Chaetonotus tachyneusticus Brunson, 1948

Chatterjee, Tapas & Todaro, M. Antonio, 2021, An annotated checklist of the chaetonotidan Gastrotricha from India, Zootaxa 5027 (3), pp. 332-350 : 340

Chaetonotus tachyneusticus Brunson, 1948

Records from India. ANDHRA PRADESH: Kadapa (= Cuddapah), Visakhapatnam – Rao & Mohan (1977, 1987); MAHARASTRA: Nagpur – Visvesvara (1964); GENERAL RECORD: Naidu & Rao (2004), Purushothaman (2017).

Habitat (as in Indian records). Freshwater; among filamentous algae and aquatic angiosperms.

Distribution. USA and India.

Remarks. This species has been reported several times from India; however, morphometric parameters of some of the Indian specimens departs quite a lot from the original description, casting serious doubts on their real taxonomic status. For example, the specimens found by Naidu (1962) are much smaller (total length 110-130 μm vs 203 μm), while the specimens recorded by Rao & Mohan (1987), for which the total body length was not indi- cated, bear a lower number of columns of spines (10 vs 12-16). Only the specimens studied by Visvesvara (1964), according to the author, matched the original description. A redescription of the species from its terra typica (i.e., Michigan, USA) using modern microscopy (e.g., DIC optics) could unveil the presence and shape of the basal scales from which the spines originate, that so far remain undescribed. Information on number and shape of scales would increase the amount and the taxonomic value of the traits on which to base morphological identification. Until this is done, presence of C. tachyneusticus in India should be considered solely provisional. Naidu & Rao (2004) placed this taxon within the subgenus Euchaetontous Schwank, 1990; however, Kisielewki (1997) had included it among the Chaetonotus species of unclear subgeneric position. We support this last choice.