Field validation of an all-female monosex biotechnology for the freshwater prawn Macrobrachium rosenbergii

A major drawback in prawn aquaculture lies in its bimodal growth and wide size distribution, limiting stocking densities and the ability to reach industrial-sized yields. Nonetheless, this limitation may be overcome through the culture of monosex populations. The recent establishment of a non-GMO WW-based biotechnology for all-female monosex production—achieved through manipulation of the androgenic gland hormone-sexual switch (IAG-switch) using parental cell transfer—enabled, for the first time, the mass production of all-female specimens that facilitated the present study. Here, we report the first large-scale field validation of the all-female Macrobrachium rosenbergii biotechnology, conducted over three consecutive years and investigating a range of high stocking densities from 10 to 20/m² in combination with different nursery practices. All-female populations resulted in higher yields at harvest (up to 4474 kg·ha⁻¹) compared to previous prawn culture records producing medium-sized specimens with excellent size uniformity (3.8 % to 12.2 % CV) and an average weight of 31.5–54.8 g. Female reproductive state at harvest included high rate (above 77 %) of actively reproductive females (no fertilization due to the lack of males). If females do not invest energy in vitellogenesis as suggested by the high rate of reproductive activity, potential higher growth could be achieved as well as potential shortening of the grow-out period. The feasibility and advantages of all-female biotechnology for high yields of prawns comprised of uniform medium-sized specimens are demonstrated. Insights into the advantages for processing of a uniform sized product were generated, which could significantly impact the global prawn industry.