Remarks on some species of tardigrades from South America with the description of two new species

Abstract

Six species of Tardigrada are reported from South America, two of which, Isohypsibius sabellai and Hypsibius septulatus, are new to science. Isohypsibius sabellai has a cuticle with about 20 undulations and reticular sculpture, a pharyngeal bulb with apophyses and two macroplacoids. It differs from Isohypsibius undulatus Thulin, 1928 in some characters of the cuticular sculpture, the shape and size of the claws (in I. sabellai they are longer and more slender), and by having the stylet supports inserted on the buccal tube in a more caudal position. Hypsibius septulatus has an unsculptured cuticle with about 22 dorsal undulations, two macroplacoids and the septulum, a cuticular bar near the internal claws on the first three pairs of legs and near the anterior claw of the hind legs, and a short cuticular bar between the claw bases on all legs. Other species reported are: Macrobiotus coronatus De Barros, 1942; Macrobiotus danielae Pilato, Binda, Napolitano and Moncada, 2001; Hypsibius dujardini (Doyère, 1840); and Diphascon (Adropion) onorei Pilato, Binda, Napolitano and Moncada, 2002.