TY - THES TI - The radiosensitivity of nile tilapia (Oreochromis niloticus) fingerlings AB - The nile tilapia (Oreochromis niloticus), a very popular fish commercially in the Philippines, was studied to determine its radiosensitivity and to see its potential as a biological indicator in aquatic ecosystems. Nile tilapia was seen to be radiosensitive. The fish were exposed to gamma-irradiation and chromosomal aberrations were induced. The various types of aberrations seen were chromatid gaps, chromosome gaps, chromatid fragments, dicentric rings, fusions, despiralizations and translocations. Among the aberrations observed, dicentric rings, fusions and chromosome gaps were strongly correlated with dosage, with only the dicentric rings increasing steadily with increasing dosage. In the course of the study, the lethal dosage{sub 50} for nile tilapia with 18 days was determined and it was observed at 2.0 krad. The modal chromosome number was also established at 2n=44 with a karyotype exhibiting 22 pairs of acrocentric chromosomes with 2 pairs of marker chromosomes present. (Author) AU - "Reyes, Michael Joseph T" AU - "Velasco, Pia Victoria V" KW - "63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS" KW - "AQUATIC ECOSYSTEMS" KW - "BIOLOGICAL INDICATORS" KW - "BIOLOGICAL RADIATION EFFECTS" KW - "CHROMOSOMAL ABERRATIONS" KW - "DICENTRIC CHROMOSOMES" KW - "EXPERIMENTAL DATA" KW - "FISHES" KW - "GAMMA RADIATION" KW - "KARYOTYPE" KW - "LETHAL RADIATION DOSE" KW - "NUMERICAL DATA" KW - "PHILIPPINES" KW - "RADIOSENSITIVITY" DO - https://doi.org/ UR - https://www.osti.gov/etdeweb/servlets/purl/20073994 PB - CY - Philippines PY - 2000 DA - 2000-04-01 LA - English J2 - [] VL - C1 - University of the Philippines, Manila (Philippines), College of Arts and Sciences, Dept. of Biology C2 - C3 - INIS-PH-010 C4 - C5 - Available from INIS in electronic form; Also available from PNRI library L3 - Other Information: TH: B.S. Biology; 33 refs, 12 figs, 5 tabs, 9 plates; PBD: Apr 2000 ER -