Nursery habitat and diet of juvenile centropomus species in puerto rico estuaries

Abstract

The distribution of the early stages of five species of Centropomus was studied in Puerto Rico and varied among the est narine areas sampled. Based on the collection of 4,710 juvenile snook, the study showed that the most abundant species (standard length < 50 mm) collected in river systems was C. parallelus (81%); in contrast, C. undecimalis (62%) and C. ensiferus (35%) were more abundant in lagoon systems. Colonization peaks of the three most abundant species showed broad overlapping: from June to Nov. for C. undecimalis, from July to Dec. for C. ensiferus, and from April to Nov. for C. parallelus. Preferred nursery habitats were turbid, calm waters in the vicinity of shelter (mangrove roots, grass, or water hyacinths). The physical parameter range of juvenile snook habitat was relatively broad: salinity from 0 to 30 ppt temperature from 24 to 35 C, and anoxic to welloxygenated water. Condition factors of two size classes of snook (less than 100 mm and between 100 and 300 mm in standard length) showed no significant differences between river and lagoon systems or between seasons. Food habits were significantly different between species during the early stages (standard length < 100 nun), but this difference was resolved when river and lagoon samples were studied separately. In the river system, C. undecimalis and C. ensiferus preyed primarily upon shrimp, whereas in the lagoon they fed mainly on fish. © 1997 by the Marine Environmental Sciences Consortium of Alabama.