Statistique de pêche et étude biométrique de quelques espèces d’Échinoderme des fonds chalutables de la côte de Mostaganem.

Abstract

The present study is part of the fishery resource assessment of the Algerian coast and it contributes to the knowledge and the valuation of some species of Echinoderms fished as by-catches at the level of some stations of the trawlable bottom of the coast of Mostaganem.. Regarding bycatch, this work has enabled us to identify 6 species of Echinoderms (5 Asterids and 1 holothurid of the Stichopodidae family). Measurements were taken on individuals of each type of species. For starfish, we adopted the biometric measures proposed by (Gianguzza et al., 2015). The results of the study of metric parameters showed that starfish individuals are characterized by a negative allometry (length-weight relationship), while for linear evolution the nature of growth changes with the biometric measurements considered. Similarly, we found that the new biometric parameters [Arm Height: HB & Arm Width: LARB] of the (Gianguzza et al., 2015) protocol show much greater correlations with the weights of the studied starfish. This is a promising result for the use of this protocol in other studies and it help to standardize the measurements of different body parts of species of the Asteroid class. In addition, this study allowed us to report for the first time the presence of a starfish which has never been recorded in previous studies on Asteroid species in the western basin of the Algerian coast. These are two individuals of Chaetaster longipes (Retzius, 1805). In addition, inspection of the stomach contents of Astropecten aranciacus allowed us to confirm the voracity of this species. We have found that ingestion is intraoral and it appears that this species has the ability to select its prey based on the sizes of their tests.