Development and Occurrence of Early Stages of Dules auriga in the Northern Patagonian Gulfs of Argentina

The family Serranidae comprises a large group of marine fishes distributed worldwide. The identification of early stages of serranids at the species level is difficult due to a high family diversity and to overlapping morphological and meristic features. In this study, we describe morphological and meristic features of early stages of Dules auriga and summarize density and distribution data for larvae collected in the San José Gulf, Península Valdés, Argentina. Larvae were distinguished by relevant morphological features that include opercular complex development, meristic features, pigmentation pattern, the sequence of appearance of fin elements, and the structure of the caudal region, typical of serranids. The elongated third dorsal spine, characteristic of adult D. auriga, was not observed. Two preflexion larvae were identified using COI barcoding to confirm the species identity. Morphological features described here helped to discriminate D. auriga from other serranids occurring in the area and enabled reconstruction of the entire developmental series and linkage between early stages and adults.