Reproduction and spawning habitat of white trevally, Pseudocaranx dentex, in the Azores, central north Atlantic

Reproductive biology and habitat preferences of the white trevally, Pseudocaranx dentex (Carangidae), were studied in the Azores islands, central north Atlantic, to determine the spatial and seasonal dynamics of habitat use of immature and mature fish. The sex ratio was close to 1:1 and fish matured...

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Bibliographic Details
Published in:Scientia Marina
Main Authors: Pedro Afonso, Jorge Fontes, Telmo Morato, Kim N. Holland, Ricardo S. Santos
Format: Article in Journal/Newspaper
Language:English
Published: Consejo Superior de Investigaciones Científicas 2008
Subjects:
Online Access:https://doi.org/10.3989/scimar.2008.72n2373
https://doaj.org/article/c4f665289bf248ffaf725e119b8a8118
Description
Summary:Reproductive biology and habitat preferences of the white trevally, Pseudocaranx dentex (Carangidae), were studied in the Azores islands, central north Atlantic, to determine the spatial and seasonal dynamics of habitat use of immature and mature fish. The sex ratio was close to 1:1 and fish matured at about 30 cm fork length. There were no differences in the maturation or length-weight relationships between sexes. The spawning season lasts from June to September. Underwater visual censuses showed that schools of mature individuals preferentially aggregate around the summits of offshore reefs during the spawning season. In contrast, schools of smaller, immature fish use inshore habitats all year round. Our data support the hypothesis that offshore reefs are a preferential spawning habitat of larger white trevally, and most possibly for a number of visitor pelagic predators as well. Inverse relationships between exploitation levels, abundance and size composition at the two different islands suggest that the summer fishery targeting trevally schools around offshore reefs has negatively impacted the population. These findings bring additional ecological and management relevance to offshore reefs.