A reconsideration of the taxonomic status of Macrotrachela quadricornifera (Rotifera, Bdelloidea)

The study focuses on the differences between large and small forms of a rotifer species, Macrotrachela
quadricornifera (Rotifera, Bdelloidea), by reviewing the literature and adding further morphological
differences. Evidence from life-history traits, growth patterns and trophi (hard structures of the specialized
rotifer pharynx) morphology suggests that the large and small forms of M. quadricornifera should not be
considered the same species. Macrotrachela vanoyei Schepens, 1954 is re-established as a good species,
differing from M. quadricornifera in the smaller size of body, egg and trophi, as well as the number of
proximal and distal teeth on the trophi.