Pseudechiniscus jiroveci Bartoš, 1963

Tumanov, DV, 2020, Analysis of non-morphometric morphological characters used in the taxonomy of the genus Pseudechiniscus (Tardigrada: Echiniscidae), Zoological Journal of the Linnean Society 188, pp. 753-775 : 770

Pseudechiniscus jiroveci Bartoš, 1963

This species was described by BartoŠ (1963) from China based on five specimens at the larval stage (a two-clawed larva = first instar). Later, specimens attributed to this species were reported from Africa ( Binda, 1984; Pilato et al., 1991), Hawaii ( Binda & Pilato, 1994), Mongolia ( Kaczmarek & Michalczyk, 2006) and China ( Kaczmarek & Beasley, 2002; Beasley et al., 2006). The only character on which the attribution of these specimens to P. jiroveci was based, was a clearly divided posterior part of the scapular plate. However, this character is common in the genus Pseudechiniscus , and in the absence of other characters, cannot be used for the species determination. Unfortunately, postembryonic development of the taxonomically significant traits is completely unknown in Pseudechiniscus , and recent studies on other tardigrade groups show clearly that ontogenetic variability may lead to significant errors in species identification ( Morek et al., 2016), thus the attribution of any adult specimens to the species described by BartoŠ should be considered as doubtful. An investigation of the specimens from Mongolia (Kaczmarek collection) and Africa (Pilato and Binda collection) suggests that they represent two different undescribed species. Taking into account that the original description of P. jiroveci is incomplete and the type material is lost (P. Gąsiorek, pers. comm.), I suggest designating P. jiroveci as nomen dubium in order to avoid erroneous identification of new taxa.