Journal of Animal and Veterinary Advances, 6 (12): 1409-1415 (2007)

Sexual dimorphism in Artemia urmiana Günther, 1899 (Anostraca: Artemiidae) from the Urmia Lake (West Azerbaijan, Iran)

Alireza Asem*¹ and Nasrullah Rastegar-Pouyani²

1) Protectors of Urmia Lake National Park Society (NGO), Urmia, Iran
2) Department of Biology, Faculty of Science, Razi University, 67149 Kermanshah, Iran

Abstract:

Sexual dimorphism is an important subject in biosystematic and evolutionary studies of the animal kingdom. In this survey, four geographical stations have chosen from the Urmia Lake (west Azerbaijan, Iran). Males and females of Artemia urmiana were examined in order to study sexual dimorphism. The t-Test was used to find out significant differences between means. For classified the male and female samples in each station, Principal Components Analysis (PCA) and Discriminant Function Analysis (DA) were used. PCA analysis let us to separate male and female groups in each station. Also by using DA we can find out that %100 of original groups were correctly classified. This research shows that A. urmiana in each four different station is a sexually dimorphism. Also size difference between male and female can be interpreted as mating advantage; according to Artemia breeding mechanism, female carry male during copulation process then large size of female is necessary for this breeding system and can prove mating process.

Key word: Sexual dimorphism, Artemia urmiana, body size, mating advantage, breeding mechanism