摘要:

The intestinal histology ofD. cepedianumwas examined by light microscopy. The results are discussed in relation to previous findings.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03501.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Environmental adaptive response of fishes to the nutritional deficiencies of two important vitamins of the B‐groupviz. cyanocobalamin and folacin has been investigated using growth, haematology and haemopoiesis as physiological indices. Extended studies lasting 105 days revealed a consistent decrease in growth or even loss of weight when cyanocobalamin and folacin were absent from the diet. The combined deficiency of these two vitamins had an additive rather than synergistic effect on growth. The feed conversion values of all the deficient groups were significantly low as compared to the control. Haematologically the occurrence of anaemia and leucocytosis were recorded in all the deficient groups, the former mainly of megaloblastic type. Differential WBC counts revealed that leucocytosis was mainly due to an increase in thrombocyte population and cosinophils. On the other hand, there was an relative decrease of other nongranulocytes and granulocytes. Erythro‐poietic investigations revealed a decreased proliferation rate of the reticuloendothelial cells and an increased number of young and mature reticulocytes and immature erythrocytes into the peripheral bl

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03502.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

In a laboratory stream channel consisting of two tributaries joining to form a ‘river’ it proved possible to establish three populations of minnows in separate home ranges. Minnows in the apparatus avoided water with low concentrations of dissolved oxygen but returned to the home range when aerated water was re‐established. Concentrations of 4, 8 and 10 mg 1−1of phenol did not cause avoidance behaviors, in fact the highest concentration killed some fish, but activity levels were severely depressed and shoaling behaviors was also a

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03503.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

To evaluate physiological stress resulting from environmental influences, a haematological study of a natural population of largemouth bass,Micropterus salmoides, was undertaken to establish a ‘normal’ blood profile. Several parameters including haemoglobin concentration, haematocrit, erythrocyte count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, plasma protein concentration and glucose levels were investigated. Haematocrit, haemoglobin, and total plasma protein were positively correlated with fish length. Haemoglobin and haematocrit were positively correlated with fish age while mean corpuscular haemoglobin, concentration was negatively correlated with fish age. Both haemoglobin and haematocrit values were related to erythrocyte cou

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03504.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Anaemia can be induced in Rainbow trout by removing 12 % of the blood volume by cardiac puncture. Recovery from such an anaemia has been monitored in both normal and splenectomized fish. After the bleeding there is a decrease in red cell numbers, haematocrit and blood haemoglobin concentration. Although recovery in normal trout was not complete within 27 days, which was the period of the observations, it was seen as a replenishing of red cell numbers, haematocrit and blood haemoglobin concentration. Mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC), both depressed by the bleeding, did not appear to recover during the experimental period.Splenectomy reduced erythropoietic intensity. After bleeding all the parameters studied were more depressed than those found in normal trout, and recovery was not noted. Blood haemoglobin and red cell numbers did not have the same post‐bleeding pattern as normal individuals; MCH and MCHC values remained markedly depressed.Splenic involvement was further demonstrated by bleeding trout for a second time from both normal and splenectomized groups. In contrast to the response of normal animals, there was a further deterioration of red cell numbers and blood haemoglobin concentration in splenectomized individual

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03505.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The survival of salmonSalmo salar, sea trout and brown troutSalmo truttaeggs in acid water in the range pH 3·5±7·0 was investigated over a period of three winters. The effects of fertilising the eggs in acid water at pH 4·0, 4·5 and 5·0, and dilution of the test media were also studied. There was considerable yearly variation in the numbers of eggs which hatched, but there were no marked differences between the three species in the tolerances of the eggs to acid water; pH 3·5 was lethal within 10 days to all the eggs, but at pH 4·5 and higher pH levels there was no obvious difference in hatching attributable to

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03506.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Hatchery reared rainbow and brown trout (length 20 cm) were released in March 1974 and April 1975 respectively into the Taff Bargoed, a small river in South Wales, polluted by coal wastes and containing a low resident population of brown trout. From subsequent electro‐fishing surveys and catch returns from anglers, extensive downstream movements occurred in both species. About 50% had either been caught or had moved out of the river, a distance of about 5 km, after two weeks and after two months only some 10 % remained. Within the fishing season it was estimated that 3 and 22% of brown and rainbow trout respectively were caugh

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03507.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

An anatomical study of the digestive tract of the channel catfish revealed that the oesophageal mucosa was longitudinally folded and that secondary folds were occasionally located on the primary longitudinal folds. The infoldings were more numerous near the stomach. The stratified squamous epithelium covering the folds was made up of a basal layer, large mucous cells and simple squamous cells on the surface. The epithelium on the side of the folds consisted primarily of mucous secreting cells. Taste buds were observed between mucous cells on the apical portion of the oesophageal folds and were more prevalent in the cranial part of the oesophagus. The remaining layers of the oesophagus were: a lamina propria‐submucosa, tunica muscularis and adventitia or serosa.The J‐shaped stomach had two regions: a large sac‐shaped region containing gastric glands and a smaller, nonglandular pyloric region. The large rugae of the stomach became gradually smaller near the pylorus. There was a well developed pyloric sphincter. The mucosa included a simple columnar epithelium, a lamina propria and adventitia or serosa.The intestine could be differentiated into a thick ascending segment, a descending segment, a thin convoluted segment and a thicker terminal segment, the rectum. Many mucosal folds containing branched villi characterized the ascending segment of the intestine. The descending and convoluted segments contained fewer folds with shorter and less‐branching villi and were smaller in diameter and thinner walled. Descending and convoluted segments were also mildly convoluted and accounted for 80% of the total length of the intestine. An intestinal valve with a sphincter marked the beginning of the rectum. There was an approximately four‐fold increase in the thickness of the tunica muscularis of the terminal segment of the

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03508.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The scanning electron microscope (SEM) has been used to study the morphology of the accessory air‐breathing organs of the catfishClarias batrachus. Although the gross morphology of the dendritic organs, the fan organs and the membrane lining the supra‐branchial chambers differ, the nature of the respiratory surfaces are similar. The gaseous exchange surfaces of all three organs consist of double rows of paired lamellae, a feature strongly indicative of their common origin from the gills. The surfaces of the epithelial cells from the respiratory organs were seen to have numerous small projections consisting of microvilli and short microridges. This is in contrast to the concentric whorls of micro‐ridges on the surface of cells from the interlamella regions of these o

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03509.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Metabolic effects of partial pancreatectomy (70%) after 1 month were studied in the Northern pike,Esox luciusL. Plasma protein and haematocrit levels were significantly reduced in the pancreatectomised fish when compared with sham‐operated controls. By contrast, however, blood glucose, plasma amino acid nitrogen and cholesterol levels remained unaltered.The tolerance to intra‐arterial glucose and amino acid loading was compared in pancreatectomised and control fish. Pancreatectomy resulted in a significantly impaired clearance of amino acids from the plasma whereas glucose tolerance was similar in both groups. Neither glucose nor ketones could be detected in the urine of pancreatectomised pike after 1 month. These data indicate that partial pancreatectomy does not cause the development of a diabetic state in this species over a 1 month per

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1979.tb03510.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY