Offspring or ornaments? Is carotenoid-based ornamentation in female Arctic charr, Salvelinus alpinus (L.), condition-dependent and traded off against offspring?

In several carotenoids-based ornamented species, females invest carotenoids also into their gametes to increase the quality of the rapidly growing zygote. The extra carotenoids demand may cause females to trade-off valuable carotenoids between ornament and eggs. This may be one reason why females are less showy ornamented than males. In our study-population of Arctic charr, individuals of both sexes vary in degree of conspicuousness of their red abdomen and fins. None of the two carotenoids-based ornaments was significantly associated with either (i) the amount of carotenoids in the egg, although being negative and close to significance, or (ii) potential condition-dependent parameters like relative density of leucocytes, condition-factor and parasitism. This study does not support the 'direct selection hypothesis' to explain the existence of female ornaments, and gives equivocal support for the hypothesis of asymmetrical investment of carotenoids into gametes to explain the less showy ornaments in females when compared with males.