Life history characteristics of a small cardinalfish, Ostorhinchus rubrimacula (Percoidei: Apogonidae), from Koro, Fiji

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 = 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 = 40.84[l - e(-0.014(age in days - 22.45))]. Total body mass (mg) = 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.