Peranan Hipofisa dalam produksi benih ikan

Hypophysis or pituitary gland is an endocrine mastergland which can be found throughout the vertebrates. In fish, the gland is situated between the posterior of nervus opticus and the anterior of saccus vasculosus. This gland can produce gonadotrophic hormon (gonadotropin) which indirectly influences the gonadal maturation, by stimulating the production of sex steroids (androgens, estrogens, and progesterons). Due to its gonadotropin content, hypophysis is now widely used in many hatcheries as a spawning inducer. The spawning method is commonly termed as hypophysation technique. The procedures of this technique include : selecting offish breeders ; dissecting, collecting, extracting of hypophysis; hormon injection, and spawning. The success of hypophysation depends on how a proper donor and recipient fish are selected. The donor fish should be taken prior to spawning season to ensure the high content of gonadotropin. Recipient fish should be mature in gonad condition or at least the eggs have filled with yolk. Only good and healthy fish are choosen. The other important aspect is the breeders handling technique. The handling of the breeders should be done carefully and be avoided from physical damage. The hormon should be given at suitable dosage which correlate with gonad maturation stage. The ripe gonad requires lower dosage than the immature one. More accurate method for determining gonad maturation is by biopsy method rather than by morphological character. The procedure of biopsy, eggs hatching and larvae rearing are described in this paper.