Summary
A 3-year-study of a population of this estuarine isopod revealed seasonal changes in the frequency of the “pattern” colour morph. The changes were similar in all 3 years except for the summer period in 1976 which was characterised by abnormal climatic conditions. Changes in morph frequency coincided with changes in the sex ratio. Experiments in the laboratory and with animals in cages on the saltmarsh showed that frequency and sex ratio changes were due to selective mortality under conditions of low salinity and low temperature.
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Khazaeli, A., Heath, D. Colour polymorphism, selection and the sex ratio in the isopod Sphaeroma rugicauda (Leach). Heredity 42, 187–199 (1979). https://doi.org/10.1038/hdy.1979.22
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DOI: https://doi.org/10.1038/hdy.1979.22
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