A new Acanthocephala Breizacanthus ligur sp. n. (Palaeacanthocephala: Arhythmacanthidae Yamatugi, 1935) parasite of some species of benthic fishes from the Ligurian Sea]

Breizacanthus ligur sp.n. is described and figured from several benthic fishes from the Ligurian Sea. The host species are: Argentina sphyraena, Chlorophthalmus agassizi, Gadiculus argenteus, Phycis blennoides, Coelorhynchus coelorhynchus, Capros aper, Callionymus phaeton, Helicolenus dactylopterus. The parasites were considered as belonging to the family Arhythmacanthidae Yamaguti, 1935 and to the genus Breizancanthus Golvan, 1969. Breizancanthus ligur differs from the only two known species of the genus B. irenae and B. chabaudi for the number of longitudinal rows of hooks and-or numbers of hooks in each longitudinal row, arrangment of cement glands, length of body and lenght of male genital apparatus ratio, lenght of female genital apparatus and shape of embroyophore.     

Diversity of Rotifera (Monogononta) in wetlands of Río Pilcomayo National Park, Ramsar Site (Formosa, Argentina)

The rotifers at this Ramsar site were inventoried for the first time. A total of 114 taxa, belonging 30 genera were found in samples collected from four aquatic habitats in the Río Paraguay basin, in northern Argentina. The rotifer fauna is characterized by a large proportion of cosmopolitan and tropicopolitan species and few species endemic to the Neotropical Region (5%). In the list, 22% of the taxa are new to the Argentine fauna. Colurella sinistra Carlin is a new record to the Neotropical fauna. Ecological and distributional notes on selected species are included.