Individual male Macrobrachium rosenbergii de Man have different growth rate

the phenomenon is known as heterogeneous individual growth (HIG). Fast-growing individuals or "jumpers"grow 15-times faster than slowgrowing individuals or"laggards". Past studies suggested that environmental factors play role in HIG. Genetic factor is believed not to be implicated in this phenomenon, although a direct positive evidence has not been demonstrated. In this study DNA of jumpers and laggards were digested by either PstI or BamHI restriction enzyme, hybridized with M13 probe and detected by nonradioactive method. The result revealed that both jumper and laggard DNAs have identical patterns of DNA fingerprints, suggesting that HIG may not be due to a difference in genetic materials in the two groups. The enzymes and probe were also used to study DNA fingerprints of two brackish-water species, Penaeus monodon and Penaeus Yannamei, which revealed a smear pattern suggesting different genetic traits from that Macrobrachium rosenbergii of Macrobrachium rosenbergii.