UPV Digital RepositoryUPV-DRUniversity of the Philippines Visayas
 

Undergraduate Theses

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13

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Committee Chair: search.filters.chair.Torres, James L.Committee Member: search.filters.committeemember.Geduspan, Jane S.

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    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.
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    Toxicity of the aqueous leaf extract of datilis (Muntingia calabura) on the fry and fingerling of Oreochromis niloticus
    Cagampang, Ma. Hazel C. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-08)
    A 96-hour static bioassay on the effects datilis (Muntingia calabura) leaf extract on the fry and fingerlings of Oreochromis niloticus was conducted to determine the Average Median Lethal Concentration (LC50) of datilis (Muntingia calabura) leaf extract on the fry and fingerlings of Oreochromis niloticus and to describe the behavioral responses of the fish to the extract. The assay consisted of six treatments: 0, 12.5, 25, 50, 100, and 200 ppm concentrations of the extract. Physico-chemical conditions (e.g. temperature, pH, salinity, dissolved oxygen, ammonia, nitrite, and hardness level of water) were monitored. Results showed that the average LC50 at the 12, and 24- hour period of the extract in fingerlings (128.61 and 92.37 ppm) were significantly higher (P<0.05) than in the fry (65.45, and 60,99) respectively. Mortality was higher at higher concentrations than at lower concentrations of the extract. Highest mortality was in 200 ppm followed by 100 ppm, then 50 ppm. No death occurred in 0, 12.5 and 25 ppm concentrations of the extract. Mortality was also significantly higher (P<0.05) in fingerlings than in fry. The fish, exhibited avoidance - response reaction and loss of equilibrium. Possibly, the death and unusual behavior manifested by the fish may be due to saponins present in the extract. Physico—chemical conditions were within the tolerable range for the fish hence, these may not have contributed to the death of fish. This study provides preliminary data on the toxic effects of the aqueous leaf extract of datilis on the fry and fingerlings of ?Oreochromis niloticus.