Morphometric studies on the seed of penaeid prawns of Ratnagiri coast (Maharashtra, west coast of India)

Twenty one morphometric ratios belonging to 7 size-groups were worked out i n the seed of 11 species viz Penaeus (Penaeus) monodon, P. (P.) semisulcatu s, P. (Fenneropenaeus) merguiensis, P. (F.) indicus, P. (Marsupenaeus) japo nicus, Metapenaeopsis sp., Metapenaeus dobsoni, M. monoceros, M. affinis, M . moyebi and Parapenaeopsis cornuta. The analysis of results shows that con spicuous changes occur at 10, 14, 22, 32, 40 and 50 mm sizes in almost all species. The genus Metapenaeopsis differed from the other genera by its sho rtest postorbital distance of epigastric tooth while P. (F.) merguiensis ca n be easily identified by its extremely long and slender rostrum. Splitting of the genus Penaeus into subgenera is found to be perfectly valid and the necessity of providing separate generic status to Metapenaeus dobsoni is j ustifiable.