Curve selection of Litopenaeus schmitti and two fish species caught by the artisanal shrimp trawl fishery in the Gulf of Paria, Sucre State, Venezuela

The extraction of penaeid shrimp in estuarine stage, is an activity that generates a continuous fishing pressure on the coastal ecosystems of the intertropical zone, for that reason this study aims to evaluate the selectivity of the artisanal trawl system with the "Chica" shrimp net. The catches were made between April and November 2008, using a trawl net with 11 m of length and 2.5 cm of mesh`s ligth and a small boat powered by two engines. In each sweep the bottom was trawled at depths below 5 m during 30 min. Net recovered the organism obtained were separated and weighed respectively. Three kg samples were transported refrigerated to the INIA laboratory in Cumana, Sucre State. Once there, they were taxonomically identified and a measured using a measuring board. Size structures of Litopenaeus schmitti were built separated by sex, Cetengraulis edentulus and Cathorops spixii , aplying the logistic equation to determine the range and size of selection respectively. The size range for female white shrimp fluctuated between 60 and 235 mm and the selection size L50% was 138.62 mm, whereas in males the size distribution was shown between 80 and 190 mm with a L50% of 131.09 mm. In the fishes, it was observed size range that oscillated between 55 and 195 mm in C. spixii and 75 and 170 mm C. edentulus, with a L50% of 105.19 mm and 124.19 mm respectively. It was observed that the gear used in this fishery is very selective as it retains a large number of bodies, most of them without having reached a commercial size. La extracción de camarones peneidos en etapa estuarina, es una actividad que genera una continua presión pesquera sobre los ecosistemas costeros de la zona intertropical, por tal motivo este estudio pretende evaluar la selectividad del sistema artesanal de arrastre con la red camaronera "Chica". Las pescas se realizaron entre abril y noviembre de 2008, utilizando una red de arrastre de 11 m de longitud y 2,5 cm de luz de malla y un bote peñero propulsado por dos motores. En cada lance se barrió el fondo a profundidades menores a 5 m durante 30 min. Recobrada la red, los organismos obtenidos se separan y pesaron, respectivamente. Muestras de 3 kg fueron trasladadas y refrigeradas en el laboratorio del INIA Cumaná, estado Sucre. Una vez allí, se identificaron taxonómicamente utilizando un ictiómetro. Luego construyeron las estructuras de tallas de Litopenaeus schmitti por sexo separado, Cathorops spixii y Cetengraulis edentulus , aplicando la ecuación lo