Early life history of the argentine sea bass (Acanthistius patachonicus) (Pisces: Serranidae)

Abstract

The Argentine sea bass (Acanthistius patachonicus) is one of the most conspicuous and abundant species in the rocky-reef fish assemblage of Northern Patagonia, which sustains important recreational and commercial activities, such as scuba diving, hook-and-line fishing, and spear fishing. We describe the morphological features of eggs, larvae, and posttransition juveniles of A. pa\tachonicus and summarize abundance and distribution data for larvae collected on the Argentine shelf (between ~40°S and 44°S). Eggs and yolk-sac larvae came from an in vitro fertilization experiment. Larger larvae were distinguished by relevant morphological features, including the development of the opercular complex and head spination, meristics, and pigmentation pattern. The early stages of A. patachonicus are similar to those of the koester (A. sebastoides) and of the western wirrah (A. serratus), the other 2 species of Acanthistius whose larval development has been described. The body and head in A. patachonicus were moderate in size, but its preanal length was long. The particular head spination pattern of larvae of A. patachonicus, namely a few conspicuous smooth spines (mainly on the preopercle and opercle), and 2 posttemporal spines, was useful for differentiating this species from others and, therefore, made it possible to describe the whole developmental series and to link the early stage morphological features to those of adults.