摘要:

SummaryThe stocks of shrimpsParapenaeopsis styliferaandMetapenaeus dobsoniin the fishery of two areas of Kerala coast in India have been studied using length frequency data. The average annual stocks of the two species have been indicated. The present status of fishery shows a differential fishing pressure for males and females ofP. stylifera, resulting in favourable recruitment of the species in the fishery, while this is not so in the case ofM. dobsoni.The study suggests the necessity for reduction in the fishing pressure in order to maintain MSY levels.

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1986.tb00424.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryErrors in estimates of year class strength and mortality among 0‐group plaice can result from migrations. In order to reliably determine the number present, tidal flats and channels in a large and clearly delimited Wadden Sea area (715 km2) were sampled simultaneously using different fishing methods (by‐catch, beam trawls, pushnets, and fyke nets). The numbers of 0‐group plaice calculated for each depth stratum reflected changes in the distribution patterns during the complete diurnal cycle and during the course of the season and proved to be most reliable for estimating the total number in the whole area. In contrast to this, the traditional way of calculating population size by multiplying the arithmetic mean of simultaneous catches resulted in very different numbers which would entail an overestimation of mort

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1986.tb00425.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryGrowth of Boops hoops Linnaeus, 1758 (Pisces, Sparidae) in the golf of LionThe authors give the equations age‐length, age‐mass and mass‐length ofBoops boopsliving in the golf of Lion. Age has been determined by scalimetry. This study has shown that there is no difference between males and females and that the growth (lenght and mass) of the bogue along the French mediterranean coast is less on the Spanish and libanish

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1986.tb00426.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryThe humoral immune response of trout to Egtved virus (VHS) was examined by means of a 50 % plaque neutralization test with complement addition. The test, wich has been adapted for use in microtitre plates, is documented with regard to specificity and sensitivity.Eight weeks after VHS infection by cohabitation at 13 °C neutralizing antibody could be detected in 100% of individually tagged experimental trout. Maximal litres of 10240 were found six weeks after infection. In 36% of the trout antibody was still detectable one year after infection.Neutralizing antibody could be detected also in trout infected with VHS under trout farm conditions. The percentage of positive sera ranged from 4 to 56

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1986.tb00427.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryIn elvers (Anguilla anguilla) imported yearly to a fish farm in Hungary the regular occurrence of aMyxobolusinfection was recorded. The parasite produces oval or spherical plasmodia of 0.1–0.2·0.07–0.12mm in the subcutaneous and intermuscular connective tissue of the head. In each piasmodium about 200 to 400 spores develop which differ morphologically from the spores of allMyxobolusspecies known from the eel and other fishes. Based upon the characteristic location of plasmodia and spore morphology, this parasite is described as a new species,Myxobolus kot

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1986.tb00428.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY