Van Geel et al 1994: Akinetes (spores) hyaline, tube-shaped, with rounded ends, (14-)21-26(-39) X 9-12 (-18.0) μm. Most spores showing a suture (broken, but still attached) at one end (9-12, 14, 16-18) or both ends (13, 14). Often pores visible at both ends of the spores (14, 17b).
van Geel B, Mur LR, Ralska-Jasiewiczowa M, Goslar T (1994) Fossil akinetes of Aphanizomenon and Anabaena as indicators for medieval phosphate-eutrophication of Lake Gosciaz (Central Poland). Rev. Palaeobot. Palynol. 83:97-105.