The male blue crab, Callinectes sapidus, uses both chromatic and achromatic cues during mate choice

Department of Biology, Duke University, Durham, NC 27708, USA.
Journal of Experimental Biology (Impact Factor: 2.9). 04/2012; 215(Pt 7):1184-91. DOI: 10.1242/jeb.067512
Source: PubMed

ABSTRACT In the blue crab, Callinectes sapidus, claw color varies by sex, sexual maturity and individual. Males rely in part on color cues to select appropriate mates, and these chromatic cues may be perceived through an opponent interaction between two photoreceptors with maximum wavelength sensitivities at 440 and 508 nm. The range of color discrimination of this dichromatic visual system may be limited, however, and it is unclear whether male blue crabs are capable of discriminating the natural variations in claw color that may be important in mate choice. By testing males' innate color preferences in binary choice tests between photographs of red-clawed females and six variations of orange-clawed females, we examined both the chromatic (opponent interaction) and achromatic (relative luminance) cues used in male mate choice. Males significantly preferred red-clawed females to orange-clawed females, except when the test colors were similar in both opponency and relative luminance. Our results are unusual in that they indicate that male mate choice in the blue crab is not guided solely by achromatic or chromatic mechanisms, suggesting that both color and intensity are used to evaluate female claw color.

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Available from: Jamie L. Baldwin Fergus, Jul 08, 2015
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    • "Mate choice using chemical signals by one or the other sex, or both of them, would seem to vary among species and may depend on their social context (Borowsky, 1985; Kamio et al., 2000, 2002; Raethke et al., 2004). Alternative mechanisms involved in mate recognition include: visual signals (Baldwin and Johnsen, 2012; Christy and Rittschof, 2011; Christy and Salmon, 1991; Salmon, 1983), chemical signals detected through the contact between partners, since the existence of " contact " sexual pheromones characterized as cuticle exudates was described (Bauer, 2011; Borowsky, 1991; Caskey and Bauer, 2005; Ekerholm and Hallberg, 2005; Herborg et al., 2006; Kamio et al., 2002), and acoustic signals (Popper et al., 2001; Salmon and Horch, 1972). Visual and acoustic signals were commonly described for semi-terrestrial decapod species, principally ocypodids, while " contact " chemical signals were registered for aquatic and semi-terrestrial species. "
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