Notes on South American tardigrades with the description of two new species:<i>Pseudechiniscus spinerectus</i>and<i>Macrobiotus danielae</i>

Abstract

Abstract Five species of tardigrades from South America are recorded, two of which, Pseudechiniscus spinerectus and Macrobiotus danielae, are new to science, and one, Doryphoribius flavus (Iharos 1966), is new for South America. Pseudechiniscus spinerectus differs from P. bidenticulatus Bartoš 1963 and P. bartkei Weglarska 1962 by having median plate 2 divided into two portions, spines of the pseudosegmental plate more developed; it differs from P. bidenticulatus by having inner claws with a spur; it differs from P. bartkei by having the caudal portion of the scapular plate faceted, more dense plate sculpture with dot size increasing from the head to the terminal plate, striae joining the dots to each other less evident. P. spinerectus differs from P. ramazzottii Maucci 1952 and from P. brevimontanus Kendall-Fite & Nelson 1996 in the following features: spines of the pseudosegmental plate more developed, dots of plate sculpture joined to each other by striae. it differs from P. ramazzottii also by having the papilla of the hind legs clearly shorter; it differs from P. brevimontanus also for some details of the ventral cuticular sculpture. Macrobiotus danielae belongs to the richtersi-group; it is very similar to Macrobiotus vanescens Pilato et al. 1991 from which it differs in the following features: smaller body size, wider buccal tube, slightly longer microplacoid, more slender claws, some characters of the eggs (reticular sculpture of the conical processes with less prominent ridges; less evident apical indentation; basal areolae smooth). KEY WORDS: tardigradesSouth American fauna Pseudechiniscus spinerectus n. sp. Macrobiotus danielae n. sp.