Growth, mortality and turnover rates of a small detritivorous fish

摘要

Growth, mortality and density estimates of the blenny Salarias patzneri were used to quantify turnover rates of a small-bodied detritivorous fish. Turnover rates of S. patzneri were then compared with prominent scarids and acanthurids, to assess the relative significance of small detriti-vores to secondary production on coral reefs. Instantaneous mortality, estimated from growth parameters (L_∞ = 5.10, K = 3.25, t_0 = 0.10), suggests that less than 99% of the S. patzneri population survives for more than 1 yr. Despite their small body size, high mortality rates combined with high densities give S. patzneri high annual biomass turnover rates that are similar to larger-bodied acanthurids and scarids. Dietary analysis determined that all post-settlement S. patzneri, from juveniles to the largest adults, are detritivorous. The high turnover rates and diet of S. patzneri emphasize the importance of small-bodied fish and detritus to coral reef trophodynamics.