Spermatozopsis acidophila Kalina (Chlorophyta, Volvocales), a little known alga from highly acidic environments

A strain of the alga Spermatozopsis acidophila from highly acidic environments in the solfatara at Pisciarelli (Naples, Italy) has been studied from the ecological, physiological, morphological and ultrastructural points of view.Its pH optimum (1.0) and its upper limit of pH (1.8) are the lowest recorded for any algal species.Our ultrastructural investigation has confirmed that it belongs to the family Poly-blepharidaceae (Volvocales). A conspicuously developed chloroplast was noted, along with a remarkable quantity of microtubules and E. R. cisternae.