Frequency of new marble-colored morph in wild population of Austropotamobius torrentium (Decapoda: Astacidae)
AbstractIn contrast with the usual coloration of stone crayfish (Austropotamobius torrentium), we newly discovered a rare marble morph in a brook in the Czech Republic (Central Europe). During mark-recapture sessions, we captured by hand 1,103 individuals over the 3 years 2008–2010 from which only 5 were marble-colored. This color morph’s frequency of occurrence was thus less than 1% within the estimated subadult and adult stone crayfish population. Although many biological papers and determination keys regarding crayfish are based upon analysis of exoskeletal coloration, recent studies have asserted that this characteristic provides unreliable guidance when determining species inasmuch as it easily results in errors because many crayfish species exhibit an extensive variety of color morphs.