KR the purpose of ascertaining the migrations id growth-rate of the chank, marking experiments were begun in 1931 by the Madras Fisheries Department*. Since then about 5,000 chanks have been marked and liberated on the chank beds of Tuticorin. It was thought that there might be a migration of chanks from those beds to the Ceylon beds on the other side of the Gulf of Mannar. The experiments have shown that such migrations do not take place; but there are movements of chanks from one bed to another in the immediate vicinity. The greatest distance covered by any marked chank was nine miles.