Abdul Rashid, Mohd Kamil

Olubunmi, Akinfolajimi

Orosco, C. A.

Zainal Abidin, Aizam

Universiti Putra Malaysia Institutional Repository

UPM Research Report 1998: Volume 2THE EFFECTS OF DIFFERENT REARINGCONDITIONS ON THE GROWTH AND SURVIVAL OFPENACUS MERGUIENSIS JUVENILESO. Akinfolajimi, Z.A. Aizam, M.K. Abdul Rashid andC.A. OroscoFaculty of Applied Science and TechnologyUniversiti Putra Malaysia Terengganu, Mengabang Telipot,21030 Kuala Terengganu, MalaysiaKeywords: Penacus merguiensis, juveniles, growth,survival, circular tanks and raceways.IntroductionThe nursery system has been incorporated into the shrimpculture industry in many countries because of its inherent ad-vantages all of which enable managers to more accuratelypredict survival, standing crop, feeding rates and productionlevels in grow-out ponds (Wyban and Sweeny, 1991; Stum-ner et al. 1992). This research was therefore conducted inother to determine the effects of rearing Penaeus merguiensisjuveniles under different rearing conditions by studying theeffects of utilizing algal supplements and commercial pelletsas feed supplements in nursery rearing of P. merguiensis andthe effects of different stocking densities on the growth, sur-vival and production of P. merguiensis in raceways.Materials and MethodsPostlarvae were stocked into 400 1 round tanks containing300 1 filtered seawater from PL 10 at 1,200 PL 1 tank andreared till PL 28 under three treatments; treatment A con-sisted of feeding the PLs with trashfish and commercial pel-lets in a clear-water rearing medium, treatment B consistedof feeding the PLs with trashfish in a medium containingcommercial Spirulina while, treatinent C consisted of feedingthe PLs with trashfish in a medium containing culturedSkeletonema. Another experiment was carried out by stock-ing P. merguiensis PLs at PL 10 into rectangular tanks con-taining 300 1 of seawater at two different densities, 1,200 and2,400 PLs. The PLs were fed with trashfish and commercialpellets. Growth in length and weight were measured everythree days by randomly removing four postlavae from eachrearing tank. The growth, survival and production of the dif-ferent treatments were compared at the end of the experi-ments. F- test statistical analysis was used to test significantdifferences between growth and survival in the treatments.Results and DiscussionJuveniles reared under treatment A had the highest meanspecific growth rate of 14.53. This was followed by a meanspecific growth rate of 12.16 in treatment C although therewas no significant difference between the two treatments.The mean specific growth rate in treatment B was signifi-cantly lower (p <O.OS) than treatment A but not treatment C.The average survival rate followed the same pattern as themean specific growth rate. Mean survival rate was 96.92%and 89.SS% for treatments A and C respectively. Averagesurvival rate of juveniles in treatment B was significantly156(p<O.OS) lower than treatments A and C at 44.39%. These re-sults suggest that the juvenile were capable of deriving somenutrition from the live microalgae (Skeletonema sp.) but notso much from the artificial microalgae (Spirulina sp.). Thenutrition derived from the live microalgae appears to com-pare favourably with that obtained from the commercial pel-lets in terms of growth and survival. The lower coefficient ofvariation for juveniles raised on Skeletonema showed thatgrowth was more uniform for the juvenileswhich could be asa result of better conditions due to the diet fed. Stumner et al.(1992) observed that natural productivity in rectangular tankscan contribute significantly to the nutritional requirement ofshrimp. Algal populations in tanks also reduce ammonia lev-els, which may rise in the presence of high shrimp biomass.Juveniles reared at the lower stocking density of 1,200 larvae(800/m2) had the higher mean specific growth rate of IS.34while the juve~iles reared at higher stocking density of 2,400larvae (600/m ) had a lower mean specific growth rate of 11.82 but the difference was not significant (p<O.OS). The re-sults showed that although growth was faster at the lowers~ocking density, the average survival rate (84.S0%) of juve-mles was lower than that of the juveniles reared under thehigher stocking density where the average survival rate was(90.57%). However, the difference was not significant(p<O.OS). The higher survival rate seen in juveniles reared atthe higher density could be attributed to the more uniformsize of the juveniles because of their lower coefficient ofvariation. Production per tank for the feeding experiment wassignificantly greater in treatment A than for other treatments(p<O.OS) while for experiments in raceways, production forthe 1200 and 2400 PL 1 tank was 61.01 and 61.93 g 1 tankrespectively. Production for the 2400 PL I tank was about thesame as that of 1200 PL I tank and there is no significant dif-ference between them (p<O.OS).ConclusionsProduction was highest for juveniles reared with pellets asfee~ sup~lements al~ough growth and survival was also highfor juveniles reared m Skeletonema medium. Juveniles rearedin tanks gave a better performance than those reared in race-ways under the same conditions. From the results of theseexperiments, it is believed that feeding a combination oftr~hfi.sh and. pellets in a medium containing SkeletonemaWIll gI~e ~pt!mu~ performance in the nursery rearing of P.mergutensts juveniles, It IS estimated from this study that ata stocking density of 3,960 PLs (about 4000 PLs) per ton, alOO-ton tank can produce enough juveniles to stock a 1 hec-tare pond.ReferencesStunner: L.N. and Samocha, T.M. and Lawrence, A.L. 1992. Intensi-fication o~ penaeid ~urse~ systems: In: A. W. Fast and L. I.Lester (editors), Manne Shrimp Culture: Practices and Prin . 1p.321-344. CIP es.Wyban, I.A. and Sweeny,. I.N. ~991. Intensive shrimp productiontec~nology. The Oceanic Institute Shrimp Manual, The OceanicInstitute Honolulu, Hawaii. p. 158.Supported by lRPA Grant 01-02-04-0155

The effects of different rearing conditions on the growth and survival of Penacus merguiensis juveniles

http://psasir.upm.edu.my/20253/1/The%20effects%20of%20different%20rearing%20conditions%20on%20the%20growth%20and%20survival%20of%20penacus%20merguiensis%20juveniles.pdf

The effects of different rearing conditions on the growth and survival of Penacus merguiensis juveniles

Abstract

Similar works

Full text

Available Versions

Universiti Putra Malaysia Institutional Repository