This paper embodies a brief description of the different types (osteochondromata and osteomata) and transitional forms of tumours observed on different regions of the body of the three specimens of the cat-fish Tachysurus jella (Day), collected from the south west coast of India. The biochemical composition of the muscle and tumour tissues have been analysed and the aetiology of tumourigenesis in marine cat-fishes are discussed.

The present record is the first of such type of skin and bone tumours reported on this species which has a fairly wide distribution in the Indian Seas.