ARTIFICIAL PROPAGATION OF MILKFISH

PROJECT FOCUSES UPON ARTIFICIAL PROPAGATION OF MILKFISH, AND STRESSES FISH HUSBANDRY, BREEDING RESEARCH, AND DEVELOPMENT OF A SYSTEM FOR THE DISTRIBUTION OF JUVENILE FISH TO AQUACULTURAL FACILITIES DURING FIRST TWO YEARS, SPAWNING FISH WILL BE CAPTURED AT SEA IN THEIR NATURAL SPAWNING GROUNDS; IMMATURE FISH WILL BE CAPTURED IN FRESH AND BRACKISH WATER AND ALLOWED TO MATURE IN SEAWATER IN CAPTIVITY; MIGRATORY SPAWNING FISH WILL BE CAPTURED AS THEY MOVE OUT OF FRESHWATER AND RELOCATED IN SALTWATER. THIS LARGE POPULATION WILL FORM THE BASIS OF HUSBANDRY RESEARCH TO DETERMINE FOOD REQUIREMENTS, WATER CONDITIONS, AND OPTIMAL POPULATION DENSITY FOR HOLDING ADULTS. THESE FISH ALSO FORM THE GENE POOL FOR BREEDING RESEARCH, AND EACH WILL BE MARKED AND MONITORED TO DETERMINE ANNUAL FERTILITY AND QUALITY OF GAMETES. IN AN ATTEMPT TO INDUCE SPAWNING IN CAPTIVITY, SALINITY, TEMPERATURE, AND PHOTOPERIOD WILL BE REGULATED TO STIMULATE (THROUGH CHANGES IN PITUITARY PRODUCED HORMONES) SEASONAL MATURITY OF GONADS. ALTHOUGH HORMONE TREATMENT IS ANTICIPATED AS BEING ESSENTIAL TO COMPLETE SPAWNING PROCESS, EFFORTS WILL ALSO BE MADE TO CREATE OPTIMUN CONDITIONS FOR NON-HORMONE-INDUCED SPAWNING. SPECIAL ATTENTION WILL BE GIVEN REFINEMENT OF PROCEDURES (DOSAGE, TIMING, ETC) FOR USE OF SALMON PITUITARY GONADOTROPIN AS HORMONAL AGENT. UPON SUCCESSFUL INCUBATION OF FERTILIZED EGGS, RESEARCH WILL FOCUS ON INCREASING SURVIVAL OF LARVAE THROUGH JUVENILE STAGE, INCREASING HARDINESS OF JUVENILES, AND DEVELOPING TECHNIQUES FOR COLLECTION AND TRANSPORTATION OF JUVENILES. CONTRACT AMENDMENT 2/27/76 ADDS STUDY OF BEHAVIORAL AND ORGANIC PATHOLOGIES OF MILKFISH IN CAPTIVITY AS A MAJOR PROJECT COMPONENT. NATURAL AND CAPTIVITY-INDUCED (IE STRESS-RELATED) PATHOLOGIES WILL BE IDENTIFIED, SCREENING TECHNIQUES DEVISED, AND USE OF DRUGS STUDIED. PROJECT WILL ESPECIALLY BENEFIT TAIWAN AND THE PHILIPPINES, WHOSE MILKFISH INDUSTRIES DEPEND ON THE CAPTURE OF WILD JUVENILES.