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Genome Sizes of Cyclopoid Copepods (Crustacea): Evidence of Evolutionary Constraint

Genome sizes for 36 species of cyclopoid copepods were determined by DNA-Feulgen cytophotometry of nuclei from adults collected from diverse habitats and locales in North America, South America, Europe, and Asia. Genome sizes are small, show a 20-fold range (C = 0.10-2.02 pg DNA), and vary in a discontinuous fashion. The genomes of cyclopoid copepods are remarkably small and constant within each species, unlike the large and variable genomes of marine calanoid species. These differences may reflect the evolutionary antiquity of marine copepods in relation to marine, brackish, and freshwater copepods, as well as differences in mechanisms used to modulate genome size. The small genome sizes of contemporary cyclopoids provide substantive evidence of evolutionary constraint, possibly favouring small genomes, rapid replication rates and accelerated development as adaptive strategies for survival in often fragmented, stressful, and changing habitats.

Identiferoai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-19374
Date01 April 2006
CreatorsRasch, Ellen, Wyngaard, Grace A.
PublisherDigital Commons @ East Tennessee State University
Source SetsEast Tennessee State University
Detected LanguageEnglish
Typetext
SourceETSU Faculty Works

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