摘要:

This paper is a review of most of the research work on fish that has been carried out by the Freshwater Biological Association, and includes not only what has been done at Windermere, but also some past work carried out elsewhere. However, current work at the River Laboratory, which is now a separate establishment, has been excluded.The history of the Association i s traced from its formation in 1929 and its first laboratory at Wray Castle, to its present quarters at the Ferry House. Thc pre‐war work of Allen on trout, perch and salmon is described and an account is given of the war time research and fishery for eels and perch, and of how this has led to the experimental removal of perch and pike from Windermere on a large scale. The physiological research, and work on trout fry, on char and other species, as well as many subsidiary investigations, are mentioned. As far as possible brief summaries of the main results are given for most of the 99 papers mentioiic

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03262.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The stocks of powanCoregonus lavaretus(L.) in Loch Lomond (Scotland) were affected by an acute no‐ulcerative inflammatory lesion in the centre of the head, at the same time as ulcerative dermal necrosis (U.D.N.) became apparent in salmon in the Loch. The numbers of powan were very great at the time, and fish were of poor quality and frequently fungus‐infected. No pathogen was isolated from the lesions which rarely contained fungus, and were histologically very different from the lesions of U.D.N. in salmon. Its disappearance by the following year, coincided with a marked improvement in quality of the f

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03263.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

The lipids of five mesopelagic species of myctophid, two mesopelagic species of stomia‐toid, and one epipelagic species of Macrorhamphosidae from the eastern‐North Atlantic have been examined by thin‐layer chromatography and their fatty acid compositions have been determined by gas‐liquid chromat

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03264.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

A disease of young perch in Windermere was investigated. In contrast to the case of U.D.N. infections of salmon and trout, a variety of fungi were obtained from the diseased fish. These reflected the spora present in the water at the same time to a large extent. An exception wasSaprolegnia ferax, which did not grow on the fish and indicated that some degree of host specificity was involved. TheAchylaisolates, both from the fish and from the water, were found to be heterothallic and male in reaction.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03265.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

For three years the population size, rates of growth, standing stock, production and yield of all year classes of salmon and trout within three sections of a stream in Scotland were studied. Total salmon production as fresh weight per m2was 6.5 g in 1966, 10.6 g in 1967 and 11.1 g in 1968, and total trout production was 10.3g in 1966, 12.3 g in 1967 and 7.7g in 1968. Fish of 0+ and 1+ year old provided usually more than 90% of the total annual salmon production and 80 % of the annual trout production. Yield of salmon smolts (about 9 cm or longer after 2 years growth) per m2was 0.10 in 1966, 0.22 in 1967 and 0.15 in 1968. The smolt yield by weight was 29 % of the production of the 1966 year class of salmon and 16% of the 1967 year class. Numbers of trout of 9 cm or longer produced in the same time were higher and their weight was 60% of the total production of the 1966 year class and 32% of the 1967 year class.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03266.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Some aspects of the biology of the schellyCoregonus lavaretus(L.) were investigated by examining 188 that had passed down an aqueduct from Haweswater and 437 that were caught in gill nets set in Ullswater.In both lakes the main breeding season is from mid January to mid February, and in Ullswater spawning takes place in shallow water [less than 7.6 m (25 feet)] on a sandy bottom with stones and weed, at the entrance to a bay. The males in Haweswater first spawn when 3 years old and in Ullswater when 2; and the females first spawn in Haweswater when 4 years old, and in Ullswater when 3.Scales were kept from every fish and were found suitable for age determination. Some Haweswater schelly live for 9 years, but from Ullswater the oldest was 8. The rate of growth of male Haweswater schelly was very well described by the equation:(wherelt(=the length at time t) but the curve had to be transposed a further year to describe adequately the Ullswater male schelly growth. It is clear that the rates of growth are similar in the two lakes after the first year, during which it is much faster in Ullswater.A study of the length‐weight relation showed that the weight is proportional to the length cubed, and no difference in condition was found between males and females.The schelly egg was found to be slightly sticky, spherical and 2.98 mm in diameter. Some fertilized eggs were kept at various constant temperatures. At 4°C and 6°C the death rate was low, but was higher at 8°C and total mortality occured at 10°C. This low upper lethal temperature probably restricts the spawning season to mid‐winter and also limits the species' geographical range, as has also been suggested for the charSalvelitms alpinus(L.) whose eggs have similar temperature requirements.Some eggs were reared to adults, and these provided corroboration of the validity of the scales for age determination. Two other points mentioned in this paper were the occasional winter strandings of schelly, and the incidence of a supernumerary pel

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03267.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Tagged pikeEsox luciusL. in a drainable pond were fished by hook and line, using either a spinner or a small live fish as bait. Catch per unit effort could be used as a measure for catchability because all captured pike were immediately returned to the pond and mortality was low.Catchability to spinner fishing decreased to very low levels after about half of the population had been caught in this way. Catchability to live bait fishing remained unaffected both by intensive spinner and live bait fishing.It was difficult to capture pike more than once by spinning. In live bait fishing, on the other hand, the number of recaptures closely matched the number expected if catchability remains unaffected by earlier capture.The advantages are discussed of the use of artificial baits over live baits in hook and line fishing for pike.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03268.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Diel changes in the stomach contents of 0+, 1 + and 2+ or older trout were compared with diel changes in invertebrate drift. Peaks in mean numbers and biomass of invertebrates per fish stomach occurred in the midday (10.00 to 14.00 h) and evening (18.00 to 22.00 h) samples. The major peak was usually in the evening sample, but the major peak in biomass was in the midday sample for 2+ fish. There was a good correlation between diel changes of benthic invertebrates in the diet and drift, with the major peak in the evening. A similar relationship did not always exist for emerging and terrestrial invertebrates. Known non‐drifting benthic invertebrates (e.g. large caddis larvae) were excluded from the comparisons, and were only taken by 2+ or older trout in which they contributed a large biomass to the day foo

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03269.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Investigations of the erythrocyte count, haemoglobin content andMindex of 7 fish species were performed under equivalent environmental conditions in the same period of the year. The species were: bigheadHypophthalmichthys nobilis(Richardson), carpCyprinus carpioL., silver carpHypophthalmichthys molitrix(Val.), grass carpCtenopharyngodon idella(Val.), sheat‐fishSilurus glanis L., pikeEsox IndusL., pike‐perchLucioperca lucioperca(L.). Bighead and carp are carnivorous and omnivorous, silver carp and grass carp are herbivorous and sheat‐fish, pike and pike‐perch are predatory. Significant differences were demonstrable betweenMvalues of fish living on different type of food, where theMindex is:It is concluded thatMindex values are useful as one parameter differentiating between fish with distinctly different food

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03270.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Gonadal developnient has been studied throughout the larval period ofLumpetru fluviatitisand comparisons have been made with conditions in the larvae of the closely relatcd non‐parasitic species, L.planeri. The two forms differ in the time of onset or mitotic division in germ cells and in the period when oogenesis is initiated. These phases begin in L.pluneriwhen the ammocoetes are one year old and inL. fluviatilisat the end of the second year. The course of sex differentiation appears to be sinlilar in both forms. While in the early stages, the oocytes ofL. planeriare larger than those of L.fluviatilis.at comparable ages, by the end of the third year they are sinlifar in size in both spccics. It is suggested that in L.planeri, during the extension of the larval period, gonad growth is retarded and during this phase the ammocoete accumulates body reserves which are used to meet the metabolic requirements of the rapidly developing gonads after metamorphosis. The differences observed in early gonadogenesis are believed to account for the reduced fecundity of the L.planeriammococtc and their adaptive significance is discusse

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1970.tb03271.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY