TY - JOUR
T1 - Intraspecific life-history variation in Erpobdella octoculata ( Hirudinea
T2 - Erpobdellidae). I. Field study.
AU - Maltby, L.
AU - Calow, P.
PY - 1986/1/1
Y1 - 1986/1/1
N2 - Shorter life histories may be due to high organic loadings, resulting in increased food and hence growth rate (hypothesis 1), or hypoxia, resulting in differential age-specific mortality (hypothesis 2). The Blane Water population had a higher fecundity and shorter life span than the Allander Water population. The latter site was <1km downstream from a sewage outfall and consequently had a higher BOD and lower summer Po2 than the Blane Water site. Despite such differences, the populations did not differ either in individual growth rate or size attained after 1yr; therefore, hypothesis 1 was rejected. Hypothesis 2 predicts that organic enrichment will produce selection for high reproductive investment at the earliest possibility, but an annual/semelparous life history was more prominent at the less polluted site. Selection for different levels of investment under the influence of age-specific mortality pressures may still apply.-from Authors
AB - Shorter life histories may be due to high organic loadings, resulting in increased food and hence growth rate (hypothesis 1), or hypoxia, resulting in differential age-specific mortality (hypothesis 2). The Blane Water population had a higher fecundity and shorter life span than the Allander Water population. The latter site was <1km downstream from a sewage outfall and consequently had a higher BOD and lower summer Po2 than the Blane Water site. Despite such differences, the populations did not differ either in individual growth rate or size attained after 1yr; therefore, hypothesis 1 was rejected. Hypothesis 2 predicts that organic enrichment will produce selection for high reproductive investment at the earliest possibility, but an annual/semelparous life history was more prominent at the less polluted site. Selection for different levels of investment under the influence of age-specific mortality pressures may still apply.-from Authors
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U2 - 10.2307/4750
DO - 10.2307/4750
M3 - Article
AN - SCOPUS:0022889653
SN - 0021-8790
VL - 55
SP - 721
EP - 738
JO - Journal of Animal Ecology
JF - Journal of Animal Ecology
IS - 2
ER -