Population dynamics of the soldier crab Mictyris guinotae (Brachyura: Mictyridae) in Amparu Tidal Lagoon on Ishigaki Island, Japan

The results showed that (a) the peak of incubation was from mid-January to mid-February, and the season of juvenile settlement was April to early June, which means that the duration of larval life in the ocean was about 2 months; (b) juveniles were distributed widely in the lagoon, and adults clustered to the west and south of the lagoon where the bed sediment was relatively fine with high ignition loss; (c) the survival rates of adults and juveniles in 1 year were 0.73 and 0.17, respectively, and the mean longevity of adults was about 3.7 years; (d) reproduction efficiency from eggs to juveniles was about 0.0040, which is much smaller than the survival rate of juveniles as well as adults, which means that the propagation of M. guinotae is mainly controlled by the condition that the larvae experience in the ocean.