Altered body shape as a morphometric indicator of triploidy in Indian catfishHeteropneustes fossilis(Bloch)

Triploid fish are usually detected by various cytological techniques, such as karyotyping, flow cytometry, etc. However, these methods cannot be applied on an aquaculture farm with scanty resources. In the search for an easy and rapid morphometric method various body proportion ratios were compared between diploid and triploid fish. Despite many significant differences of morphometric ratios among two ploidy groups, only the ratio between standard length and body depth (SL/BD) was found to be a precise indicator of triploidy in Indian catfish Heteropneustes fossilis under our experimental conditions. This ratio may be useful in segregating triploids from diploids of this catfish in a aquaculture farm.