摘要:

Hatchery reared Atlantic salmon (Salmo salarL.) parr were tagged with the standard I.C.E.S./I.C.N.A.F. salmon tag at water temperatures of 15°C and 6°C. They were then subjected to swimming trials in a tunnel respirometer. Following this treatment the 15°C fish developed necrotic infarcts around the tag insertions. Provided they did not become infected these lesions healed, but if the fish were retested 9 days later, the wound enlarged, became extremely inflamed, and the fish died soon after. This effect was not seen in 6°C f

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03951.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Infections of brown troutSalmo truttaL. by larvae of the nematodeEustrongylidessp. were studied over a period of two years in Fernworthy Reservoir, Devon. The parasite, here as elsewhere in Britain, is acquired only in the lake itself and not in the streams feeding it. Both native and introduced brown trout were infected but not rainbow trout which did not survive sufficiently long in the reservoir. The parasite showed a preference for female fish and for fish over 20 cm in length. Since these latter were approaching the end of their natural life span in the lake, there was insufficient time for the parasites to accumulate in older fish. No seasonal changes in infection levels or size composition of the parasite population were recorded. The larvae occurred in capsules, the majority of which were attached to the stomach wall. No local pathological effects associated with the capsules were observed and infested fish were of similar length, weight and condition to uninfected ones. The absence of harmful effects upon the trout in Fernworthy Reservoir is compared and contrasted with the effects of the parasite in other localities. It is concluded that althoughEustrongylidescan occasionally cause damage to some species of fish, there is no conclusive evidence that it does so to trout. but its unsightly appearance and harmful effects on birds renders it an undesirable parasite in any fishery.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03952.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

The meristic features ofPellonula afzeliusiandSierrathrissa leonensisare compared to remove the confusion that has arisen over the identity of two clupeid species in West African freshwaters.The discovery of a breeding population ofS. leonensisin Kainji Lake confirms that it is correct to regardS. leonensisas a separate species and not the young of eitherPellonulaorCynothrissaas was claimed by Roberts (1972).

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03953.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

In the years 1972 to 1974, inclusive, a total of 50 salmon originally tagged as smolts in British rivers were recaptured in Irish waters. Although it is not possible to give precise reasons for these changes, some factors can be largely eliminated. The results do, however, indicate that salmon and grilse derived from British rivers occur in Irish inshore waters to a greater extent than was generally accepted.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03954.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

This is a first confirmed report of vibriosis or ‘red‐pest’ from wild eel (Anguilla anguilla) stocks in Great Britain. It is postulated that the epizootic was provoked by severe stress resulting from the abnormally high estuarine water temperatures and low freshwater flows present in affected rivers at the time. Bacteriological characteristics of the isolate, which was classified as aVibriosp., are desc

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03955.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Swimming activity of the obligatory air‐breathing fishOphiocephalus striatusreared in cylindrical aquaria on different rations (0–43.3 mg/g/day) increased from 58 m/day for the starving group to 439 m/day for the group fed a maximum ration. Swimming speed also increased from 2.4 cm/sec in the former group to 5.2 cm/sec in the latter group. Owing to sustained swimming activity and the consequent fatigue, the test individuals ‘hung’ to the surface for a definite interval. Duration of surface ‘hanging’ increased from 3.2 h/day to 15.8 h/day with decreasing ration. The group receiving 25.5 mg/g/day converted most efficiently (28%). The maintenance energy cost is equivalent to 10 mg/g/day and dry substance equivalent to 5 or 12 mg/g/day was expended on the sustained swimming activity by the fish receiving the optimum (25 mg/g/day) or the maximum (43 mg/g/

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03956.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

The histopathology of biliary hyperplasia and renal calcinosis, associated with infections of two parasites,Myxidium incurvatumandRhabdospora thelohani, is described in turbot,Scophthalmus maximus(L.), from Scottish marine fish farms and wild populations. Liver and kidney lesions were divided into four, and parasite infections into five grades of severity. A few of the fish examined were not parasitized, but every one showed some evidence of pathological change, even the apparently normal individuals from all populations. Although there is a positive association between the parasitic and pathological data, parasitism is not considered to be the principal cause of either the hepatic or renal lesion; the evidence suggests rather a secondary opportunist role for the parasites. The general severity of the condition in captive stocks suggests that the cause may lie in the fundamentals of present techniques of turbot husbandry, but no specific agent has been identified. A case is put forward for consideringRhabdosporato be a parasite rather than a specialized host cell.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03957.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Book reviewed in this article:THE LIVING OCEAN. by E. J. Ferguson‐wood.THE PATHOLOGY OF FISHES edited by W. E. Ribelin&G. Migak

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1976.tb03958.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY