Razieh Taghavizad - Member of Department of Biology, Yadegar -e- Imam Khomeini (RAH) Branch, Islamic Azad University, Tehran, Iran.

A freshwater red algae, Compsopogon caeruleus was collected from current water canal on south of Tehran, Iran for the first time. It lives as epiphyte on Cladophora sp. (green algae) in cold water canal at a temperature of ۸-۱۰°C and at high speed at a depth of ۳۰-۵۰ cm. Thallus was macroscopic filamentous, grey to greyish–green, in the growing season abundantly branched. Branches made an acute angle with the axis (about, ۲۰-۷۰°). Thallus is ۱۸۰-۱۰۰۰ μm in diameter and ۲-۱۰ cm long. In mature thallus, cortex had ۱–۲ polygonal or irregular cell layers with short spine-like branchlets. Cortical cells were established in regular or irregular rows. Chloroplasts were parietal. Monosporangia were cortical and semi-spherical to irregular.

Compsopogon caeruleus, epiphyte, freshwater algae, monosporangia, polygonal, spine-like branchlets