Techniques to produce 100 percent male tilapia

A discussion is presented on endocrine sex reversal and chromosome manipulation techniques for producing 1005 male tilapia. Details are given of methods for the administration of steroids and the induction of ploidy.

Heterogeneous individual growth of Macrobrachium rosenbergii male morphotypes

In a single cohort of small freshwater prawn, Macrobrachium rosenbergii, the size range of females in the population is rather small. However, among the males, three major morphotypes are found and each has a distinct size category. The differential growth pattern in males, termed "heterogeneous individual growth" (HIG), is a major bottleneck confronting the profitability of farming this species. An attempt is made to understand the cause and impact of HIG on the culture system and methods by which HIG could be minimized in growout in order to maximize the market yield structure of the harvested population.