No abstract

Macrobrachium australe is a widespread, medium‐sized amphidromous prawn which like many other species within this genus is exploited by fisheries. As such, they are vulnerable to overexploitation as well as to environmental modifications that impact connectivity between spawning and rearing habitats. An informed understanding of reproductive biology is essential for a responsible management of stocks in species with such a complex life circle. This study reports the results of a 1‐year investigation of the reproductive biology of M. australe in the Langevin River, Reunion Island, southwest Indian Ocean. Males attained a larger size than females. The smallest ovigerous female recorded during the study was 36 mm, and females >42 mm in length were ≥50% more likely to be ovigerous. Although reproduction occurred throughout the year, there was an increase in the reproductive activity from November to May. The highest rates of ovigerous females were observed from December to March, corresponding to elevated water temperatures and, to a lesser extent, elevated river flow. Recruitment mainly occurred in the months after high female reproductive activity (January to April).