April to May. The highest values for the IGS were recorded from January to May. The largest oocyte diameters occurred from March to June. Oocyte development was asynchronous, and the testis presented unrestricted lobular development. The average length at maturation for females was 27.37 cm, and for males it was 28.78 cm. Because the average lengths at sexual maturity were shorter than the average length, we can conclude that more than 50% of the organisms captured by commercial fisheries had undergone a reproductive event.
