Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was ...Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was verifi ed by monitoring larvae and juveniles of knownage.The results revealed that lapilli and sagittae developed before hatching,and the first otolith increment was identified at 2 days post hatching in both.The shape of lapilli was relatively stable during development compared with that of sagittae;however,growth of four sagittae and lapilli areas was consistent,but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface.Similarly,the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length,respectively.Moreover,daily deposition rates were validated by monitoring knownage larvae and juveniles.The increase in lapilli width was 1.88±0.080 0μm at the ninth increment,which reached a maximum and the decreased gradually toward the otolith edge,whereas that of sagittae increased more slowly.These results illustrate the developmental biology of S.davidi,which will aid in population conservation and fish stock management.展开更多
Feeding growth test of Xenocypris davidi Bleeker was carried out in outdoor ponds for 8 weeks.Three experimental group feeds were made by adding bee pollen to the basic feed at the dosage of 1%,2%and 3%,with fish meal...Feeding growth test of Xenocypris davidi Bleeker was carried out in outdoor ponds for 8 weeks.Three experimental group feeds were made by adding bee pollen to the basic feed at the dosage of 1%,2%and 3%,with fish meal,soybean meal,cotton meal and vegetable meal as protein source,and soybean oil as fat source for basic feed.The results showed that the sexual maturation rates of the parent fish in the bee pollen group with the addition of 2%and 3%were signi ficantly higher than that in the control group and the bee pollen group with the addition of 1%(P<0.05).From the perspective of egg quality,egg diameter,fertilization rate,hatching rate and the length of membrane larvae in the control group were significantly lower than that in the bee pollen group(P<0.05).From the perspective of sperm quality,the addition of high proportion of bee pollen in the diet of parental fish can significantly improve the reproductive performance of male parental fish(P<0.05).Compared with the control group,the addition of 2%bee pollen increased sperm density by 45.3%,sperm motility by 12.7%and the rate of sperm malformation by 21.0%.All things considered,the best amount of yellowtail was 2%bee pollen.展开更多
基金Supported by the Double Branch Plan of Sichuan Agricultural University(Nos.03571421,03571779)
文摘Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was verifi ed by monitoring larvae and juveniles of knownage.The results revealed that lapilli and sagittae developed before hatching,and the first otolith increment was identified at 2 days post hatching in both.The shape of lapilli was relatively stable during development compared with that of sagittae;however,growth of four sagittae and lapilli areas was consistent,but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface.Similarly,the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length,respectively.Moreover,daily deposition rates were validated by monitoring knownage larvae and juveniles.The increase in lapilli width was 1.88±0.080 0μm at the ninth increment,which reached a maximum and the decreased gradually toward the otolith edge,whereas that of sagittae increased more slowly.These results illustrate the developmental biology of S.davidi,which will aid in population conservation and fish stock management.
基金Supported by Jiangxi Science and Technology Program(20141BBF60036)the National Public Welfare Industry(Agriculture)Research Project(201303056-6)~~
文摘Feeding growth test of Xenocypris davidi Bleeker was carried out in outdoor ponds for 8 weeks.Three experimental group feeds were made by adding bee pollen to the basic feed at the dosage of 1%,2%and 3%,with fish meal,soybean meal,cotton meal and vegetable meal as protein source,and soybean oil as fat source for basic feed.The results showed that the sexual maturation rates of the parent fish in the bee pollen group with the addition of 2%and 3%were signi ficantly higher than that in the control group and the bee pollen group with the addition of 1%(P<0.05).From the perspective of egg quality,egg diameter,fertilization rate,hatching rate and the length of membrane larvae in the control group were significantly lower than that in the bee pollen group(P<0.05).From the perspective of sperm quality,the addition of high proportion of bee pollen in the diet of parental fish can significantly improve the reproductive performance of male parental fish(P<0.05).Compared with the control group,the addition of 2%bee pollen increased sperm density by 45.3%,sperm motility by 12.7%and the rate of sperm malformation by 21.0%.All things considered,the best amount of yellowtail was 2%bee pollen.
