Summary: Morphological variation of an ornament expressed in
both sexes of the mosquito Sabethes cyaneus
Sandra H. South and Göran Arnqvist
Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
Question: Do elaborate ornaments expressed in both sexes show patterns of phenotypic
variation consistent with selection via mutual mate choice?
Data description: Detailed morphometric data on the striking leg `paddle' ornament of
the sabethine mosquito Sabethes cyaneus: ornament size and shape and size of general
morphological traits. Data derive from 80 males and 80 females from a wild-type laboratory
colony established with individuals collected in Panama.
Search method: Shape variation was analysed using geometric morphometric methods
(elliptic Fourier analyses). We investigated sex differences in the relationships between body size
on the one hand and leg length, ornament size, and ornament shape on the other, using general
linear models. We also explored morphological variation in asymmetry, allometry, and in the
magnitude of phenotypic variation across traits.
Conclusions: These ornaments showed many of the classic hallmarks of a sexually selected
and condition-dependent ornament: (i) phenotypic variation in size was much greater than for
any other trait; (ii) the size of the major part of the paddle showed positive allometry; and
(iii) the degree of fluctuating asymmetry in one component of the shape of the leg paddles