摘要:

Blood serum components in channel catfish (Ictalurus punctatus) were compared between raceway (with low dissolved oxygen) and pond populations. Normal limits were defined for the pond populations, for each of 18 variables, as ± two standard deviations. Carbon dioxide, blood urea nitrogen, total protein, uric acid, creatinine, sodium, and total bilirubin were all lower in fish raised in raceways. Carbon dioxide and sodium had the greatest reductions; all reductions were statistically significant.Alkaline phosphatase, inorganic phosphorus, calcium, cholesterol, and glucose values were higher in raceway fish, but only alkaline phosphatase and glucose were significantly higher

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04133.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The annual fish yield of 73 000 tonnes (22.5 kg/ha) from Lake Tanganyika consists primarily of two planktivorous clupeidsStolothrissa tanganicae(Stdr.) andLimnothrissa miodon(Blgr.) and their centropomid predators, threeLatesspecies (Nile perch) andLuciolates stappersii(Blgr.). At the north and south ends of the lake, theLatesspp. have been fished‐up by purse‐seines, and the clupeids and youngL. stappersiipredominate there. Estimates of pelagic fish biomass may employ (i) catch and fishing effort data (ii) abiotic variables (iii) echo‐sounding surveys (iv) tropho‐dynamic relati

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04134.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Gldfish,Carassius auratusof varying sizes were conditioned in continuous light or darkness f or 10, 20 and 30 days and the incorporation of3H‐thymidine into the gonads was investigated to attempt to develop a bioassay for fish gonadotropins.The 24‐hour gonadal3H‐thymidine of 10‐day conditioned fish was significantly less at the dose level of 0.5 μCi3H‐thymidine/fish compared to 1.0, 2.0 and 3.0 μCi/fish which gave gonadal activities not significantly different from each other. Thus, for all subsequent work the dose of 1.0 μCi/fish was used.Photoperiod of continuous light or darkness had little effect on fish weighing less than 11 g but in fish 11‐15 g conditioned for 20 days in darkness and fish greater than 16 g conditioned for 10 days in darkness, depression in gonadal3H‐thymidine incorporation occurred. In fish 11‐15 g, prolonged conditioning for 30 days in darkness induced more gonadal activity than was observed at 20 days.The effect of injection ofChanna striatuspituitary extract at doses of 1 mg/10 g body weight and 5 mg/10 g body weight induced a significant increase in3H‐thymidine incorporation in the gonads over saline injected controls. The results suggest the potential of using photoperiod as a means of inducing regression of gonads of suitable fish in a bioas

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04135.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The histochemical profiles of the major myotomal muscle fibre types and the proportion of red muscle in the myotome of a number of teleost types has been investigated in relation to their observed swimming behaviour. A direct relationship exists between the proportion of red muscle present and the ability to sustain swimming. The red muscle fibres were found to be metabolically adapted for this role, whilst the white muscle fibres were better adapted for more vigorous activity. The possible roles of the pink and other fibre types are discussed. The histochemical investigation revealed no differences between the teleost types except that the deep white muscle of a pelagic species may have a higher aerobic capacity than that of other species.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04136.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

After cod (Gadus morhuaL.) had been exercised in a channel, the intensity of pigmentation of the dark muscle was shown to be greater than in unexercised controls. A well‐marked seasonal cycle in pigmentation occurs in cod caught near Aberdeen with a summer maximum suggesting maximal feeding activity. The possibility of using the observation to identify stocks of fish is considere

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04137.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

A method is described for the assessment of fecundity in mormyrid fish. In all species examined a tri‐modal egg size distribution was found in the mature pre‐spawning ovary. These modes represented one oocyte and two ova components. The significance of the presence of two sizes of ovum is discussed in relation to breeding periodicity inHippopotamyrus pictus. Size and age at first maturity are estimated for this species. The probable effects of the formation of the lake on the breeding behaviour of mormyrids is discus

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04138.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The food and cellulase activity of five cyprinid and one salmonid species were examined. All Cyprinidae species showed cellulase activity. No activity was found in pelagicCoregonus albula(Salmonidae). Cellulase activity showed a positive correlation with the amount of highly processed plant detritus in the gut. No correlation was found between the activity level and the amount of fresh fragments of macrophytes and filamentous algae.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04139.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The data available in the literature concerning fish thrombocytes, lymphocytes, monocytes, macrophages and granulocytes is discussed and the dearth of reliable information concerning the functional identity of most fish leucocytes is underlined. The methods of applying nomenclatures to fish leucocytes encountered in the literature is discussed in some detail and found to be unsatisfactory. An attempt is made to simplify the confused and conflicting reports by applying the concepts which have recently arisen in the field of mammalian immunology. Nomenclatures are assigned to cells on a functional and morphological basis where sufficient data exists.Thrombocytes are responsible for clot formation and are considered to be distinct, separate and unrelated to lymphocytes. Lymphocytes are recognised as immuno‐competent cells though as yet little information exists on their role in immune mechanisms. Recent work is furnishing interesting results in this direction, especially in the origin of lymphocyte populations and their co‐operative responses in immunity. Previous references to monocytes and macrophages in fish are confused and the literature is discussed in the light of the new classification of the Mononuclear Phagocyte System.Very few experimental data exist concerning granulocytic leucocytes in fish, indeed the presence of such cells with granulocytic functions still requires proof. Cells with morphological similarity to mammalian granulocytes do exist in fish but information essential for an understanding of their role in defence mechanisms is lacking. The state of the literature concerning the eosinophil, basophil and mast cell in fish is so confused that an entirely new approach to a study of these cells is warranted. It is hoped that this review will supply guidelines for future resea

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04140.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Electrophoretic variation of Atlantic salmon NADP‐isocitrate dehydrogenase in liver extracts of material from Ireland is interpreted in terms of two loci,IDH‐AandIDH‐B, coding for cytoplasmically‐located isozymes. TheIDH‐Alocus is polymorphic withqIDH‐A1=0.18 andqIDH‐A2=0.82. This polymorphism is of potential value for investigating the population genetics of the two races of Atlantic salmon in Ireland. An additional, monomorphic band which appears in heart extracts may be a mitochondrial enzyme coded by

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04141.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Uptake, metabolism and excretion of radio‐labelled N‐tritylmorpholine (Frescon) were studied in the tropical food fishSarotherodon mossambicus(Peters). After 55 h exposure to sub‐lethal solutions, concentration factors in whole fish were as high as 1300 (up to 40 mg/kg), at least 80 % of the absorbed activity being unchanged Frescon. Approximately 40 % of this activity was found in bone, 16% in muscle, 16% in gut and 10% in gill. The bile was found to be a route of Frescon excretion, and recovering fish excreted 50% of the absorbed activity in 55 h. The applicability of these results to the field situation is disc

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04142.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY