Variaciones en la condición nutricional de langostas Panulirus argus (Decapoda: Palinuridae) en la región este del Golfo de Batabanó, Cuba
Alexander Lopeztegui Castillo, Norberto Capetillo Piñar & Abel Betanzos Vega
ABSTRACT
Variations of the nutritional condition of lobsters Panulirus argus (Decapoda: Palinuridae) in Eastern region of the Gulf of Batabanó, Cuba. Nutritional condition can affect survival and growth rate of crustaceans, and this is mostly affected by habitat conditions. This study describes the space-temporary nutritional changes in this commercially important species. With this aim, the variations in the nutritional condition (K) of lobsters from four zones (1, 2, 4 and 5) in the Gulf of Batabanó, Cuba, were determined. For this, the weight/length ratio (K=Pt/Lt) was calculated using animals captured in 1981 and 2010. The nutritional condition between areas and sexes, and years and sexes, was contrasted by a bifactorial ANOVA, and the overall length and weight of lobsters were compared using a t-Test for independent samples and unifactorial ANOVA. It was found that the nutritional condition was significantly greater in males than in females. In addition, significant variations between zones were detected for both years. Nutritional condition of lobsters from Zone five was the highest for 1981, while it was Zone two for 2010. Lobsters nutritional state showed significant variations between years, being greater in 1981 (2.34±0.84g/mm) than in 2010 (1.96±0.49g/mm). The inter-zones variations as well as the inter-annual ones seem to be related to the reported variations of the bottom type and the vegetation cover. Seasonal variations in the abundance and distribution of benthic organisms, that constitute food for lobsters, could also be influencing. The differences between sexes, however, were assumed as a consequence of the methodology used and the sexual dimorphism of the species. Due to other K estimation methods, that do not include morphometric measurements, these differences were not detected. We suggested that the P. argus nutritional condition is a good estimator of the habitat condition. Besides, according to the applied K estimation methodology, it was found that different groups of lobsters that have resemblant nutritional condition, did not necessarily observe similarities in the overall mean length or weight, so they could exist under different habitat conditions.
RESUMEN
En Cuba, la región del Golfo de Batabanó es la más importante zona de pesca de langosta debido a que de ella se extrae anualmente alrededor del 70% de la captura nacional. Con el objetivo de determinar variaciones espacio-temporales en la condición nutricional (K) de langostas Panulirus argus del Golfo de Batabanó, Cuba, se calculó dicha condición mediante una relación pesolargo (K=Pt/Lt), para lo que se utilizaron ejemplares de cuatro zonas (uno, dos, cuatro y cinco) del este del golfo, capturados en los años 1981 y 2010. Se encontró que en todos los casos analizados la condición nutricional fue significativamente mayor en machos que en hembras. Se detectaron variaciones significativas entre zonas en 1981 y 2010. También entre años el estado nutricional de las langostas presenta variaciones significativas, de manera que en 1981 (2.34±0.84g/mm) fue mayor que en 2010 (1.96±0.49g/mm). Tanto las variaciones interzonales como las interanuales parecen estar relacionadas con variaciones reportadas en el tipo de fondo y la cobertura vegetal. Variaciones estacionales en la abundancia y distribución de organismos bentónicos que constituyen alimento para las langostas también podrían estar influyendo. Las diferencias entre sexos en cambio, se suponen consecuencia de la metodología utilizada y del dimorfismo sexual característico de esta especie, por cuanto otros métodos de estimación de K que no involucran mediciones morfométricas, no detectan estas diferencias.