Premium
Life History Consequences of Sexual Dimorphism in a Chernetid Pseudoscorpion
Author(s) -
Zeh David W.
Publication year - 1987
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1939233
Subject(s) - sexual dimorphism , chela , biology , offspring , zoology , population , trait , ecology , demography , genetics , pregnancy , carapace , crustacean , sociology , computer science , programming language
Sexual dimorphism, in the form of sexual difference in pedipalp size, is highly variable among pseudoscorpions in the family Chernetidae. Male pedipalpal chela size ranges from 60 to 150% of that of the female. This study investigated potential life history costs associated with sexual dimorphism, and assessed genetic variation for male chela size in the chernetid Dinocheirus arizonensis. Results demonstrated that nymphal development is prolonged in males. A causal relationship between pedipalpal size and development rate was suggested by (1) a positive correlation between sexual difference in developmental period and sexual dimorphism in chela size, and (2) the absence of sexual differences in adult body mass after removal of the pedipalps. Parent—offspring regression provided some evidence for additive genetic variation underlying male chela size, but also suggested a high genetic correlation between the sexes for the trait. Life history compromises and ecological parameters (population density, patterns of female emergence/receptivity) appear to be important factors influencing sexual dimorphism. However, the degree to which sexual dimorphism actually evolves may depend critically on both the within—sex genetic variance and the between—sex genetic covariance existing in particular chernetid populations.