First report of cyanobacterium Cylindrospermopsis raciborskii from Algerian freshwaters.

This study investigated the first report of the cyanobacterium Cylindrospermopsis raciborskii in Algerian freshwaters. The morphological characteristics of the two morphotypes observed in Lake Oubeira (Algeria) conformed to those of natural populations of C. raciborskii species described in the literature. The two morphotypes produced only straight trichomes. During the study (February 2000-September 2001), this species occurred as a codominant with Microcystis spp., and a peak was observed during the autumn (November 2000) with a remarkable density estimated to be 43 x 10(5) trichomes/L. However, difficulty in isolating and culturing these two morphotypes limited the evaluation of their toxic potential. Copyright 2004 Wiley Periodicals, Inc.