Relação peso comprimento das principais espécies capturadas na pesca de arrasto de camarão e de armadilha na praia de São Cristovão, Areia Branca – RN

Abstract

When studying a population, the length-weight relationship is one of the most important parameters, since it helps to know the life cycle and shows a better way of estimating the length through the weight of the fish, and vice versa. In addition to estimating growth, it functions as an indicator of fat accumulation and gonadal development. The objective of this work was to estimate the length - weight ratio of the species caught in shrimp trawling and in fishing traps for reef fish in the São Cristóvão beach in the city of Areia Branca, Rio Grande do Norte, Brazil. The samplings were carried out monthly, from February 2010 to January 2011. In each sampling, three trawls were carried out with a time of 10 minutes each and the species that were in the traps were collected. Twelve species were analyzed: Anchoa spinifer (n = 129), Cathrops spixii (n = 1267), Chaetodipiterus faber (n = 72), Conodon nobilis (n = 185), Haemulon parra (n = 85), Haemulon stendachineri (N = 267), Isopisthus parvipinnis (n = 93), Larimus breviceps (n = 679), Lutjanus synadris (n = 206), Menticirrhus americanus (n = 267), Pomadasys corviniformis. The data of length (cm) and weight (g) of each of these species were obtained and through the RStudio program, parameters a and b were estimated from the regression analysis according to the equation: ln (W) = ln (a) + bln (L). The relationships were: A. spinifer (ln (W) = ln (4,881) + (3,013) ln (L)), C. spixii (ln (W) = ln (3.824) + (2.689) ), C. faber (ln (W) = ln (3.076) + (2.873) ln (L)), C. nobilis (ln (W) = ln (4.585) + (3.116) (W) = ln (4.016) + (2.951) ln (L)), H. stendachineri (ln (W) = ln (4.028) + (2.965) ln (L)), I. parvipinnis (ln (W) = ln (4,714) + (3,009) ln (L)), L. breviceps (ln (W) = ln (4,368) + (2,952) ln (L) Ln (3,994) + (2,926) ln (L)), M. americanus (ln (W) = ln (5,253) + (3,231) ln (L)), P. corviniformis + (3.116) ln (L)) and S. setapinnis (ln (W) = ln (3,499) + (2,655) ln (L)). Most species differ from data observed in the literature and this occurs because the study region is a sandy beach while studies are more common in estuary areas and in beach regions farthest from the coast. The sandy beaches are characterized by having a large number of young and migratory species, differing from other places. It can be said that many differences may be associated to the different environmental and biological conditions that the population is subjected, having, most of the time, a differentiated growth from place to place.