Reproductive Biology of the Silver Hatchet Chela cachius (Hamilton 1822) in a Perennial Water Body in Bangladesh.

Abstract

The reproductive biology of the silver hatchet chela, Chela cachius, was addressed in the present study. A total of 1200 specimens were caught by fine-meshed seine nets from a large perennial water body in Bangladesh Agricultural University Campus, Mymensingh. The gonadosomatic index and the histological examination suggested that the spawning seasons of C. cachius were from February to May and from July to September. Based on histological examination, nine stages of oocyte development were determined; namely, early perinucleolus, late perinucleolus, yolk vesicle, primary yolk, secondary yolk, tertiary yolk, migratory nucleus, premature and mature stage. The absence of postovulatory follicles and hydrated eggs and the presence of two modes of eggs in the mature ovaries indicated that C. cachius was a single spawner, and its spawning frequency or strategy was a synchronous type. The average fecundity was 1708±838.86 having a standard length of 49±2.89 mm in the first season (February to May) and 1997.33±889.92, whereas the standard length was 46.66±1.53 mm in the second season (from July to September). The findings of the present study might be helpful for induced breeding of the species for commercial purposes as well as for management of the natural population (banning/restriction of fishing during spawning season) of C. cachius.