In Corozalito beach, Costa Rica, Olive Ridley turtles (Lepidochelys olivacea) nest both solitarily and in arribadas. The predation of solitary nests was monitored from 2008 to 2021, recording date, time, sector of the beach, zone, status of nest (predated or partially predated) and predator when possible. We recorded 4450 predated nests in total (N = 30,148 nesting events); predation rates showed a fluctuating trend, with recent percentages reaching up to 30%, with four distinctive dips in 2010, 2014, 2016 and 2017. The spatial distribution of predated nests along the beach showed significant differences among the sectors regardless of the seasons (Friedman test, chi-squared = 14.778, df = 2, p-value = 0.000), with most predated nests (47.62%) occurring in the northern sectors of the beach. Predators were identified by their tracks and/or direct observations (N = 896, 24.08%). The most conspicuous predators identified were raccoons (55.69%) and black vultures (22.77%). As seen in Corozalito, predation rates have increased in recent years despite established conservation efforts. A comprehensive assessment of all threats towards the overall hatching success for clutches is needed, considering predation during mass nesting events, poaching and beach erosion, among other factors, to fully understand the nesting dynamics occurring in this beach.

Echinoderms are a major group of marine invertebrates that often play integral roles within the marine ecosystem. Studies about their occurrence, abundance, and distribution in Venezuela are focused in the central-eastern coasts; hence the aim of this study is to describe the echinoderm community in the north-western coast of the Gulf of Venezuela. Samples were collected from three sites in the Venezuelan Guajira Peninsula (Castilletes, Porshoure, and Kazuzain) where patchy coral reefs and seagrass meadows are abundant. According to the substrate, two methods were performed using quantitative (1 m² quadrates), and qualitative free-diving observations. All organisms were counted and identified to the lowest possible taxonomic level; finally, diversity (Shannon diversity index), richness (number of species), and dominance in the different sampled substrates were recorded. The updated list of echinoderms of the Gulf of Venezuela reported in this research, includes 20 genera, 15 families, 10 orders, four classes, and 28 species. The richest class was Ophiuroidea, with 18 species, followed by Asteroidea, Echinoidea and Holothuroidea, with three species each. Castilletes was the sampling site with the higher number of species (18 species), followed by Porshoure (15 species), and lastly Kazuzain (12 species). Our observations indicate that the number of species and abundance were higher when found in coral reefs (21 species, 80.69% of the total collected individuals) in contrast to the species found in seagrass beds (16 species, 19.31% of the total of individuals collected). This updated list of echinoderms represents 11.54% of the total diversity of the phylum in the marine areas from the coast of Venezuela; it is suggested that this percentage is greatly influenced by the differences of habitats and substrates alongside the north-western coast in the Gulf of Venezuela.

Las asociaciones entre aves marinas y mamíferos marinos es un evento común en todos los mares y océanos del mundo. Muchos autores han denominado estas asociaciones como relaciones comensalistas, oportunistas o parasitarias, según el efecto que dicha interacción resulte sobre una o ambas especies relacionadas. Con la finalidad de describir la existencia de agrupaciones entre Sotalia guianensis y aves marinas en la porción sur del Golfo de Venezuela, desde junio 2011 a junio 2012 se realizaron observaciones en plataformas móviles de grupos de este cetáceo y aves marinas, utilizando el protocolo “group-follow” bajo la metodología de “Ad libitum sampling”. Todos los avistamientos fueron georreferenciados, realizándose anotaciones de la ocurrencia o no-asociación con aves marinas, de igual forma, se registró la especie y el número de aves presentes al momento de la interacción. Se realizaron 721 avistamientos, de los cuales en 197 eventos se registró asociación entre aves marinas y Sotalia guianensis. Las especies de aves marinas residentes que presentaron mayor frecuencia en eventos de asociación con S. guianensis fueron: Fregata magnificens (49%; n=98), Phalacrocorax brasilianus (29,5%; n=59) y Pelecanus occidentalis (22,5%; n=45); siendo Thalasseus maxima (71%; n=142) la única especie migratoria. Durante las observaciones realizadas en el período de muestreo se notó la presencia de una especie de golondrina (Riparia riparia) en un solo evento de agrupación con Sotalia guianensis. Dichas asociaciones aves-delfines, sólo fueron observadas cuando notables congregaciones de peces fueron registrados, donde el o los grupos de delfines realizaban alguna actividad con grandes movimientos de agua, lo que pudiese permitir a las aves realizar un menor gasto energético en la ubicación y la captura de la presa.

Fibropapillomatosis (FP) is affecting multiple marine turtle (MT) species worldwide. In Venezuela, the understanding about this neoplastic condition is still in early stage. Hence, this paper aims to assess the occurrence and frequency of FP in green turtles (GT) in the Gulf of Venezuela (GV). Herein, it was compiled and analyzed the reports in the database of the NGO ‘Grupo de Trabajo en Tortugas Marinas del Golfo de Venezuela’, which includes all records of stranded MT in the GV from 2000 to 2011. Between 2000 and 2006, in the GV only 2 cases of FP in MT had been reported (1.71 % of total records). Subsequently, between 2008 and 2011, encounters of FP were more frequent; resulting in a total of 7 immature GT (2.93 % of the records) documented showing large masses or skin tumors in various parts of the body. The most affected area of the MT’s body was neck and venous sinus (37.50 %), followed by the anterior flippers (18.75 %), plastron (18.75 %), posterior region (cloaca 18.75 %) and lastly, the eyes (6.25 %). All individuals presented two or more body areas with FP. Although a correlation between the presence of FP and environmental factors observed in the study area was not assessed, the turtles evaluated came from coastal waters with high levels of eutrophication, habitat degradation, and pollution. It is necessary to monitor the occurrence of this disease and the environmental factors that may negatively affect the survival of MT populations in the GV.

Los parásitos coccidiales afectan varias especies de reptiles a nivel mundial y son responsables de la muerte de cientos de ejemplares cautivos y silvestres en diferentes regiones del planeta. Entre los años 2011 y 2013, cuatro de 108 tortugas verdes (3,70 %) rescatadas por Grupo de Trabajo en Tortugas Marinas del Golfo de Venezuela, a través de la “Red de Aviso Oportuno (RAO)”, presentaron diferentes estadios evolutivos morfológicamente semejantes a Caryospora sp. en heces o tejidos. Los animales infectados fueron juveniles de tortuga verde capturados por pesquerías artesanales. Se les practicaron exámenes físicos, coprológicos y hematológicos. En tres ejemplares se observaron abundantes ooquistes de morfología compatible con Caryospora cheloniae (K001, K002, SB001). Uno de los animales presentó en capa blanca, leucocitos que contenían estructuras parecidas a esporozoitos de Caryospora sp, indicativo de coccidiosis sistémica. Dos de las tortugas se encontraron asintomáticas (K003, SB001), y dos se presentaron clínicamente enfermas con signos neurológicos como movimientos involuntarios de cabeza y aletas, espasmos musculares, movimientos natatorios circulares y depresión. Dos animales murieron (K001, K002), en ambos se encontraron diversos estadios de un organismo coccidial consistente con Caryospora sp. en intestino, además una enteritis necrótica moderada. Este constituye el primer reporte de coccidiosis en tortugas marinas en Venezuela y en el Caribe sur.