A Publication of the Fisheries Research Institute, Department of Fisheries, Malaysia

***Vol.4 No:2 (December **1999)

Genetic Variability  in the John's Snapper as in Three Different Locations
by
Roslina Ahmad Nawawi, Ismail Awang Kechik and Yosni Bakar
Fisheries Research Institute
11960 Batu Maung, Pulau Pinang,
Malaysia.


John's Snapper is becoming one of the important cultured fish species in Malaysia.  Therefore, information on the level of genetic variability of John's snapper stocks is useful  for effective breeding programme. The Random Amplified Polymorphic DNA (RAPD) fingerprinting  technique  was used in this study to assess the level of genetic variation in John's snapper from three different locations in Peninsular Malaysia. Six primers were used in this study (OPA-08, OPA-09, OPA-11, OPA-18, OPAB-05, OPBC-10). The similiarity matrix of population from Penarak-Glugor was high (0.9188)  compared with similiarity matrix of population from Semerak-Penarak (0.8455) and Semerak-Glugor (0.8647).

Induced Breeding and Early Life Development of
Golden Snapper
(Lutjanus johnii) Larvae
by
Nik Daud Nik Sin and
Nik Razali Nik Lah
Marine Finfish Production and
Research Centre,
Tanjong Demong, Besut, Terengganu, Malaysia.


The golden snapper (
Lutjanus johnii), also known as John's snapper, is a popular food fish in Malaysia. The golden snapper, a very attractive fish, has a golden body and creamy underbelly. It may be distinguished from other Lutjanids by its golden colour and distinct dark spot on each scale, forming longitunidal rows of dark streak throughout the body. Snapper are classified as 'generalised carnivores', which means they eat a wide variety of animals, including many types of fish, crustaceans, worm and molluscs. Snapper are a reef fish. The fish is found in coastal areas and may be caught occasionally in large schools with trawl in shallow areas in the North Andaman Sea and the South Chinese Sea. At present, the golden snapper together with other Lutjanids is the third most important farm fish next to grouper and seabass in Malaysia. The attempt on induced breeding of golden snapper was conducted since 1990. The series of study was conducted to refinement the breeding technology of the species.Induced spawning was done by selection of female brooder with egg diameter more than 0.35 mm and male brooder with running milt under light abdominal pressure. Spontaneous spawning occurred 35 hours after hormonal injections with HCG at a dose of 250 IU/kg and 500 IU/kg for male and female respectively. A total of 1.0 million eggs were collected with fecundity of 0.5 x 106 egg/female. The embryonic development of John's snapper occurred rapidly and the hatching occurred 14 hours after fertilization at 30°C and 32 ppt. The newly hatched larvae measures from 1.75 - 1.85 mm (1.81 ± 0.04) with a yolk sac and oil globule at 0.005 - 0.007 mm3 (0.007 ± 0.001) and 0.005 - 0.007 mm3 (0.006 ± 0.001) respectively. Absorption of the egg yolk started 1 hour after hatching and completely disappeared after 38 hours. Meanwhile, the oil globule takes longer time and completely disappeared at 43 hours. The mouth of the larvae opened by day 2 at 46.78 hour with size from 2.58 - 2.78 mm (TL).

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