Seasonal Changes and Histological Studies of the Reproductive System of Agabus biguttatus Olivier, 1795 (Coleoptera: Dytiscidae) from Southern Iran

Abstract

Variations in the gross morphology and histology of internal reproductive systems of the male and female of Agabus biguttatus Olivier, 1795, an aquatic beetle, collected from a spring-stream habitat in Bamoo National Park, southwest of Iran in different seasons (mid-spring 2003 to mid-winter 2004), are described and illustrated. By studying the reproductive systems, two phases, developing and degenerating, can be proposed for them. In developing phase (mature, ready for mating) the length and diameter of gonads and accessory glands were larger than in degenerating phase. All the specimens collected in spring and summer demonstrate developing phase, while the autumn and winter specimens show the degenerating one.