ANTISOMATOSTATIN-INDUCED GROWTH ACCELERATION IN CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA)

Since somatostatin (SRIF) inhibits the release of growth hormone (GH), its immunoneutralization may provide an alternative to GH therapy as a means of enhancing somatic growth in fish. The present study examine d the feasibility of accelerating growth in juvenile chinook salmon by means of antiSRIF administration. Yearling salmon of Nicola River sto ck (BC, Canada) were injected intraperitoneally every 5 days, for a to tal of 40 days, with either SRIF (1 mu g g(-1) body wt.), antiSRIF (SO MA-10, 1 mu g g(-1)), recombinant bovine GH (rbGH, 2.5 mu g g(-1)), re combinant porcine GH (rpGH, 2.5 mu g g(-1)) or saline (controls). No s ignificant differences were observed in length, weight or final condit ion factor (k) between the SRIF-treated and control fish over the expe rimental period. However, the fish treated with the antiSRIF were sign ificantly (p less than or equal to 0.05) longer and heavier than the c ontrol salmon after 25 and 30 days respectively. Furthermore, antiSRIF treatment caused a lowering in k when compared to the control salmon. Fish injected with rbGH or rpGH were significantly longer and heavier than all other groups (p less than or equal to 0.05), after only 5 da ys. GH treated groups also returned higher k when compared against all other treatments (p I 0.05). No differences were observed in growth b etween the two rGH treatments over the experimental period.