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Abstract : |
In order to study the early development stages, eggs and milts were obtained from the ripe specimens of M. cavasius. For females stripping was done after 6 h of 10 mg kg 1 body weight carp PG extract injection. Then the eggs were fertilized in the laboratory and subsequent development stages were studied. The average diameter of fertilized eggs were observed to be 0.5 mm. First cleavage (two cell), four cell, eight cell and multi cell stages were observed after 00:40, 00:55, 01:10, 02:50 h of fertilization, respectively. Morula, gastrula and yolk plug stages were found 4, 6 and 7 h after fertilization. Notochord was slightly observed after 8 h of fertilization. Head and tail were differentiated after 09:30 h of fertilization. Hatching occurred within 19+2 h after fertilization and larvae were measured 1.28 mm, when the water temperature was 27 to 29.5أƒâ€ڑأ‚آ°C. The newly hatched larva was devoid of mouth, dorsal, ventral, pectoral fin and pigments. Barbel appeared to be slightly visible in the larva just after 6 h of hatching and clearly visible after 12 h of hatching. The yolk sac was completely absorbed when the larva was 48 h old. All the morphological and other organal development occurred within 12 days of post larval period., |
