Intra- and interclonal phenotypic and genetic variability of the trematode Maritrema novaezealandensis

Abstract

Explaining the origin and maintenance of phenotypic variation remains a central challenge in evolutionary biology. Using the trematode parasite Maritrema novaezealandensis, we examined variability in several morphological, behavioural, and physiological phenotypic traits at the same time as controlling for genotype by using genetically identical parasite clonal lineages. We measured several morphological traits, photoreactive responses, and survivorship to quantify the amount of phenotypic variation within and among 42 clonal parasite lines. Additionally, we tested Lerner's hypothesis that homozygotes are more variable than heterozygotes and assessed correlations between heterozygosity and p..