MEPS 340:155-162 (2007)  -  doi:10.3354/meps340155

Heritability for egg size in the serpulid polychaete Hydroides elegans

Cecelia M. Miles1,*, Michael G. Hadfield2, Marta L. Wayne3

1Department of Ecology and Evolution, University of Chicago, 1101 E. 57 Street, Chicago, Illinois 60637, USA
2Kewalo Marine Laboratory, University of Hawaii, 41 Ahui Street, Honolulu, Hawaii 96813, USA
3Department of Zoology, University of Florida, Box 118525, Gainesville, Florida 32611, USA

ABSTRACT: Many quantitative models on the evolution of divergent life histories in marine invertebrates have focused on egg size with little empirical support for the assumption that significant heritability for egg size is present. Narrow-sense heritability (h2) is the proportion of total phenotypic variance in egg size that is made up of additive genetic variance, and is a predictor of short-term response to selection. We estimated h2 for the trait of egg size in the polychaete worm Hydroides elegans using artificial selection and by using a half-sibling breeding design. The cumulative realized heritability was calculated as 0.58 for egg size in a population of H. elegans in Pearl Harbor, Hawaii. Similarly, the half-sib breeding design gave an estimate for h2 of 0.45 for the same population. This indicates that there is substantial potential for egg size to respond to varying selective pressures, at least in the direction of increase.

KEY WORDS: Hydroides elegans · Narrow-sense heritability · h2 · Egg size · Life-history evolution

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