Karyological studies have been undertaken in two species
belonging to one family portunidae of decapod crustacean
collected from Chilika lagoon. The testes material of the adults
exclusively served as the source material for the chromosomal
studies. Temporary and permanent squash preparations of the
testes were stained respectively with lacto-aceto-orcein and
Heidenhain’s Iron-haematoxylin and also in air drying Giemsa
stain. These three methods were conducted but suitable
chromosome plates were obtained in air drying Giemsa
technique. Chromosome number, form and size were
determined from spermatogonial metaphase counts of these two
species. The spermatogonial chromosomes of these species are
isomorphic being rod and dot shaped and acrocentric. Minute
size and large number of the chromosomes render their counting
quite difficult. The diploid chromosome number in Scylla
serrata and Portunus pelagicus was ascertain to be 106 and 98
respectively.