Morphological Differentiation of two new Ephemeroporus species (Cladocera, Chydoridae) belonging to the barroisi complex: E. margalefi and E. epiaphantoii, in Spain

Abstract

The Ephemeroporus barroisi complex is of cosmopolitan distribution. To this day, very little is known of the component species, and their study is especially interesting in the Mediterranean region because of its proximity to Syria from which Richard made the original description. In Spain two taxa belonging to the complex occur, which in this paper are described as the new species E. margalefi and E. epiaphantoii. The taxonomic study has been carried out optical and scanning electronic microscopes on individuals of both sexes belonging to different populations. Their inclusion in the barroisi group is clearly justified. In both taxa the anterior margin of the labrum is toothed, and one or several denticules are present on the inferoposterior angle of the valves. The most consistent differential characters concern the shape of the body, the valve ornamentation, the postabdomen structure of both males and females, and the labrum structure. E. epiaphantoii is notably similar to the (very partial) description of Richard and to a population from Iran examined during this study. Due to the biogeographic relationship that characterizes the Mediterranean countries, it is pertinent to suggest that perhaps E. epiaphantoii may release E. barroisi from the nomen dubium status.

E. margalefi and E. epiaphantoii live in very weakly mineralized and transparent waters, rich in vegetation. E. margalefi appears in temporary lagoons and E. epiaphantoii in permanent ones. Both are distributed throughout the western half of the Iberian Peninsula. E. margalefi is more frequent, having been observed in four localities, while E. epiaphantoii has been found only in one, a small reservoir.