Habitat overlap of Paralabrax humeralis (Cuvier & Valenciennes, 1828), Hemilutjanus macrophthalmos (Tschudi, 1845), and Acanthistiuspictus (Tschudi, 1845) (Pisces; Serranidae) in the rocky subtidal south of Iquique, Chile

Abstract

A simple SCUBA diving survey was used to study the habitat use and coexistence of three spe- cies in the family Serranidae with sympatric distribution patterns along the rocky subtidal south of Iquique. Depth and microhabitat were recorded for each sampled individual. Samples were taken at 15 different beaches through SCUBA diving in the deepest areas of the first rocky fringe, herein referred to as the transi- tion zone. The data were analyzed according to depth and frequency of use (microhabitat, habitat) for each species and considering three size classes. Dendograms were created to interpret the similarities in the use of beaches, microhabitat, and habitat. The results showed the species to be independent in their use of the micro- habitat and habitat. The most abundant species was the roving Paralabrax humeralis whose habitat was mostly associated with Lessonia trabeculata. Hemiluthjanus macrophthalmos and Acanthistius pictus are cav- ity specialists, although their microhabitat use differed according to the size of the cavity: H. macrophthalmos occupied larger caves (> 0.5 m) and A. pictus mostly smaller cavities (< 0.5 m). The lack of juvenile A. pictus individuals seems to indicate the use of an alternative ecosystem. The distribution patterns of these Serranids varied throughout the study area, indicating a dependence on the geomorphology of the substrate and the pres- ence of the structural species L. trabeculata.