TERRITORIOS DEL PEZ STEGASTES PLANIFRONS EN FORMACIONES CORALINAS DEL PARQUE NACIONAL NATURAL TAYRONA,CARIBE COLOMBIANO:UN PANORAMA GENERAL

The pomacentrid Stegastes planifrons is one of the most conspicuous inhabitants of the coral reefs and constitutes an important agent of natural coral mortality. These fishes kill coral directly by removing coral polyps for opening up an space for its algal turfs, which are their main food. The population density, territory and algal turfs areas of Stegastes planifrons were assessed at Chengue and Gayraca bays in Tayrona Natural Park, as a contribution to understand natural processes involved in the coral reef deterioration. During August to November 1999, belt transects (20 x 2 m) were evaluated at four reef habitat types: multispecific coral assemblages dominated by (1) Colpophyllia natans (COLP) or (2) Montastraea spp. (MONT); and monospecific coral stands of (3) Acropora palmata (APAL) or (4) A. cervicornis (ACER). In total 457 fishes were censused: 21% juveniles (2.6±0.6 cm), 3% subadults or intermediates (6.6±0.5 cm) and 76% adults (12.6±0.2 cm). The highest density of S. planifrons was observed in the ACER (1.52 terr*m-2) despite this habitat is very degraded. Lower densities were found in the others habitats (~0.5 terr*m-2), but this indicates that the fish is using also alternative habitats. The algal turf size was around 0.1 m2 and significatively lowest at APAL (0.07 m2), due to the high regeneration and growth rates of A. palmata, which balance the frequent fish biting. The high densities and algal turf size of S. planifrons suggest an important role of this fish in the natural mortality and dynamics of Tayrona coral communities.