With the technology of morphology, histology and nutrition, the characteristics of organ development and the source and demand of nutritional at different stages in post-embryonic （water temperature 3-14℃） of Hucho...With the technology of morphology, histology and nutrition, the characteristics of organ development and the source and demand of nutritional at different stages in post-embryonic （water temperature 3-14℃） of Hucho taimen were discussed. The results showed that the membrane of H. taimen fertilized ovum was ruptured in 30 d, the prototype of U-type stomach was formed, the mouth could open and close freely, and nutrition was supplied from its yolk sac. The membrane ruptured after 8 d, teeth formed, and anus communicated with outsiders. The oropharyngeal cavity, esophagus, U-type stomach, intestine, and anus initially formed in the digestive tube, which nutrition was supplied from the huge yolk sac. The membrane ruptured after 16 d, pancreas and pyloric caeca appeared, larvae could intake and digest exogenous food, fish mixed nutrition, which was from yolk sac and outsiders, mainly depended on endogenous. The membrane ruptured after 24 d, the fish began floating and intaking actively, the fish mixed nutrition which mainly depended on exogenous. The membrane ruptured after 30 d, the yolk sac was completely absorbed, the function and structure of each digestive organs developed consummately, fish was from mixed nutrition into the stage of exogenous nutrition, the nutritional need of juveniles was below 10% fat, level of the optimal protein was 50%.展开更多
Objective The putative coronatean Punctatus flourished at the beginning of the Cambrian explosion, and is significant in the exploration of the origin and evolution of early life. Liu Yunhuan established a new specie...Objective The putative coronatean Punctatus flourished at the beginning of the Cambrian explosion, and is significant in the exploration of the origin and evolution of early life. Liu Yunhuan established a new species： Punctatus triangulicostalis Liu, 2006. Two questions remain： how was the special body plan of P. triangulicostalis formed？ How does P. triangulicostalis transform from embryo to the long cylindrical mature individual？ Although the study of Steiner et al. in 2004 involved the above questions, they did not explain them clearly due to the lack of fossil materials at that time. This article aims to consider the above questions based on new information from several rare specimens.展开更多
基金supported by the Tackle Key Problems in National Science and Technology(2006BAD03B08-01)the Heilongjiang Emphasis Technology,China(C2008-35)the Special Talents in Harbin,China(2009RFXYN044)
文摘With the technology of morphology, histology and nutrition, the characteristics of organ development and the source and demand of nutritional at different stages in post-embryonic （water temperature 3-14℃） of Hucho taimen were discussed. The results showed that the membrane of H. taimen fertilized ovum was ruptured in 30 d, the prototype of U-type stomach was formed, the mouth could open and close freely, and nutrition was supplied from its yolk sac. The membrane ruptured after 8 d, teeth formed, and anus communicated with outsiders. The oropharyngeal cavity, esophagus, U-type stomach, intestine, and anus initially formed in the digestive tube, which nutrition was supplied from the huge yolk sac. The membrane ruptured after 16 d, pancreas and pyloric caeca appeared, larvae could intake and digest exogenous food, fish mixed nutrition, which was from yolk sac and outsiders, mainly depended on endogenous. The membrane ruptured after 24 d, the fish began floating and intaking actively, the fish mixed nutrition which mainly depended on exogenous. The membrane ruptured after 30 d, the yolk sac was completely absorbed, the function and structure of each digestive organs developed consummately, fish was from mixed nutrition into the stage of exogenous nutrition, the nutritional need of juveniles was below 10% fat, level of the optimal protein was 50%.
基金supported by the National Natural Science Foundation of China (grant No.41572009)the State Key Laboratory of Palaeobiology and Stratigraphy (grant No.173121)the College Students’ Training Program of Chang’an University (201610710047, 201710710062, 201710710063, 201710710240)
文摘Objective The putative coronatean Punctatus flourished at the beginning of the Cambrian explosion, and is significant in the exploration of the origin and evolution of early life. Liu Yunhuan established a new species： Punctatus triangulicostalis Liu, 2006. Two questions remain： how was the special body plan of P. triangulicostalis formed？ How does P. triangulicostalis transform from embryo to the long cylindrical mature individual？ Although the study of Steiner et al. in 2004 involved the above questions, they did not explain them clearly due to the lack of fossil materials at that time. This article aims to consider the above questions based on new information from several rare specimens.
