CULTURE OF Macrobrachium acanthurus AND M. carcinus WITH NOTES ON THE SELECTIVE BREEDING AND HYBRIDIZATION OF THESE SHRIMPS1

Brood stock of Macrobrachium acanthurus and M. carcinus was caught in Spring, 1973 by dip netting at night in local canals. Larvae secured from ovigerous females were raised primarily in 946‐liter tanks, and were fed Artemia nauplii, Tetramin, and ground tuna in initial experiments. In later rearing experiments, Artemia nauplii alone were used and were added to a rearing tank at the rate of the Artemia hatched from 25 cc of cysts per day. Two weeks after attaining the postlarval stage, the young shrimp were placed in 1/75th to 1/100th ha ponds. Data for male M. acanthurus show that they grow to a mean size of 10.0 cm in 4 months and 12.1 cm in 6 months. Females grow considerably more slowly, at least after achieving sexual maturity, and outnumber the males by about three to one. Insufficient postlarvae of M. carcinus were obtained from larval rearings to allow meaningful pond culture experiments. Attempts at hybridization of the two species were unsuccessful. Seminal fluid was removed from male M. carcinus by means of a hypodermic syringe with a blunt needle, but attempts to artificially inseminate females also failed.