Early developmental stages of Nandus nandus (Ham.)
2002
Das, M. | Tarafder, M.A.K. | Pal, S.
In order to study the early developmental stages of Nandus nandus an experiment wasconducted, where eggs and milt were obtained from the laboratory reared N nandus bystripping after 15 hours of 150 mg/kg body weight of carp PG extract injection. Then theeggs were fertilized in the laboratory and subsequent developmental stages were studied.First cleavage (two cell), four cell, eight cell, sixteen cell and multi cell stages were found30, 50, 70, 105 and 160 minutes after fertilization respectively. Morula, early gastrula,middle gastrula, late gastrula and yolk plug stages were found 5, 8, 9, 11 and 13 hoursafter fertilization respectively. Hatching occurred within 20±2 hours after fertilization,and larvae were measured 1.60 mm in diameter. After one hour of hatching twomelanophore bands were found at the caudal region of the body of the larvae. Eyes werefirst observed in l 0 hours, pectoral and pelvic fin buds appeared in 22 hours and welldeveloped in 38 hours old larvae. Mouth cleft and brain lobes were visible when thelarvae were 34 and 38 hours old respectively. Myomeres partially appeared in 16 hours,which were clearly visible in 74 hours old larvae. Larvae started wandering and searchingfor food after 56 hours of hatching. The yolk sac was completely absorbed when larvae became 62 hours old.
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