Artificial propagation and larval rearing of the Grouper (Epinephelus coioides Ham.(1822)) -Preliminary ivestigation on hommor propagation in netcage (in Mahshar estuary)

Abstract

For the first time in Iran artificial propagation and larval rearing of one native species marine fish, Grouper (Epinephelus coioides) orange spont was done during - 1397 .For estabishing marine fish farm site selection in Ghazaleh estuary in Mahshar was done. Estabishing netcages and wild spawner were caught and transfered there. Also marine hatchery farm containing spawning tank, trough, rearing larvae tank and live food unit were built. Because Grouper is hermaphrodite protogenos , it was difficult to provide enough male wild spawner naturally , so implantation technique was used for sex reversal. Successfully in supplying needed male spawner for propagation. In spawning season (April May) at 21-25 oC temperature two methods was used. 1. Induce spawning by injection Hormone HCG (1395) 2. Induce spawning without Hormone using by concrete spawning tank in natural condition (1397) all stages of propagation containing (ovaltion, fertilization, lraval production and final food larvae and fingerling production, sex reversal) was successful. In sex reversal the best method was 17 α metyltestostorn capsule Hormoneinplantation abdoman s fish whose suitable size was 5-6 kg .In artificial propagation, at 24-hour interval two Injection with HCG Hormone by 750 IU per kg fish was done. Spawner was started 24-hour after 2nd injection in large amount with bad quality and poor fertilization rate. In semi artificial spawning (without hormone ) in spawning tank was gradually and from April at 2-25oc temperature to May 28-30oc temperature. Suitable water temperature for growth of larvae was (23-25oc) and survival rate was (% 29-1/2). The lravae were fed with small size rotifer (80-150 µ) on first week, with 10 rotifer /ml, and large size of rotifer (150-280 µ) on 20th day, artemia salina on (20-25)th day and after 30th day with minced meat. Finally fingerling reached to 9 gr in 80th day.