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

378-388Twenty one morphometric ratios belonging to 7 size-groups were worked out in the seed of 11 species viz Penaeus (Penaeus) monodon, P. (P.) semisulcatus, P. (Fenneropenaeus) merguiensis, P. (F.) indicus, P. (Marsupenaeus) japonicus, Metapenaeopsis sp., Metapenaeus dobsoni, M. monoceros, M. affinis, M. moyebi and Parapenaeopsis cornuta. The analysis of results shows that conspicuous 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 shortest postorbital distance of epigastric tooth while P. (F.) merguiensis can 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 justifiable