Biological evaluation of frozen zooplankton as food for milkfish (Chanos chanos) fry
Abstract
Milkfish fry with an average standard length and weight of 13.88 mm and 3.95 mg, respectively, were reared for 30 days using live and frozen Moina macrocopa and Brachionus plicatilis at feeding densities of 10–20 individuals per ml. Growth, survival and yield were used as indicators of the overall performances of the various treatment groups. Fry fed live M. macrocopa showed gains (both length and weight), growth and survival rates and yields significantly higher than fry fed with other treatment groups (P < 0.05). However, significant reductions in growth and survival rates resulted when fry were fed frozen M. macrocopa. On the other hand, there were no significant differences in growth and survival rates (P < 0.05) in fry fed live or frozen B. plicatilis.
The results of the current study showed that although milkfish fry could be grown successfully using B. plicatilis, feeding with live Moina significantly improved growth, survival rate and yield (P < 0.05). Frozen Moina was found to be unsuitable as a feed for rearing milkfish fry because it reduced growth rates and increased mortality. Comparisons between live and frozen rotifers have proven the suitability of frozen rotifers as feed for rearing milkfish fry. By freezing surplus rotifers this would permit short term storage in anticipation of high hatchery demand and overcome any unpredictable failures with live cultures.
Citation
Villegas, C. T., & Lumasag, G. L. (1991). Biological evaluation of frozen zooplankton as food for milkfish (Chanos chanos) fry.Publisher
Verlag Paul PareySubject
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- Journal Articles [1046]
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Article
Lactate dehydrogenase isozyme patterns during the development of milkfish, (Chanos chanos (Forskal))
-Kalikasan, The Philippine Journal of Biology , 1981 - University of the Philippines at Los BañosPolyacrylamide disc gel electrophoresis was done to determine the lactate dehydrogenase (LDH) isozyme patterns for fry (5-3 mg), fingerling (6-12 g), pond-size (150-250 g) and adult (6-9 kg) milkfish. The patterns were tissue specific; the different tissues examined, viz., eye, liver, heart, and skeletal muscle had different expressions of LDH isozymes. The resolved patterns appeared to be products of LDH gene loci A, B, and C. Subunits A and B were present in all tissues. A4 and B4 were predominant in skeletal and heart muscle, respectively; the two associated non-randomly in vivo and formed only the heteropolymers A3B and AB3. A liver band, L4, was most conspicuous in the fingerling, pond-size, and adult; it was assumed to be coded by locus C. A negatively charged band, X4, was detected in fully developed ovary and in fry homogenized as whole individuals, but it could not be resolved in tissues of fingerling. Six-mo old stunts and 3-mo old fingerlings had similar LDH patterns for all tissues examined. The patterns for 11-mo old stunts and fingerlings also were similar but the one for the eye of the former was the same pattern resolved for the eye of adults. There was no change in the LDH isozyme patterns of milk fish stunted for 6 mo under different salinity levels (0-5, 15-20, 32-35 ppt). -
Conference paper
Larviculture of marine fishes at SEAFDEC/AQD
- In CT Villegas, MT Castaños & RB Lacierda (Eds.), Proceedings of the Aquaculture Workshop for SEAFDEC/AQD Training Alumni, 8-11 September 1992, Iloilo, Philippines, 1993 - Aquaculture Department, Southeast Asian Fisheries Development CenterThe recent glut in the world market for shrimp dealt a heavy blow to the aquaculture industry. It is thus apparent that fish farmers should not depend on only a single species for culture. The popularity and market demand for grouper, sea bass, and snapper make them obvious choices as alternative culture species. On the other hand, milkfish and rabbitfish are cheaper sources of protein and they already contribute substantially to fish production from aquaculture--56.2% from milkfish for example (Rabanal 1988). However, culture and production of marine fishes are hindered by the unpredictable and seasonal seed supply. Research on larviculture at SEAFDEC/AQD are geared towards hatchery production of fry to augment supply from the wild.
