INDIVIDUAL GROWTH IN THE PATAGONIAN GASTROPOD BUCCINANOPS COCHLIDIUM (NASSARIIDAE): A FIELD TAGGING-RECAPTURE EXPERIMENT

AVERBUJ, ANDRES ; ESCATI-PEÑALOZA, GABRIELA ; PENCHASZADEH, PABLO E.

MALACOLOGIA

INST MALACOL

Lugar: Philadelphia; Año: 2015 vol. 59 p. 121 - 133

0076-2997

This study describes the growth of individuals in a population of Buccinanops cochlidium(Nassariidae) through the identification of the best-fitting growth model based on field tagrecapturedexperimental data. A total of 48 individuals (8.6% of total tagged snails) wererecaptured after 2 to 25 months, representing a remarkable proportion for a field experimentwith infaunal organisms. The sex ratio was not different from 1:1. Males measured between63.4 and 89.0 mm (n = 25), while females measured between 50.9 and 103.2 mm (n = 23) inshell length. The maximum annual length increment obtained was 35.74 mm, mean annuallength increment was 4.51 and 8.43 mm for females and males, respectively. Because nostatistically significant differences were found between male and female growth increments,a single growth model was fitted to the entire data set.Regarding individual growth modeling, the inverse Logistic (iLog) model adequatelydescribed the pattern in the data, but showed heteroscedasticity. A refitting of iLog usingweighted least squares, weighted inverse Logistic (iLog*), better fit the data (and agrees withbiological knowledge of B. cochlidium) than the inverse Logistic (iLog), exponential (Exp), vonBertalanffy (vB) and Gompertz (Gz) models. Estimated parameters for the iLog* model wereMaxΔL: 27.83, L50: 69.89, L95: 93.36. The results of this study are valuable for assessmentof snail fisheries in Patagonia and suggest fisheries management policies for a sustainablefuture of this potential stock prior to extensive exploitation.