Journal of Dalian Ocean University  2023, Vol. 38 Issue (6): 972-979 DOI: 10.16535/j.cnki.dlhyxb.2023-094 |
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| Observation of early development and determination of the point of no return (PNR) in Chinese hook snout carp (Opsariichthys bidens) |
| XING Yuxin，LUO Xiaonian*，LI Jiao，DUAN Youjian，JI Chenyue，CHANG Jiantai
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| 1.College of Fisheries and Life Science，Dalian Ocean University，Dalian 116023，China；2.Key Laboratory of Fish Applied Biology and Aquaculture in North China，Liaoning Province，Dalian 116023，China |
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Abstract In order to probe into the developmental characteristics of early development and to determine the point of no return (PNR) in Chinese hook snout carp (Opsariichthys bidens), the morphological characteristics of early development and the effects of starvation on the growth, morphology and behavior were investigated in Chinese hook snout carp larvae from 1 day post hatching (dph) to 43 dph juveniles at water temperature from 20.5 ℃ to 26.0 ℃. The newly hatched larvae derived from artificial breeding were reared indoor and 9 dph postlarvae were reared and fed zooplankton in a 0.67 hm2 pond to observe the developmental characteristics and to determine the PNR. The results showed that 10 days old Chinese hook snout carp had initial feeding, with the mixed nutrition from 10 to 11 days old, completely exhausted yolk sac at 12 days old, and the first scales at 27 days old, fully covered scales at 43 days old. Thus, the Chinese hook snout carp larvae were divided into early fry (from 0 day old to 11 days old), late fry (from 12 to 26 days old), and juvenile stages (27 to 43 days old). The starvation and re-feeding test revealed that Chinese hook snout carp larvae had PNR at 12 days to 13 days old, and all died at 14 days old under starvation stress at water temperature of (21.5±1.0)℃. The finding indicated that Chinese hook snout carp as a fish species with late exhaustion of yolk sac was benifit to better adapt to the ecological environment in the wild, and that Chinese hook snout carp had only 2 d mixed nutrient period, and needed to be stocked into the pond at the right time, so as to improve the survival rate of the fry.
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Published: 18 January 2024
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