Morphological variation of some Ophiocytium Nageli species (Xanthophyceae) of temporary body waters from Mexico State

Abstract

The species belonging to genus Ophiocytium Nageli (Mischococcales, Xanthophyceae) have a world distribution in acidic to neutral environments; these species are little common in floristic records in our country. The suitable conditions observed in Santa Ana, in Mexico State, for development of Ophiocytium species made possible their study for several months (December 1993 - April 1995). Nine morphotypes were characterized. Although they may correspond to species according to bibliography, only five were determined after evaluation of morphological characters that are used in the specific delimitation. Additionally, the variation of O. parvulum, the most abundant species, was used to propose an annual development pattern that may be extrapolated to all species in Santa Ana.