Effects of water acidity on the hatching rate and yolk fry survival rate of some freshwater fishes
2000
Jirachai Juntana | Jureerath Songnoy | Pradit Petcharoon (Department of Fisheries, Bangkok (Thailand). Pattani Inland Fisheries Development Center)
Nine species of freshwater fishes were tested the effects of water acidity on the hatching rate and survival rate of the 48 hour incubated yolk fry. Increasing in water acidity values were significant negatively (p0.05) effected on hatching and the survival. The eggs and yolk fry of Anabas testudineus Bloch were found to be the highest tolerance to water acidity. The hatching rate and the survival rate of the lowest pH values of 4.5 and 5.1 respectively were not significantly different from controls (rain water). Other species of fish such as Trichogaster pectoralis (Regan), Mystus nemerus (Cuv. & Vul.), T. trichopterus (Pallas), Clarias macrocephalus Gunther, C. gareipinnus (Burchell), Labeo rohita (Hamilton), Barbodes gonionotus (Bleeker) and Leptobarbus hoeveni (Bleeker) were found that the minimum pH values for their egg incubation were 4.8, 4.8, 5.1, 5.2, 5.2, 5.2, 5.3 and 5.3, respectively. In the incubation of yolk fry, the pH values of these fishes were found to be 5.3, 5.5, 5.5, 5.3, 5.3, 6.2, 6.1 and 5.9 respectively.
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