Abstract
The life history of a caridean shrimp Palaemon inacrodactylus is discussed and its relation to the fluctuation mechanism of population size is examined. The life span is two years and the breeding season lasts from mid-April through early October. Larger II+ females begin to carry eggs earlier, followed by medium-sized I+. The breeding continues for about four months. In the latter part of the breeding season, earlier cohorts from II+ spawn just for a month. Each age group produces at least two cohorts. The relation of clutch size and clutch volume to carapace length and the maximum GSI differs depending on age, showing that the reproductive effort of 0+ is considerably larger than the older ones. The difference in reproductive ecology implies that respective age groups play a different role in the persistance of species.
