| A successive observation was conducted to study the embryonic larval and juvenile development of Procypris rabaudi (Tchang) from Aprl4 to July 20, 2005,and 37developmental stages of the embryos were described and illustrated. The eggs, measuring 1.5-1.8 mm in diameter, were demersal strongly sticky, almost spherical in shape, transparent and unpigmented, with a pale yellow yolk and no oil globule and 2.3 - 2.5 mm after absorbing water. Hatching occurred 90.34-118 h after fertilization at 17.4-23°C. The newly hatched larvae,measuring 6.4±0.1 mm in total length (TL) averagely,had melanophores on the body with (29-30) +(15-16) =(44-46) myomeres,yolk sac,pyriform in shape,extremely lift of head,its lowest temperature is about 12.35℃,and the accumulative temperature of 76-99.3℃-d is necessary.The general procedure of embryo development in Procypris rabaudi (Tchang) is similar to that of cyprinoid, but for the former, hatching has not a direct bearing on the temperature, as in the laboratory temperature there will appear the phenomena of hatch delaying ,and the black pigment in eyes and primary pectoral fin have been appearing. The embryonic development stage does not have tail vesicle.appearance of hatching gland indistinctly,but has more myomere at hatching.According to morphological characters and ecological character of postembryonic development of Procypris rabaudi (Tchang),four phases were devidided as yolk-sac stage ,late-larvae stage.early juvenile and late juvenile stage from larvae to juvenile at 21-27°C of water temperature. 20 developmental stages of the postembryonic development were described and illustrated, and the accumulative temperature of 1940.25 ℃·d is necessary.The yolk was completely absorbed at 11.8 mm TL. Notochord flexion was initiated at 9.5 mm BL and finished at 11.0 mm BL. Aggregate numbers of all fin rays were completed at 9.2 mm BL. Squamation was initiated on the caudal peduncle at 20.62 mmTL and completed at 48.81 mm BL. The eggs of Procypris rabaudi (Tchang) is bigger than those of the closely related species carassius auratus and Cyprinus carpio. The larvae and juveniles of Procypris rabaudi (Tchang) weresimilar to those of the latter species in general morphology, especially the presence of body melanophores in newly hatched individuals and a distinctive lateral streak on the lateral body during the period of postflexion larvae. However,early yolk sac larvae of Procypris rabaudi (Tchang) were more similar to Cyprinus carpio than carassius auratus in having a cement organ on the forehead. Larvae and juveniles of Procypris rabaudi (Tchang) differed from those of the latter two species in pigmentation on the ventral body surface at hatching and around the mouth during the period from preflexion to early postflexion larvae and in having 12-13 dark lateral streaks or bands on the body in postflexion larvae and juveniles.Growth regression showing that the speed of Procypris rabaudi (Tchang) is no less than Cyprinus carpio, and allometry pattern.The correlation equation between age (number of days) and totle length(L) ,body length(l) and weight(W) of larvae Procypris rabaudi (Tchang) as follow: 1= 0.388T + 6.4945, R2 = 0.9869, L = 0.5506T + 6.9603,R2 = 0.987, W =0.0323T2.386 ,R2 = 0.9734. The correlation curve between totle length ,body length and weight of larvae juvenile Procypris rabaudi (Tchang) as follow: W =0.006113.3537,R2=0.9674, W =0. 0029L3.2937 , R2 = 0.9784.Absolute growth rate: 0.39, 0.29, 0.53, 0.39 and 0.31mm;special growth rate: 5.26, 3.25, 4.22, 1.99 and 1.05%d-l. The tendency between (body high,head lenth,preanul and postanul length )/body length with body length express that morphological changes is correspondent with ecological characters about stage subdivisions from larvae to juvenile,while difference to growth characters.Histological study indicates that the chronology of organogenesis is correspondent with observing under dissecting microscope, but the timing of organogenesis is earlier than the latter. Advanced differentiation belongs to nerve, locomotion and circulation system ,simple differentiation also to others systems, while immune system appearance relatively late. This is the fist report about organogenesis of Procypris raftawaf/(Tchang),such as cement glands, hatching glands, chloride cells, neuromasts and prenephric development as well.
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