To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divid...To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divided into seven portions from proximal to distal： the enlarged area after oesophagus, cardia, fundus, pylorus, and anterior, middle, and posterior intestine. Immunohistochemical method using the strept avidin-biotin-complex （SABC） was employed. All antisera between seven portions of the channel catfish were compared statistically using statistical package for the social science （SPSS）. Five types of DNES ceils were determined： neuropeptide Y-immunoreactive （NPY-IR） cells were demonstrated in both anterior and middle intestine; serotonin （5-HT） immunoreactive cells were detected throughout the whole gastrointestinal tract; vasoactive intestinal peptide （VIP） positive cells were at the highest frequency in pylorus; glucagon-immunoreactive （GLU-IR） cells were moderate in number in the fundus and anterior, middle intestine, and no immunoreactivity was determined in the other portions; somatostatin （SOM） positive cells were more abundant in the anterior and middle intestine. The regional distribution and relative frequency of immunoreactive cells in the channel catfish, Ictalurus punctatus, are essentially similar to those of other fish. However, some characteristics are observed in this species, which further proved that the diversity of the physiological function of DNES cells was based on their morphology.展开更多
Three ponds with the areas of 800, 1 000 and 1 000 m2 were settled in Yambajan aquaculture base for rearing test of Ictalurus punctatus in plateau zone. The results showed that as 30 000 fries were released, 19 830 fi...Three ponds with the areas of 800, 1 000 and 1 000 m2 were settled in Yambajan aquaculture base for rearing test of Ictalurus punctatus in plateau zone. The results showed that as 30 000 fries were released, 19 830 fingerlings of 1. punctatus were obtained after 270 d rearing, with the average body length of 21.2 cm, the average body weight of 216.5 g, the survival rate of 66.1%, and the fingerling harvest of 4 293.2 kg. Thus, it is effective and feasible to rear I. punctatus with residual heat resources of power plants in cold plateau zone.展开更多
The channel catfish Ictalurus punctatus was first introduced from the United States to the Krasnodar region of Russia 1972-1979, and it was introduced into Georgia during 1976-1978. Ecological and economic studies of ...The channel catfish Ictalurus punctatus was first introduced from the United States to the Krasnodar region of Russia 1972-1979, and it was introduced into Georgia during 1976-1978. Ecological and economic studies of channel catfish were initiated along with the acclimatization and naturalization of this new species. Channel catfish were initially reproduced and reared in the Japan aquaculture fish farm ponds. Offspring from these ponds were used to stock other ponds, industrial fish farms and natural water bodies （lakes） where natural populations were formed. The climatic conditions of Georgia are close to the natural habitat of channel catfish. The number of days with water temperature higher than 20 ℃ is about 120-140, and the accumulated heat reaches up to 2,400-2,792℃. The purpose of targeted acclimatization was for the development of aquaculture-commercial production and recreational fisheries. During the process the method of staged radial acclimatization was applied, which initially included breeding and growing of fishes in aquaculture farms. Offspring produced in hatchery were then introduced into new fish farms and water bodies to develop populations. The water temperature 22-26 ℃ in the ponds are suboptimal for breeding the channel catfish, nevertheless the productivity in ponds is 3 tons/ha, in cages 50-60 kg/m3, and in pools with thermo-regulation of water 100-150 kg/m3. In some trial water bodies, the natural breeding of channel catfishes were observed, proving the existence of independent （self-breeding） populations. This process however was significantly hampered by severe economical hardship occurred in the country during 1990＇s joined with the uncontrolled fishery. The current economical growth in the country also influences the aquaculture sector and many private fish farmers are interested in commercial breeding of channel catfish, scarce population of which still exists in the former experimental water bodies. The bio-technology of rearing the channel catfish, elaborated duri展开更多
基金supported by the Special Founda-tion for Young Leaders Fellowship in the Sichuan Agri-cultural University, China (45078925-5).
文摘To detect distribution and relative frequency of diffuse neuroendocrine system （DNES） cells in the gastrointestinal tract of channel catfish （lctalurus punctatus）, the intestinal tract of channel catfish was divided into seven portions from proximal to distal： the enlarged area after oesophagus, cardia, fundus, pylorus, and anterior, middle, and posterior intestine. Immunohistochemical method using the strept avidin-biotin-complex （SABC） was employed. All antisera between seven portions of the channel catfish were compared statistically using statistical package for the social science （SPSS）. Five types of DNES ceils were determined： neuropeptide Y-immunoreactive （NPY-IR） cells were demonstrated in both anterior and middle intestine; serotonin （5-HT） immunoreactive cells were detected throughout the whole gastrointestinal tract; vasoactive intestinal peptide （VIP） positive cells were at the highest frequency in pylorus; glucagon-immunoreactive （GLU-IR） cells were moderate in number in the fundus and anterior, middle intestine, and no immunoreactivity was determined in the other portions; somatostatin （SOM） positive cells were more abundant in the anterior and middle intestine. The regional distribution and relative frequency of immunoreactive cells in the channel catfish, Ictalurus punctatus, are essentially similar to those of other fish. However, some characteristics are observed in this species, which further proved that the diversity of the physiological function of DNES cells was based on their morphology.
文摘Three ponds with the areas of 800, 1 000 and 1 000 m2 were settled in Yambajan aquaculture base for rearing test of Ictalurus punctatus in plateau zone. The results showed that as 30 000 fries were released, 19 830 fingerlings of 1. punctatus were obtained after 270 d rearing, with the average body length of 21.2 cm, the average body weight of 216.5 g, the survival rate of 66.1%, and the fingerling harvest of 4 293.2 kg. Thus, it is effective and feasible to rear I. punctatus with residual heat resources of power plants in cold plateau zone.
文摘The channel catfish Ictalurus punctatus was first introduced from the United States to the Krasnodar region of Russia 1972-1979, and it was introduced into Georgia during 1976-1978. Ecological and economic studies of channel catfish were initiated along with the acclimatization and naturalization of this new species. Channel catfish were initially reproduced and reared in the Japan aquaculture fish farm ponds. Offspring from these ponds were used to stock other ponds, industrial fish farms and natural water bodies （lakes） where natural populations were formed. The climatic conditions of Georgia are close to the natural habitat of channel catfish. The number of days with water temperature higher than 20 ℃ is about 120-140, and the accumulated heat reaches up to 2,400-2,792℃. The purpose of targeted acclimatization was for the development of aquaculture-commercial production and recreational fisheries. During the process the method of staged radial acclimatization was applied, which initially included breeding and growing of fishes in aquaculture farms. Offspring produced in hatchery were then introduced into new fish farms and water bodies to develop populations. The water temperature 22-26 ℃ in the ponds are suboptimal for breeding the channel catfish, nevertheless the productivity in ponds is 3 tons/ha, in cages 50-60 kg/m3, and in pools with thermo-regulation of water 100-150 kg/m3. In some trial water bodies, the natural breeding of channel catfishes were observed, proving the existence of independent （self-breeding） populations. This process however was significantly hampered by severe economical hardship occurred in the country during 1990＇s joined with the uncontrolled fishery. The current economical growth in the country also influences the aquaculture sector and many private fish farmers are interested in commercial breeding of channel catfish, scarce population of which still exists in the former experimental water bodies. The bio-technology of rearing the channel catfish, elaborated duri
