ISSN:
1573-5117
Schlagwort(e):
gastropod
;
prosobranch
;
Gibbula umbilicalis
;
reproduction
;
range
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract Size/frequency samples have been taken from populations of the trochid gastropod Gibbula umbilicalis at a number of sites around the British Isles each year since 1978. In the North of Scotland, close to the limit of the species distribution, recruitment was generally poor and populations were sparse and dominated by large old individuals. While such poor recruitment may reflect the low density of adults and the shortage of nursery areas, a distinct temporal pattern of recruitment was also evident. At the start of our study, the majority of sites had population structures biased towards young animals implying that conditions for the settlement of larvae or their subsequent survival had been favourable over a wide area. In the years that followed only the enclosed Loch Eriboll regularly received substantial recruitment. Further to the south, in Wales and S.W. England, recruitment was usually more regular, populations were more dense and individuals smaller.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00026743
Permalink
