The egg development and morphological development of larvae and juveniles of crucian carp, Carassius auratus (Linnaeus) caught at Bosung River, Chollanam-do, in April to June, 1999 were investigated in the laboratory, Yosu National University.
In the...
The egg development and morphological development of larvae and juveniles of crucian carp, Carassius auratus (Linnaeus) caught at Bosung River, Chollanam-do, in April to June, 1999 were investigated in the laboratory, Yosu National University.
In the spawning season, the nuptial organ was appeared on the opercular region and under region of eye, pectoral fin, ventral fin and lateral line. The egg was transparent of yellowish brown color, demersal of adhesive and sperical in shape, measuring 1.49∼1.63㎜ (mean 1.57㎜, n=50) in diameter. The first hatching was occured in 75 hours 10 minutes after fertilization in water temperature 18.3∼21.7℃. Newly hatched larvae attained mean 4.28㎜ had a big yolk sac and their mouth, and anus were not opened yet. At 5 days after hatching, the larvae attained mean 5.34㎜ and the yolk sac was almost absorded. At 13 days after hatching, the larvae attained mean 7.21㎜. The caudal notocord was flexed 45°upward, and they reached post larvae stage. At 31 days after hatching, the larvae, mean 14.68㎜ in TL reached the juvenile stage with all of the fins formed with complete set of the fin rays (D. ⅩII-11∼15; A. Ⅲ-5∼6; P. 15∼16; V. 1-8).