Identificación de stocks pesqueros de la corvina de río (Plagioscion ternetzi) de los ríos Paraguay y Paraná, mediante el análisis morfométrico de sus otolitos

AVIGLIANO, ESTEBAN; COMTE, GUY; ROSSO, JUAN JOSÉ; MABRAGAÑA, EZEQUIEL; DELLA ROSA, PAOLA; SÁNCHEZ, SEBASTIÁN; VOLPEDO, ALEJANDRA; DEL ROSSO, FRANCO; SCHENONE, NAHUEL FEDERICO

LATIN AMERICAN JOURNAL OF AQUATIC RESEARCH

UNIV CATOLICA DE VALPARAISO

Lugar: Valparaíso; Año: 2015 vol. 43 p. 718 - 725

0718-560X

The identification of fish stocks in basic requirement for fishing management. The objective of this research was to describe for the first time otoliths river crocker (Plagioscion ternetzi) and to evaluate the existence of different fish stocks in the Paraguay River lower basin and the middle Paraná River (northeast Argentinean region and southeast Paraguayan region). For this purpose, five morphometric indexes applied on sagitta otolith (rectangularity, circularity AO/SO, SS/SO and PS/PO) were compared between the study sites. The sagittae otoliths are semicircular and with smooth edges. Sulcus acusticusis is heterosulcoid and curved, with an ostium open widely in the anterior margin of the otolith. Significant differences were observed for circularity, rectangularity, SS/SO and PS/PO (t-test, P < 0.05). The T2 Hotteling multiparametric analysis showed significant differences between the study sites (P < 0.006), while the canonical discriminant showed a high classification percentage of the individuals (>69%). The results indicates that the stocks populations would be partially separated, with a considerable flow of individuals between these rivers.