UPV Theses and Dissertations
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Item The effect of different feeding schemes on mudcrab Scylla serrata larvae fed with Artemia salinaBachoco, Anabelle M. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1998-04)The study on the effect of different feeding schemes of mudcrab Scylla serrata fed with Artemia salina was conducted to identify the zoeal stage of S. serrata where an addition of Artemia to the diet results to higher survival, shorter intermoult duration, higher growth index, and shorter metamorphosis to the megalopa stage. All treatments were fed with Brachionus at a density of 20 ind./ml. Results showed that larvae fed with Artemia from day 0 had consistently high percent survival and this is significantly higher compared to other treatments. This was followed by larvae fed with Artemia at day 3 and at day 6. However, statistical analysis showed that there is no significant difference between the two treatments. Significantly low percent survival was obtained on larvae fed with Artemia at day 9. Results also showed that larvae fed with Artemia at day 0 metamorphosed to megalopa stage after 18 days and obtained the shortest average intermoult duration of 3.6 days and highest growth index of 5 6. This was followed by larvae fed with Artemia at day 3, day 6, and day 9. Artemia has high nutritive value which contributed to high survival, shorter intermoult period, high growth index and shorter metamorphosis period up to the megalopa stage.Item Larval rearing of Scylla serrata Forskal: The effect of Artemia salina and Brachionus plicatilis as food on the growth and survival of zoeaApote, Ma. Noemi G. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1996-11)A study was conducted to find out tile effects of Artemia, Brachionus and a combination of Anemia and Brachionus as food on the survival of mudcrab Scylla serrata Forskal zoea and the ability of the zoea to metamorphose to megalopa stage. The study composed of three experiments. Each experiment lasted for 21 days. Results showed highest mean percent survival (66.7±2.03) on zoea fed with a combination of Anemia and Brachionus at a feeding density of 5 individuals/ml each. When the density of Brachionus was increased from 5 individuals/ml to 12 individuals/ml in the combination diet, there was an increase in the survival of the zoea to 68.9±2.41. Highest metamorphosis from zoea to megalopa was also obtained on those fed with a combination of Anemia and Brachionus. This combination diet also gave the shortest number of days for the zoea to metamorphose to the next stage which also resulted to the least number of days for megalopa production to start. The study also revealed that larvae ted with a combination of Anemia and Brachionus reared at 30 ppt salinity got high survival on the first three days of culture, however starting on the 4th day up to the 15th day of culture, those reared at 28 ppt obtained higher survival although not statistically different from the other salinities tested.Item Effects of sodium iodide-enriched brine shrimp (Artemia salina) on the growth, survival and metamorphosis of rabbitfish (Siganus guttatus) bloch larvaeCabanilla-Legaspi, Ma. Irene C. (University of the Philippines Visayas, 2018-06)Metamorphosis is considered the most crucial stage in larval fish development that dictates the overall larval fish survival and production output in a hatchery system. This physiological process is modulated by thyroid hormones produced from the thyroid gland the biosynthesis of which is dependent on the supply and availability of the mineral iodine. The present study evaluated the supplementation of iodine to rabbitfish (Siganus guttatus) larvae to determine the influence of this mineral on thyroid hormone levels, metamorphosis, growth performance, stress tolerance and survival. To efficiently deliver iodine to the larvae, the enrichment protocol was optimized by exposing the Artemia to increasing concentrations of this mineral (0.05 g L-1,0.1 g L-1, 0.2 g L-l, 0.4 g L-1 and 0.8 g L-1). The best iodine enrichment treatment was selected (0.8 g NaI L-1) and used to evaluate the influence of this mineral on larval development, growth, metamorphosis, stress tolerance and survival. Results suggest that growth of rabbitfish in terms of body weight was higher in the treated group (0.20±0.01g) as compared to the control group (0.14±0.01g). This significant growth response is associated with accelerated period of metamorphosis by 11.2 days and a lower muscle fiber count in the treated group (0.003±0.005 μm2-1). Higher levels of triiodothyronine (T3) and thyroxine (T4) were also observed in the group receiving the iodine-enriched Artemia that coincides with the larvae’s accelerated period to metamorphose. T3 in the treated group (15.31±1.22 ng g-1) is higher compared with the control (8.67±1.5 ng g-1) and T4 in the treated group (459.25±136.9 ng g-1) is also higher compared with the control group (170.86±92.55ng g-1) at 27 days after hatching which coincides with the onset of metamorphosis leading to early metamorphosis of larvae in the treated group. In addition, the present results showed that the larvae in treated group were significantly tolerant to stress, quantified as the cumulative stress index (15.33±2.40 CSI) indicating the positive response of the larvae to the dietary iodine enrichment. In summary, sodium iodide-enriched live food (Artemia) accelerated rabbitfish larvae metamorphosis, improved growth and stress tolerance in rabbitfish larvae. The results of this study can be used as a model iodine enrichment protocol to improve the hatchery output of other high-valued marine fish species in culture.