Lobster fishing in Ceylon

The presence of spiny lobsters in the reefs lying off the coasts of Ceylon is known to local fishermen and skin divers. However, a well-established fishery for these lobsters does not exist as fishermen engaged occasionally in this activity catch only a few lobsters during the course of a day's fishing. Considering the present state of development of lobster fishing in Ceylon, it is not possible to state whether lobsters are found in sufficient numbers in the seas off Ceylon. This knowledge is very important before the introduction of new methods of fishing can be made. Experiments were therefore conducted to determine the most efficient type of trap that could be used to appraise the resources present in the coral reefs and other rocky areas. Designs of traps, similar to those used in Scotland, England, Wales and Canada, were made locally. These were tested for efficiency in areas known to be inhabited by spiny lobsters.

Food preference and intake pattern of Penaeus monodon (Fab.) in semi-intensive culture system

P. monodon juveniles prefer natural food than artificial feed in their initial stage of rearing. However, the percentage preference towards artificial feed increases as the days of culture/average body weight increases. Consumption of artificial feed was high during evening meal (1700h) and low during night meal (2200h). The index of intestine fullness was high (8.4±0.7) during initial stage of rearing, compared to that of final stage of rearing (4.9±0.4), probably due to low nutritional value of intake material and low water depth at initial stage. At all stage of rearing omnivorous feeding habit was established and no evidence of diet periodicity in feeding activity was observed.