摘要:

The ranges and mean values of haematocrit, red cell, white cell and differential cell counts, red/white cell ratio, red cell fragilities, haemoglobin levels and serum protein concentrations of adult pikeEsox luciusL. have been measured, and the serum electrophoretic patterns on cellulose acetate and polyacrylamide gel described and discussed. It is hoped that these blood values will provide normal standards for the pike since normal ranges are wide, and isolated measurements therefore of limited value.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03275.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The acute lethal toxicities to rainbow trout,Salmo gairdneriRichardson, of mixtures of copper and phenol, of copper, zinc and phenol, and of copper, zinc and nickel, over an exposure period of 48 h were determined. The concentrations selected for testing were such that each poison theoretically contributed equally to the toxicity of the mixture. It was found that the toxicities of these mixtures could be adequately predicted by summation of the fractional toxicities of the particular poisons which were present.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03276.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Records of burbotLota lota(L.) captures from the early nineteenth century to the present have been gathered and arranged watershed by watershed in chronological order. Most are from eastward‐flowing river systems from Durham southwards to the Great Ouse, but a few records from westward‐flowing systems are considered. In many areas the records imply a decline of burbot numbers and distribution during the present century, though burbot may never have been more than locally abundant. Local over‐fishing, pollution and habitat changes are considered the most likely causes of decline. Conservation measures seem desi

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03277.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The skin of the head of adult Atlantic salmonS. solarL. was examined by light and electron microscopy. The general structure resembled that of most other vertebrates, but in common with other fish, the melanocytes were restricted to the papillary layer of the dermis. The mucus secreting cells were shown to elaborate a series of separate membrane bound vesicles of secretion. The basement‐membrane was complex, with a system of primary, and secondary micro‐papillae showing close adherence to the bases of the epithelial cells, which were modified to form a thick, electron dense basal plasma membrane. No evidence to suggest a reason for the localization of the early lesions of ulcerative dermal necrosis to specific areas of the epithelium of the head was addu

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03278.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Laboratory tests were conducted to determine the tolerance of 2+ grass carp to an oceanic water. It was found that at a temperature of 20.1°C±0.4°C the maximum survival times of the fish in concentrations of seawater equivalent to 17.5 and 10.5 g/1 sodium chloride were 5 h and approximately 24 days respectively. The importance of these results lies in the consideration of the possibility of grass carp migrating through brackish or seawater from one river system to another. Such a migration would seem to be impossible through seawater but may be possible through brackish wat

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03279.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The metacercarial cyst of the heterophyid trematodeStellantchasmus falcatusin the striated muscles of the mulletMugil cephalusconsists of three layers. Histochemical studies have indicated that these layers are chemically distinct. The acellular inner layer is comprised of complex carbohydrate polyanions rich in acidic groups while the medial cellular layer is comprised of a neutral mucopolysaccharide including a moeity of carbohydrate poiyanions. These two layers are believed to be of parasite origin. The outer layer is cellular and is of host origin. It is the most chemically complex and is believed to include one or more of the following: mucopolysaccharides, glycolipids and phospholipids. In addition, the carbohydrate moeity associated with the mucopolysaccharides and/or glycolipids is in the form of sulphated carbohydrate polyanions with undissociated carboxyls as well as acidic groups.The presence of the parasite results in the necrotic degeneration of the host's myofibers situated in the proximity of the parasite. Large fat cells fill the spaces vacated by necrotic muscle cells and many blood cells occur along the periphery of the parasite.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03280.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Nine antiseptic compounds, at concentrations ranging from O.1 to 0.0001 %, were testedin vitrofor their ability to inhibit the growth ofSaprolegnia. This fungus was isolated from suspected UDN‐infected Atlantic salmon. Malachite green was the most effective antiseptic. Fungal growth was completely inhibited at all the concentrations teste

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03281.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Observations are made on the development and the presence of a Saccus Vasculosus inTilapia mossambicaand other cichlids.In those cichlids that do not possess a saccus vasculosus the development of this organ is apparently suppressed in a very early stage of life.A saccus vasculosus is present in all those American and Indian cichlids that were investigated, but this organ was not found in cichlids indigenous to the African continent.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03282.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The composition and nutritive value of different diets, namely the aquatic weeds—Hydrilla verticillata(L.f.) Presl.,Lemna gibbs(L.)Pistia stratiotes(L.), grasses—Guinea grassPanicum maximumJacq., Napier grassPennisetum purpureumSchum. and plants—sweet potato leavesIpomaea batatasL. and tapioca leavesManihot utilissimusPohl. were determined and compared. The diets contained 13.5 to 30.48% protein; 1.89 to 9.60% fat; 3.94 to 23.13% ash; 5.42 to 26.70% fibre and 24.87 to 46.27% carbohydrate. Most of the minerals determined in the aquatic weeds were higher than those in grasses and plants. The feeding ofHydrilla, Napier grass and tapioca leaves to grass carpCtenopharyngodon ideltus(V.) showed a different growth rate and the results obtained indicated the superiority ofHydrilladiet over Napier grass and tapioca l

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03283.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The study of the emerald shinerNotropis atherinoidesRafinesque was conducted in 1967 and 1968 in Lake Simcoe, a eutrophic inland lake with an area of 725 km2situated in the Province of Ontario, Canada. On the basis of meristic characters, the emerald shiner of Lake Simcoe conforms to the classical description of the species and is not distinct from the form inhabiting the Great Lakes. Annulus formation occurred in early June on age I fish but second and third annuli were not formed on older fish until late July through August.Young‐of‐the‐year emerald shiners reached a total length of 45 mm by October; age I were 81 mm and age II measured 92 mm by the same month. By September, age I female emerald shiners attained a size superiority of 5 mm over males of that age group and by the end of the third summer age II females exceeded age II males by 8 mm. Spawning occurred offshore in the latter part of July when surface water temperatures approximated 20°C. Of the three age groups, age II specimens were the most prevalent on the spawning grounds. Average absolute fecundity was 3410 eggs in fish of all age classes combined. Differences in water temperature seem to strongly influence the seasonal distribution pattern of the emerald shiner. The final temperature preferendum of the species, as determined in a vertical temperature gradient tank, was 25°C. The emerald shiner is extensively utilized as a bait fish by anglers and appears to be an important forage fish. The plasticity of the species to adapt to a variety of ecological conditions and the species potential for high production favour its introduction to waters requiring a good converter in the foo

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03284.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY