摘要:

The concentration of protein in the sera of rainbow trout,Salmo gairdneri, brown troutS. truttaand Atlantic salmonS. salarhas been measured by six standard techniques viz refractometry, copper sulphate specific gravity, automated and manual biuret, optical density and Lowryet al.phenol reagent and the results compared. Good correlation was obtained in most cases and interconversion formulae are given between each method in the three salmonid species. The concentrations obtained with the refractometer and optical density methods were approximately one and a half times those obtained with the others.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03691.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Data for two sampling years (1969/70 and 1970/71) is presented to illustrate the changing composition, density and biomass of the macroinvertebrate fauna in a South Lancashire lake. Six faunal groupings are recognised for a non‐parametric analysis of the data and significance levels are given for the between‐station and between‐year differences recorded. The mean density of macroinvertebrates (1.2 mm mesh sieve) estimated for the lake as a whole increased by 28.5% in the second year (2519 m−2‐3237 m−2) whereas the estimated mean biomass in g m−2increased by 86% wet weight (8.61−16.01) and 196% dry weight (1.74−5.15). Molluscs contributed substantially to the increased standing crop which was accompanied by increased development of macrophytes.A comparative study of the diets of roach in two size groups in winter and summer is described. The variety of food items consumed was found to be greater than in a preliminary study in May 1969 and, for the roach sampled, the average quantity of food consumed per fish increased after the 1969/70 winter. The possible relationships between invertebrate standing crop, roach diet and previously reported changes in the growth of the roach are discussed and an explanation is offered concerning the sequence of biological changes obs

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03692.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Enteromorpha compressa(L.) Greville andE. clathrata(J. Agardh), widely distributed green algae in Arabian Gulf, were observed growing onAcanthopagrus cuvieri(Day). Abscessed areas on the operculum provided suitable sites for attachment of both species of algae; broken spine tips were preferred byE. compressa. This study showed that these algae preferred hard substrata, with no scales for attachment.E. compressaappeared earlier and grew faster. The condition of the fish was normal.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03693.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Biochemical genetics of a Atherinid species,Atherina boyeriwere undertaken to determine variability. Among the 17 loci studied, 7 were polymorphic, of which three were retained for a more detailed comparison of populations inhabiting the French Mediterranean coastal lagoons. A microsporidiosis is present in these fishes and is limited to certain lagoons. Comparison of allelic frequencies at the polymorphic loci between fish populations of infected and healthy lagoons yielded no significant differences. Several hypotheses are discussed and attempt to agree parasite distribution with genetical results.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03694.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The anatomy and morphology of the digestive tract of the eel was examined using light and scanning electron microscopy. The oeosphagus showed complex longitudinal folding; stratified epithelium, columnar epithelium and goblet cells striated muscle fibres formed the thick muscular coat. The pneumatic duct entered the oesophagus anterior to the oesophagastric junction. The Y shaped stomach showed large well developed folds which decreased in size and number towards the pyloric sphincter. Columnar epithelium and gastric gland cells were present, the latter being absent from the pyloric region.The intestine had a heavily thickened anterior region, signs of convulation were noted prior to the ileorectal valve. Intestinal folding showed a complex reticulate pattern with columnar epithelium and goblet cells present. The mucopolysaccharides were studied in the goblet and columnar cells throughout the regions of the gut. Lymphocytes and eosinophilic type cells were found in the connective tissue of the mucosa throughout the gut. The pancreas was a compact organ with few Islets of Langerhans, beta cells were peripherally situated and alpha cells centrally. The unilobular liver acted as a storage organ for oil and glycogen.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03695.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Grass carp acclimated to 3, 5, 7, and 9% salinities were tested for salinity tolerance. The upper tolerance limit (LS50) for 3 and 5%, and 7% acclimated fish were 14.2 and 14.0%, respectively. Fish acclimated to 9% had a 50% mortality at an estimated salinity of 16.0%, for 24 h exposure. Weight losses for the 3 and 5% acclimated fish were significantly lower than for those acclimated to 9%.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03696.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Osmotic fragilities and erythrocyte sedimentation rates (ESR) were measured in healthy, diseased, treated and recovered trout,Salmo gairdneri. Bacterial infection withAeromonasandStreptococcusresulted in more fragile erythrocytes and raised ESR values. Treatment with antibacterial agents improved the values of both parameters. Possible reasons for such changes are discussed. Caution in the use of apparently healthy fish for the unqualified interpretation of haematological results is expressed.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03697.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Brown trout produced high molecular weight, thermostable, dithiothreitol sensitive, non‐precipitating, complement‐fixing antibodies and agglutinins to lipopolysaccharides after intramuscular injection with adjuvant. Antibodies were first detected on Day 14 and reached maximum titres after 56 to 63 days when a single injection was given. When either a second or a third injection was administered maximum titres occurred 34 to 40 days after the injection. After each injection the titres increased significantly, and the protein concentration of the sera was significantly decreased. In cellulose acetate electrophoresis experiments those bands which migrated in the β‐ to γ‐globulin regions were increased.Antibody‐secreting and antigen‐binding cells were detected on Days 8 and 4 respectively and maxima were reached between Day 16 and Day 18. The number of cells per 106lymphoid cells was higher in the spleen than

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03698.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The diets of five gadoid species in the northern North Sea are described: the cod,Gadus morhua(L.); haddock,Melanogrammus aeglefinus(L.); whiting,Merlangius merlangus(L.); saithe,Pollachius virens(L.); and the Norway pout,Trisopterus esmarkii(L.). The diet of each species was shown to be a gradual progression to different prey species as the predators increased in length. There were differences in the food taken by each species with respect to numbers, species and size. These differences in diet suggest that the degree of competition between pelagic O‐group gadoids is not grea

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1980.tb03699.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY