Original paper

Light and electron microscope studies of Asterocapsa salina, spec. nova (Cyanophyta/Cyanoprokaryota)

Hindák, František; Šmarda, Jan

Abstract

A new representative of the genus Asterocapsa Chu, A. salina, is described based on morphological and environmental criteria. The samples of the species were taken from a sand bank of a pool on the dry salt lake Chott-el-Djerib, the largest saline lake in the Sahara desert, Tunisia, and the cultures derived thereof were studied by light and electron microscopy. The cells in young cultures were oval to shortly cylindrical, blue-green, with a hyaline and smooth mucilaginous envelope. Old cultures were yellowish to dark brown in colour, the cells thereof were regularly rounded and covered by a thick yellowish-brown, irregular ragged sheath, as it is characteristic for the genus Asterocapsa. Cells were spherical, considerably smaller than their sheath, blue-green to grey, dividing into two equal parts. Daughter cells were liberated by a large rupture in an ornamented sheath of the mother cells, or can stay in the mother sheaths, but in both cases grew and repeatedly divided again forming 2-4-celled colonies. No nanocytes observed. The new species differs from all others by solitary cells not forming composed colonies, yellowish-brown, irregular ragged sheath and its occurrence in a hypersalinic habitat.

Keywords

asterocapsalife cyclecolonial cyanophytes/cyanobacterianew speciessalt laketunisia