Principles of Genetics and Breeding

5.1.5 Hybridization among freshwater prawns

A cross was made between a male Macrobrachium malcolmsonii and a female M. gangeticum; these two species are considered alternative or additional candidates to M. rosenbergii for aquaculture in India. Hybrids obtained did not attain maturity within the first year of rearing but gonad maturation, breeding and spawning were observed after 14 months. F₁ and F₂ hybrids were also obtained. Earlier attempts to produce inter specific hybrids between M.rosenbergii and M. malcolmsonii suggested the presence of in complete reproductive barriers between the species. Macrobrachium species have been hybridized by natural service matings, but the development of artificial insemination techniques, and in-vitro fertilization, allowed inter species crosses where behavioral or anatomical differences prevented natural service. Hybrids that were obtained crossing female M. nipponse with the male of M. hainanense had a hatching rate of over 90 percent and a survival rate (to PL) of 20-60 percent.