Observation of skeletal system development of larval and juvenile Amur sturgeon Acipenser schrenckii
GAO Linan1,2, HU Hongxia2*, WANG Wei2, DONG Ying2, WU Lixin1
1.College of Fisheries and Life Scence，Dalian Ocean University, Dalian 116023, China; 2.Key Laboratory of Fishery Biotechnology, Beijing Fisheries Research Institute， Beijing 100068, China
Abstract: In order to improve the understanding of skeleton growth and development of Acipenseriformes, and to explore the adaptive evolution of the only existing chondrostean, skeletal system of Amur sturgeon Acipenserschrenckii was continuously observed from newly hatched larvae to juvenile fish using the cartilage-bone double staining technique, and the growth and development schedule was summarized according to the ossification time of skeletons. No obvious differentiation of bone elements was observed in the newly hatched larvae, and skeletal elements were mainly distributed only on the head, and then notochord and fins, without ossified bones. The juvenile Amur sturgeon turned into rapid growth stage, neurocranium, splanchnocranium and appendicular skeleton developed rapidly, and the skeleton in all parts of the body were basically formed at 10-15 days post hatched (dph). At 20 dph, the maxilla, dentary and teeth began to ossify; at 24 dph, the parietal, posttermporal, suboperculum, scapula and the lateral part of dorsal scute appeared to begin to ossify; at 26 dph, the scapula, dorsal scute was completely ossified, and the pterotic, clavicle and cleithrum began to ossify at the same time. At 28 dph, jugal, frontal and spina of the pectoral fins began to ossify. At 30 dph, the postorbital began to ossify; the lateral scute was completely ossified. At the juvenile fish stage, the framework of skeleton was basically developed. The ossiculi rostralia, ventral scute, and the radialia of pelvic fin, anal fin, dorsal fin, and pectoral fin were ossified completely. In conclusion, the bone development of Amur sturgeon began after hatching, and the bones related to breathing (arcus mandibularis), feeding (arcus branchialis) and swimming ability (fins) were developed preferentially during the development, and the order of bone ossification was approximately consistent with that of development. The ossified bone was first observed at 20 dph, with the peak ossification at 24-30 dph, and the ossification time being involved in the breeding environment, heredity and other factors. In this study, there was 10 days difference in the bone ossification initiation time in different batches of artificial spawning in Amur sturgeon.
2021, Vol. 36 
