Canibalismo en ctenosaura pectinata (squamata: iguanidae) en el parque nacional isla Isabel, Nayarit, México

ABSTRACT. Ctenosaura pectinata is a lizard endemic to Mexicoand, it is considered threatened according to NOM-059-2010-SEMARNAT. Photographic evidence shows the first record of cannibalism of C. pectinata at Isla Isabel National Park.RESUMEN. Ctenosaura pectinata es una iguana endémica de México y está considerada como amenazada de acuerdo con la Norma NOM-059-2010-SEMARNAT. Las evidencias fotográficas muestran el primer registro de canibalismo de C. pectinata en el Parque Nacional Isla Isabel.

Diversidad taxonómica de lagartijas (Squamata: Lacertilia) asociada a cuatro tipos de vegetación de la sierra El Cuale, Jalisco, México

The lizard composition and diversity of lizards fauna are influenced by vegetation types, because these determine the physical and environmental structure of their habitats. The aim of this study was to determine and analyze the taxonomic diversity of lizards from Sierra El Cuale conservation priority area in Jalisco, Mexico, associated with four vegetation types: tropical semideciduous forest (BT), oak forest (BE), pine-oak forest (BPE), and pine forest (BP). Monthly sampling was carried out from July 2015 to June 2016. A total richness of 12 species was recorded in the study area: nine species in BE, eight in BT, six in BPE, and six in BP. The species accumulation curves showed that more sampling effort is required to characterize the lizard community as a whole. The species Anolis nebulosus, Sceloporus melanorhinus, and S. utiformis were observed in the four types of vegetation, but Basiliscus vittatus, Gerrhonotus liocephalus, and Scincella assatus only in one each. A nonmetric multidimensional scaling analysis (NMDS) identified two groups according to the presence of lizard species and seasons (rainy and dry): BPE-BP, and BT-BE. The average taxonomic distinctness (Δ+) and the species richness were high in the rainy season. The results of this study show that the lizard species richness in Sierra El Cuale is linked to vegetation type variety. On the other hand, the comparative analysis of Δ+ between Sierra El Cuale and Biosphere Reserves of Chamela-Cuixmala and Manantlán, showed that Sierra El Cuale has an important role in the contribution of regional lizard diversity.La composición y diversidad de las lagartijas son influenciadas por el tipo de vegetación, debido a que éste determina la estructura física y ambiental de sus hábitats. El objetivo de este estudio fue determinar y analizar la diversidad taxonómica de las lagartijas del área prioritaria de conservación Sierra El Cuale, Jalisco, México, asociada a cuatro tipos de vegetación: bosque tropical subcaducifolio (BT), bosque de encino (BE), bosque de pino-encino (BPE) y bosque de pino (BP). Se realizaron muestreos mensuales entre julio de 2015 y junio de 2016. Se registró una riqueza total de 12 especies en el área de estudio: ocho en BT, nueve en BE, seis en BPE y seis en BP. Las curvas de acumulación de especies mostraron que se requiere más esfuerzo de muestreo para caracterizar en su totalidad a la comunidad de lagartijas. Anolis nebulosus, Sceloporus melanorhinus y S. utiformis se observaron en los cuatro tipos de vegetación, pero Basiliscus vittatus, Gerrhonotus liocephalus y Scincella assatus solo en uno. Un análisis de escalamiento multidimensional no métrico (NMDS) identificó dos grupos según la presencia de especies de lagartijas y estaciones del año (lluvias y seca): BPE-BP y BT-BE. La distintividad taxonómica promedio (Δ+) y la riqueza de especies fueron altas en la estación lluviosa. Los resultados de este estudio muestran que la riqueza de especies de lagartijas en la Sierra El Cuale está vinculada a la variedad de tipos vegetación. Por otro lado, el análisis comparativo de la Δ+ entre la Sierra El Cuale y las Reservas de la Biosfera de Chamela-Cuixmala y Manantlán, mostró que la Sierra El Cuale tiene un papel importante en la contribución regional de la diversidad de lagartijas

Temporal oceanographic variation using satellite imagery data in the central Mexican Pacific convergence zone

The oceanographic variation of the central Mexican Pacific (CMP) is mainly driven by the California Current and the Mexican Coastal Current, which generate a convergence zone. Little information is available regarding changes in oceanographic variables at the mesoscale level in the CMP. Therefore, this study characterized 6 oceanographic variables (sea surface temperature, chlorophyll concentration [Chl], primary productivity [PP], diffuse attenuation coefficient [K490], and particulate inorganic/organic carbon concentration [PIC, POC]) in the CMP from 2010 to 2017 and their relationships with El Niño/Southern Oscillation (ENSO). The variables were standardized to monthly pixel values of 0.08 latitude degrees, and the study area covered 48,846.48 km2. Friedman tests were used to compare the temporal variation in the variables, while Spearman correlations were used to evaluate the relationship between each variable and the Multivariate ENSO Index (MEI). A cross-correlation analysis was performed to determine the temporal lag between the oceanographic variables and the MEI. The cyclicity of the variation in the CMP was determined by spectral analysis. All variables showed significant differences between months and years. Two seasons defined by temperature were also detected: a cold season (December–June), in which high values of these variables were observed, and a warm season (July–November), in which low values of these variables were observed. No variables were correlated with the MEI; however, a 4-month time lag was identified between the variables and the MEI. The cyclicity of the variables corresponded to the cold and warm seasons. The cold phase of ENSO increased the values of PP, Chl, and K490 up to 4 times compared to those of other years. Taken together, the observed variation in oceanographic conditions makes the CMP one of the most dynamic coastal regions of the Mexican Pacific

Reef Fish Assemblage in Two Insular Zones within the Mexican Central Pacific

Reefs fishes are sensitive to environmental changes, particularly in areas such as the Mexican Central Pacific (MCP), which has a high environmental variability favored by currents. This study assesses the temporal variation in ecological indicators of fishes in Marietas (MI) and Isabel islands (II) in the MCP during 2010–2017. Overall, 118 species were recorded at MI and 95 in II. The highest abundance was recorded in 2013 at MI, and in 2015 at II, with an observed sample coverage > 0.79 for all years. MI showed higher annual taxonomic distinctness and richness than II. Annual biomass and assemblages were different between years and islands. The changes in both islands’ community structure were influenced by ENSO events. A high proportion of the dissimilarity among years is represented in 10 species, and the difference among years for each island is given by rare species. Annually, community indicators (Δ+, q = 1, and q = 2) and physicochemical factors were not related except for q = 0 and the chlorophyll concentration; this is due to the inter-annual variation within the area. The variation in fish communities on both islands results from mesoscale phenomena that have a different effect on each island due to the characteristics of their shelf and oceanography

Species composition, richness, and distribution of marine bivalve molluscs in Bahía de Mazatlán, México

We describe the composition and distribution of bivalve molluscs from the sandy and rocky intertidal and the shallow subtidal environments of Bahía de Mazatlán, México. The bivalve fauna of the bay is represented by 89 living species in 28 families, including 37 new records and four range extensions: Lithophaga hastasia, Adula soleniformis, Mactrellona subalata, and Strigilla ervilia. The number of species increases from the upper (44) and lower intertidal (53) to the shallow subtidal (76), but only 11 (17%) have a wide distribution in the bay (i.e., found in all sampling sites and environments). The bivalve assemblages are composed of four main life forms: 27 epifaunal species, 26 infaunal, 16 semi-infaunal, and 20 endolithic. A taxonomic distinctness analysis identified the sampling sites and environments that contribute the most to the taxonomic diversity (species to suborder categories) of the bay. The present work increased significantly (31%) to 132 species previous inventories of bivalves of Bahía de Mazatlán. These species represent 34% of the bivalve diversity of the southern Golfo de California and approximately 15% of the Eastern Tropical Pacific region

Species composition, richness, and distribution of marine bivalve molluscs in Bahía de Mazatlán, México

We describe the composition and distribution of bivalve molluscs from the sandy and rocky intertidal and the shallow subtidal environments of Bahía de Mazatlán, México. The bivalve fauna of the bay is represented by 89 living species in 28 families, including 37 new records and four range extensions: Lithophaga hastasia, Adula soleniformis, Mactrellona subalata, and Strigilla ervilia. The number of species increases from the upper (44) and lower intertidal (53) to the shallow subtidal (76), but only 11 (17%) have a wide distribution in the bay (i.e., found in all sampling sites and environments). The bivalve assemblages are composed of four main life forms: 27 epifaunal species, 26 infaunal, 16 semi-infaunal, and 20 endolithic. A taxonomic distinctness analysis identified the sampling sites and environments that contribute the most to the taxonomic diversity (species to suborder categories) of the bay. The present work increased significantly (31%) to 132 species previous inventories of bivalves of Bahía de Mazatlán. These species represent 34% of the bivalve diversity of the southern Golfo de California and approximately 15% of the Eastern Tropical Pacific region

Coral Recovery in the Central Mexican Pacific 20 Years after the 1997–1998 El Niño Event

El Niño–Southern Oscillation (ENSO) events are increasing globally in both frequency and strength, and they can elicit coral bleaching events. The 1997–1998 ENSO caused mass coral mortality with a 96% decline in live coral cover along the Central Mexican Pacific. However, in recent years, these sites have shown signs of recovery. We used data collected in 1997 and 2015–2017 to evaluate the coral recovery in this region and coral cover levels have now reached 50% of their pre-1997–1998 El Niño values. Furthermore, a strong 2015–2016 ENSO event did not significantly affect the live coral cover, potentially demonstrating that the local corals have acclimatized or even adapted to higher temperatures. Even though branching species remain the most abundant morphotype, a PERMANOVA revealed significant changes in the coral assemblage. Collectively, this dataset is testament to the fact that corals within this region are capable of resisting or at least partially recovering from thermal anomalies caused by ENSO events

Upper mesophotic reef fish assemblages at Bahía de Banderas, Mexico

There is no information on the species associated with the mesophotic reefs of Banderas Bay, located in the central Mexican Pacific. This study analysed the reef fish assemblage from three depths (50, 60 and 70 m) in three sampling sites of the southern submarine canyon of the Bay: Los Arcos, Bajo de Emirio and Majahuitas. Several analyses were performed to test the hypothesis that there are important differences in fish abundance and species composition between sites and depths. Twenty-two species of bony fishes grouped in 14 families were recorded. PERMANOVA results showed that there were no significant differences in fish diversity parameters between sites, indicating a certain uniformity in their distribution. However, nine species were exclusive to one site and depth (five singleton species with only one individual recorded and four unique species recorded only once). On the other hand, there were significant differences between depths, mainly between 50 and 70 m. Diversity decreases with depth and species composition changes. SIMPER, Shade Plot and NMDS analysis show the most representative species at each depth, with at least half of the species (11) recorded only at 50 m and four species at the deeper levels (60 - 70 m). The observed assemblage includes several of the most caught species in the shallow water artisanal fishery, which is the most traditional and common type of fishery in the Bay. In addition, the Pomacanthus zonipectus (Cortés angelfish) is of particular interest, as it has a special protection status in the official Mexican standard (NOM-059-SEMARNAT, 2010) due to its use as an ornamental species in aquaria. We hypothesised that the mesophotic zone may serve as a refuge for these fishes, so we propose that the information obtained is an important basis for new research aimed at the sustainable management of fisheries in the area

Gamma-diversity partitioning of gobiid fishes (Teleostei Gobiidae) ensemble along of Eastern Tropical Pacific: Biological inventory, latitudinal variation and species turnover

Gobies are the most diverse marine fish family. Here, we analysed the gamma-diversity (γ-diversity) partitioning of gobiid fishes to evaluate the additive and multiplicative components of α and β-diversity, species replacement and species loss and gain, at four spatial scales: sample units, ecoregions, provinces and realms. The richness of gobies from the realm Eastern Tropical Pacific (ETP) is represented by 87 species. Along latitudinal and longitudinal gradients, we found that the γ-diversity is explained by the β-diversity at both spatial scales, ecoregions and provinces. At the ecoregion scale, species are diverse in the north (Cortezian ecoregion) and south (Panama Bight ecoregion) and between insular and coastal ecoregions. At the province scale, we found that the species turnover between the warm temperate Northeast Pacific (WTNP), Tropical East Pacific (TEaP) and the Galapagos Islands (Gala) was high, and the species nestedness was low. At the ecoregion scale, historical factors, and phylogenetic factors have influenced the hotspots of gobiid fish biodiversity, particularly in the Cortezian, Panama Bight and Cocos Island ecoregions, where species turnover is high across both latitudinal and longitudinal gradients. At the provincial level, we found that the contributions of the β-diversity from north to south, in the WTNP, TEaP and Gala were high, as result of the high number of unique species. Species turnover was also high at this scale, with a low contribution from species nestedness that was probably due to the low species/gene flow within the provinces. These results highlight the importance and successful inclusion of a cryptobenthic fish component in ecological and biogeographical studies.</p