Population Characteristics of the Mud Crab (Scylla olivacea) in the Mangrove Ecosystem of Ambon Bay, Maluku, Indonesia

This study examines the population dynamics of the mud crab ( Scylla olivacea ) in the mangrove ecosystem of Ambon Bay, Indonesia, over a full annual cycle, highlighting both spatial and temporal patterns. Sampling was conducted purposively across four zones (seaward, frontal, central, and rear) in Passo, Waiheru, and Tawiri. Parameters analyzed included density, sex ratio, size structure, growth patterns, condition factors, and reproductive stages. Results show declining population density, with the highest densities in rear and frontal zones characterized by dense mangrove vegetation and fine substrates. The sex ratio was male-biased, while female individuals were predominantly small (< 13.4 cm), suggesting potential overexploitation. Growth patterns exhibited spatial variability, with positive allometry in Passo and Waiheru but negative allometry in Tawiri. Reproductive activity occurred year-round, peaking in February and August, with mature females concentrated in zones with high salinity and temperature. This study is novel integrating spatial and temporal analyses over an annual cycle, providing a comprehensive understanding of S. olivacea population ecology. The findings emphasize the need for sustainable management and habitat conservation to ensure the species’ long-term viability and its ecological and economic roles.