Bohonak, A.J., SMITH, BRUCE, Thornton, M. (biology '96). 2004. "Distributional, morphological, and genetic consequences of dispersal for temporary pool water mites" (Acari: Arrenuridae: Arrenurus). Freshwater Biology 49: 170-180.
SUMMARY
1. To determine the consequences of dispersal and gene flow for temporary pond water
mites (Hydrachnida), we compared distributional, genetic, and morphological characters in
the closely related species Arrenurus angustilimbatus and A. rufopyriformis. The former has
larvae that parasitize and disperse on adult mosquitoes, whereas larvae of the latter forego
any association with hosts.
2. Allometrically adjusted egg size and gonopore size were found to be useful characters
for distinguishing between females of the two species.
3. Arrenurus angustilimbatus possesses a broader and more continuous geographic
distribution than its 'direct developing' counterpart. Allozyme heterozygosity was higher
and population differentiation lower in A. angustilimbatus. In addition, populations of A.
rufopyriformis were morphologically divergent, whereas populations of A. angustilimbatus
were not. Isolation by distance analyses on both genetic and morphological characters
indicated that the results were not biased by different sampling regimes for the two
species.
4. These results demonstrate the importance of mosquito parasitism for maintaining
ecological and genetic linkages between A. angustilimbatus populations. More broadly, we
hypothesize that insect-mediated dispersal has contributed to the ecological and evolutionary
success of water mites, because the Hydrachnida lack other obvious adaptations
for dispersing in space or time.
Contributed by Nancy Pierce
