Undergraduate Theses
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13
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Item Utilization of morphometric and meristic characteristics to identify cultured Tilapias (Oreochromis spp.)Caipang, Christina Joy Rossetti A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1995-03)Meristic characters (DSC, DFRC, AFRO, CFBC and GRC) and morphometric characters (SL, HL, BD, CD and IOW) were utilized to identify five small-sized, with standard lengths ranging from 55- 100 mm., and five big-sized tilapia populations, with standard lengths ranging from 110-195 mm., of forty samples each. Dorsal spine count (DSC) is the least variable while the caudal fin bar count (CFBC) is the most variable meristic character in the tilapia species studied. Analysis of variance (ANOVA) showed that all meristic characters have highly significant differences (p<0.01) among the big-sized tilapias; while in the small-sized tilapias all have highly significant differences (p<0.01) except in caudal fin bar count which was not significantly different (p>0.05). Data on morphometric characters were log-transformed and the four other characters (HL, BD, CD and IOW) were divided by the standard length (SL) to eliminate the effect of size. ANOVA showed that all morphometric characters have highly significant differences (p<0.01) in the big-sized group. Likewise, in the small-sized tilapia species, all morphometric characters have highly significant differences (pU.O5). The study also confirmed that tilapia species studied are morphometrically and meristically distinct.Item Embryonic development and hatching rate of grouper (Epinephelus suillus) eggs incubated at different stocking densitiesBofill, Aileen B. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1992-04)Fertilized eggs of the grouper Epinephelus suillus were obtained from natural spawning of broodstock reared in a 50—t concrete tank at the Aquaculture Department of the Southeast Asian Fisheries Development Center, Tigbauan, Iloilo. The development of eggs incubated at three different stocking densities (50, 1OO, and 150 eggs/1) were monitored. Hatching rates in the different treatments were also determined. Fertilized eggs were floating, non—adhesive, transparent, and spherical in shape with a mean diameter range of 0.83 — 0.84 mm. The yolk was colorless, transparent, and possessed a single oil globule of 0.22 mm in diameter. The eggs have developed into the 2—cell stage 45 min after stocking. Eggs incubated at 1OO eggs/1 hatched 24 h after stocking, while hatching occurred after 27 h and 5 min at 50 eggs/1. No hatching was observed at 150 eggs/1 stocking density even after 28 h post—stocking. Water temperature and salinity during the experiment were 27 ° C and IB ppt, respectively.
