摘要:

The feeding biology of the fish species in Plover Cove Reservoir, Hong Kong has been investigated with special reference toSarotherodon mossambicus(Peters). The food spectra of various fish species were analysed and compared and the results indicated thatS. mossambicusplayed an important role in the ecology of this reservoir since all major food sources were exploited.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04093.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Gyrometra kunduchin.sp. from the body cavity ofPlectorhinchus pictusfrom the Indian Ocean, off the coast of Tanzania is described and figured. The new species is differentiated fromG. albotaenia, the only species of the genus, by the absence of an apical pit, the extent of testes and vitellaria and measurements of the various organs.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04094.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Sixteen parasite species including one monogenean, two digeneans, five cestodes, six nematodes. one acanthocephalan, and one copepod were collected from 257 fish of 13 species examined from 32 lake and nine stream sites in the mountain National Parks of British Columbia and Alberta. The following parasites are reported from Alberta for the first time:Bunodera luciopercae(Müller, 1776),Eubothrium rugosumBatsch 1786,Proteocephalus parallacticusMacLulich, 1943,Rhabdochona cascadillaWigdor, 1918,Rhabdochona milleriChoquette, 1951,Contracaecum brachyurum(Ward&Magath, 1917),Bulbodacnitis truttae(Fabricius, 1794),Neochinorhynchus rutili(Mueller, 1780), andErgasilus nerkaeRoberts 1963.Tetraonchus variabilisMizelle&Webb, 1953 andRhabdochona milleriChoquette, 1951 are reported from British Columbia for the first time

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04095.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

The results of a 12 month study ofTrypanosoma platessaeLebailly (1904), a haemoflagellate parasitising the plaice,Pleuronectes platessaL., are presented. The morphological features of the trypanosome are described, with experimental investigations of the host specificity ofT, platessae. The flagellate occurred at low parasitaemias in wild plaice with a seasonal variation in the numbers of infected hosts, the percentage of parasitised fish reaching a maximum of 20 % in March and declining in the summer months.Attempts to establishT. platessaein the laboratory, by means of passage of infected blood, gave inconsistent results. Elevated levels of β‐globulins were detected in the sera ofT. platessaeinfected plaice, and it is suggested that this may be associated with antibody secretion to the parasi

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04096.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

WhenF. heteroclitusembryos were exposed to inorganic mercury at concentrations of 0.03 or 0.1 mg/1 at the early blastula stage, the percentage of successful axis formation was reduced and a significant proportion of embryos developed cyclopia or intermediate conditions leading to cyclopia. Treatment at the late blastula stage reduced the severity of the defects. Embryos which developed in lead at concentrations of 1 and 10 mg/1 were normal in appearance until hatching, at which time they exhibited lordosis or were unable to uncurl from the position they had while still inside the chorion. No significant effects of cadmium at concentrations up to 10 mg/1 were noted.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04097.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Adult perch,Perca fluviatilisL., were sampled at 3‐hourly intervals throughout 24‐h periods from June‐September 1971, and in June and August 1972. The wet weight of each major food component from the stomachs was expressed in parts per 10 000 of the fresh weight of the fish. From samples at capture, and others taken from caged fish at known time‐intervals after capture, the rate of stomach evacuation was estimated. Food consumption between netting times was calculated as the increment between successive initial values of stomach contents, plus the amount evacuated in the interval. As the evacuation rate of caged fish was slower than that of free fish the estimates of food turnover are minimal ones. The perch were consuming 6.5 % of their wet body weight per day in June, and this ration had decreased to 3.2% by Se

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1977.tb04098.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY