Life History Characteristics of a Small Cardinalfish, Ostorhinchus rubrimacula (Percoidei: Apogonidae), from Koro, Fiji.

Abstract

We describe aspects of the life history of the small cardinalfish Ostorhinchus rubrimacula from a single, large collection taken at Koro, Fiji. We determined size at maturity and batch fecundity, examined otolith microstructure to construct a vonBertalanffy growth curve, described a length weight relationship, and performed a dietary analysis. Ostorhinchus rubrimacula is a gonochore that matures at 35 mm standard length (SL). Batch fecundity is related to body size by the equation: eggs spawned ¼ 0.0013(SL) 3:8685. Assuming each otolith ring corresponds to 1 day in age, the oldest individual in our collection lived 274 days. Growth is described by the equation: SL ¼ 40.84[l _ e_0:014ðage in days_22:45Þ]. Total body mass (mg) ¼ 4.806 _ 10_6(SL)3:5163. Ostorhinchus rubrimacula feeds primarily on harpacticoid copepods, but isopods (mostly gnathidean) and polychaetes were also important dietary components.