Behavioral and morphological variation in Brachycentrids (Brachycentridae, Brachycentrus spp.) of two northern Michigan streams.

Abstract

Caddisflies of order Trichoptera are an important indicator species for many aquatic habitats. These organisms may be useful in analyzing the effects of global climate change. We observed morphological and behavioral differences of Trichoptera (Brachycentridae Brachycentrus spp.) between Carp Creek and Maple River, two stream habitats of differing temperature and dissolved oxygen levels. We collected samples of larvae using D‐nets and measured length and width of larvae and casings. We expected there to be little differences between morphology and behavior of Brachycentrids in these two streams. Unexpected results showed that Brachycentrids collected in the Maple River were pupating, and some cases contained adult flies. Consequently, the differences in the two sites may be the result of different evolutionary tactics in Brachycentrids.