Abstract The nesting characteristics (number of nests and eggs, time of year, nesting initiation, and nesting length) of leatherback (Dermochelys coriacea) and hawksbill (Eretmochelys imbricata) sea turtles of the southern Caribbean Sea (specifically in the Gulf of Paria in Venezuela), were examined in association with weekly precipitation averages and number of rainy days per week during the period between 2009 and 2018. We hypothesized about the influence of rainfall intensity and patterns as the main abiotic factor for sea turtle nesting. On average, leatherbacks preferred nesting during the drier season of each year (March, April, and May), while hawksbills nested during the rainy season (June to September). For both species, we found few significant correlations between the number of nests or clutch size (number of eggs per nest) and weekly averages of seasonal precipitation rates in the region. Average hawksbill clutch sizes were not correlated with average precipitation rates but were positively correlated with the number of rainy days per week (r=0.66, P≤0.05). Average hawksbill clutch sizes decreased each year on average (-3.3 eggs/year, r=-0.88, P≤0.001), which coincided with a negative long-term trend in the number of rainy days (-0.11 rainy days/week, r=-0.69, P≤0.05). During the study period, nesting activities for both leatherback and hawksbills started progressively later (0.9 and 0.6 weeks/year, respectively p≤0.05) and were shorter (-0.9 and -0.8 weeks /year, P≤0.1 and P≤0.05, respectively).

Abstract 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.

RESUMEN 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.

ABSTRACT Coccidian parasites affect several reptilian species worldwide and they are responsible of the demise of hundreds of specimens either in the wilderness or in captivity among several localities throughout the world. Between 2011 and 2013, four out of 108 individuals (3.70 %), were rescued by the Grupo de Trabajo en Tortugas Marinas del Golfo de Venezuela (GTTM-GV) through its protocol 'Red de Aviso Oportuno' (RAO), shown symptoms and signs of a possible disease morphologically resembling to Caryospora sp. in intestines and other tissues. Physical, coprological and hematological examinations were carried out to juvenile specimens of Green Turtles captured by artisanal fishing gear. We found abundant oocysts with morphologies compatible with Caryospora cheloniae in three individuals (K002, K003, and SB001). One of the sampled individuals exhibited leukocytes containing structures similar to sporozoites of Caryospora sp., indicating a systemic coccidiosis. Two of the evaluated turtles (K003, SB001) were asymptomatic, and the other two (K001, K002) were clinically ill with neurological signs, such as involuntary movements of the head and flippers, muscle spasms, circular swimming movements and depression. Two of the turtles studied died, in both were found several parasitic stages of a coccidial structure in their intestines, and severe necrotic enteritis. This is the first report of coccidial disease in marine turtles in Venezuela and the southern Caribbean.

ABSTRACT. The longnose stingray (Dasyatis guttata) is a target species in the artisanal fisheries of the southern Gulf of Venezuela. Despite its economic importance, nowadays, studies about its status are lacking. During six continuous months (18 working days in total), we followed the artisanal fishery activities from Zapara Island, and evaluated morphometric characteristics, sex ratio, and the capture per unit effort (CPUE/ind/1000 hooks) of D. guttata. Biological sampling included: disc widths (AD), body mass total (PT), and sex. Using statistical analysis we assessed: a) the length-weight relationships by sex, b) monthly body condition, using the Fulton Index (K), and c) the CPUE. We evaluated 210 individuals of D. guttata. The mean values of our results were: AD = 64.14 ± 13.18cm (range 32-95 cm); PT = 8.36 ± 4.87 kg (range 0.8024.50 kg). The sexual proportion was (2.26♀: 1♂) (χ2 = 31.71; P < 0,05); hence we presume a spatial segregation occurred between females and males in the studied area. Length-weight relationship was statistically significant (P < 0.0001), and also varied according to the sex ♀: PT(kg) = [(0.00027)×(AD(cm)246)]; ♂: PT(kg) = [(0.00035)x(AD(cm)2.34)]. The K value showed differences between sexes during November and December. We obtained a CPUE of 4.88 individuals/1000 hooks. We compared our findings with previous research carried out in the southern Caribbean. Further research about this species in the area is recommended.

RESUMEN. La raya látigo Dasyatis guttata es una especie objetivo en la pesca artesanal del sur del Golfo de Venezuela. A pesar de su importancia económica, actualmente pocas evaluaciones se han efectuado para conocer su estado. Con el seguimiento de las actividades pesqueras de la flota artesanal de Isla Zapara, se evaluaron las características morfométricas, composición de sexos, captura por unidad de esfuerzo (CPUE, ind/1000 anzuelos), de D. guttata, durante seis meses continuos de muestreo (18 días de pesca). Los muestreos biológicos mensuales incluyeron el ancho de disco (AD), peso total (PT), y sexo. Se evaluó a) la relación talla-peso para cada sexo, b) el factor de condición mediante el índice de Fulton (K) mensual, y c) la CPUE. Se consideraron 210 ejemplares de la especie. Se obtuvo un promedio de AD = 64,14 ± 13,18 cm; (rango 32-95 cm), y de PT = 8,36 ± 4,87 kg (rango 0,80-24,50 kg) y proporción sexual de (2,26♀: 1♂) (χ2 = 31,71; P < 0,05), por lo que se presume una segregación espacial de hembras y machos en la zona. La relación talla-peso fue significativa (P < 0,0001), y diferentes para cada sexo ♀: PT(kg) = [(0,00027)x(AD(cm)2,46)]; ♂: PT(kg) = [(0,00035)×(AD(cm)2,34)]. El valor K mostró divergencia entre sexos en noviembre y diciembre. La CPUE se estimó en 4,88 ind/1000 anzuelos. Se compararon estos resultados con investigaciones previas en la región sur del Caribe y se recomiendan mayores estudios de la especie en esta zona.

Las pesquerías artesanales del Sistema de Maracaibo juegan un papel importante en el uso de los recursos acuáticos por parte de las comunidades costeras de la región. Sin embargo, estas carecen de estudios que evalúen su aprovechamiento y posible sostenibilidad. Por tal motivo, se llevó a cabo un estudio sobre la pesquería de la almeja Rangia cuneata; el cual consistió en la evaluación del índice de condición (IC), la composición de tallas, morfotípos y la relación talla/peso en los bancos adyacentes al asentamiento pesquero del Curarire. Los muestreos se realizaron mensualmente durante 7 meses, empleando la técnica usada por los pescadores, esta consistió en colectar las almejas con la mano desnuda directamente del bentos. Se cuantificaron un total de 1.120 organismos, con un rango de tallas de 10 a 55 mm. El análisis de la distribución de tallas sugieren una constante renovación de la población, coincidiendo con el ciclo reproductivo continuo para R. cuneata en ambientes tropicales. El intervalo 30-35 mm dominó la distribución de tallas con el mayor IC. El mayor rendimiento (talla/peso) se observó para el morfotipo de almejas de concha fina, llegando su rendimiento hasta 15,22% en el mes de diciembre. Se evidenció una asociación estadísticamente significativa entre la talla y el peso, con un ajuste del 69,79% para el modelo potencial. La explotación pesquera y las condiciones ambientales han condicionado la talla media de la población, mientras que el índice de condición se vio afectado por los morfotipos.

ABSTRACT The artisanal fisheries in Maracaibo System play an important role in the use of aquatic resources by coastal communities in the region. However, they lack of studies evaluating its exploitation and potential sustainability. We conducted a study on the clam Rangia cuneata fishery; which consisted of the evaluation of condition index (IC), size composition, morph type and size/weight from the banks adjacent to the fi shing settlement of Curarire. Samples were taken monthly along 7 months, using a technique similar to the used by zone fishermen, which is to collect the clams by his bare hand directly from the sediment. A total of 1,120 organisms, with a size range of 10 to 55mm. The results suggest a constant renewal of the population, coinciding with the continuous reproductive cycle for R. cuneata in tropical environments. The interval 30-35mm dominated the distribution of sizes, with the largest IC. The highest yield (height / weight) was observed for the morphotype of thin shelled clams, reaching its yield up to 15.22% in December. It was evidenced a statistically signifi cant association between in the size and weight, with an adjustment of 69.79% for the potential model. The fi sheries exploitation and environmental conditions has conditioned the average size of the population, while the condition index was affected by the morphotypes.

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.

Associations between seabirds and marine mammals are a common event in all seas and oceans of the world. Several authors have called these associations as commensal, opportunistic or parasitic relationships, depending on the result of such interaction effect on one or two related species. In order to describe the presence of associations among Sotalia guianensis and sea birds in the southern region of the Gulf of Venezuela, from June 2011 to June 2012, observations of groups of this cetacean and seabirds were made on mobile platforms, using the "group follow" protocol following an "Ad libitum sampling". All sightings were geo-referenced and annotations about the occurrence or non-association with seabirds, species and number of birds present at the association were made. During the sampling period 721 sightings were recorded, of which 197 events of aggregation between seabirds and S. guianensis were registered. The resident seabird species most frequently presented at each event associated with S. guianensis were: Fregata magnificens (49%; n=98), Phalacrocorax brasilianus (29.5%; n=59) and Pelecanus occidentalis (22.5%; n=45); being Thalasseus maxima (71%; n=142) the only migratory species. During all sampling sightings was observed only one interaction between a swallow species (Riparia riparia) and Sotalia guianensis. These bird-dolphin associations were only observed when a notable congregation of fish was registered and a dolphin or a group of dolphins were performing any activity with large movements of water that allowed birds to find and locate their preys with low energy cost.