STUDIES ON SOME ASPECTS OF BIOLOGY AND TRANSPLANTATION OF THE CLAM MERETRIX CASTA (CHEMNITZ) IN THE BHEEMUNIPATNAM BACKWATERS

Studies on the growth of Meretrix casta (Chemintz) showed that the clams in the natural bed grew at the rate of 3.6-3.9 mm per month while the speciemens kept in the cages showed growth rates of 0.9 mm and 0.77 mm per month respectively for on bottom and off bottom culture. The equation for length weight 3.2261. relation was found to be W — 0.0002221 L The spawning period of M. casta was found to be between April-May. Dispersal of clam seed in virgin areas did not yield fruitful results as there was heavy mortality due to floods. INTRODCTION A BED of Meretrix casta was located in the backwaters of Bheemunipatnam near Nagamayyapalam, situated about 32 kilometers north of Vishakhapatna m during a survey of the area for finding out suitable sites for marine fish farming. Some aspects of the biology of the clam have been studied. During 1977 and 1978 attempts were made to transplant the seed of clams and the results of the experi­ ments are given in this paper.