Aspects of distribution, growth, and reproduction of the fluvial prawn, Macrobrachium shokitai, in a subtropical river on Iriomote Island, Japan

A female-biased sex ratio and bimodal carapace length distribution suggest that the fluvial prawn Macrobrachium shokitai on Iriomote Island, Japan, exhibits prolonged lifespan (>1 year) with distinct juvenile and adult cohorts. Recruitment occurs from August to December, while ovigerous females peak in abundance between June and August, aligning with breeding patterns typical of subtropical East Asian Macrobrachium species. Monthly sampling at seven stations along a 4.0-km river revealed stable populations above waterfalls (>270 m elevation), highlighting critical habitat preferences for this regional and vulnerable species.

Doi, W., Inoue, H., & Kohno, H. (2022). Aspects of distribution, growth, and reproduction of the fluvial prawn, Macrobrachium shokitai, in a subtropical river on Iriomote Island, Japan. Plankton and Benthos Research, 17(2), 192–200. https://doi.org/10.3800/pbr.17.192