Troglobius Palacios-Vargas & Wilson, 1990

Zeppelini, Douglas, Silva, Diego Dias da & Palacios-Vargas, Jose G., 2014, A new species of Troglobius (Collembola, Paronellidae, Cyphoderinae) from a Brazilian iron cave, Subterranean Biology 14, pp. 1-13 : 1

Taxon classification Animalia ORDO FAMILIA

Genus Troglobius Palacios-Vargas & Wilson, 1990

Type species.

Troglobius coprophagus Palacios-Vargas & Wilson, 1990

Diagnosis.

Habitus as Entomobryomorpha , eyeless, without pigment. Body with ciliated chaetae and hyaline ovoid scales. Mesothorax and metathorax not humped or bent. Ant. IV not subdivided. Labial chaetotaxy with chaetae: M1, M2, R, E and L1 present, L2 absent. Head bearing two pairs of trichobothria. Mucro elongate, four times as long, or more, than its greatest width, with many serrations along one or both dorsal lamellae. Dens without spines, anterior side covered with scales. A couple of large scale, about the same size as mucro, present on apex of anterior surface of dens. Posterior side of dens with, at least, three rows of chaetae and scales. Some (or most) scales, or thick chaetae, of internal row deeply fringed. In other rows only some distal chaetae modified. Unguis and unguiculus with winged teeth.

Remarks.

The original description places the genus in the family Paronellidae Börner, 1913. Soto-Adames et al. (2008) define the subfamilies Paronellinae and Cyphoderinae as follows:

Separation between Paronellinae and Cyphoderinae is based on the presence of fringed dental scales in the latter and their absence in the former. All cyphoderines are eyeless, whereas the majority of paronellines have eyes. In addition, all cyphoderines have scales, whereas many paronellines lack these scales.

The morphology of the dental scales, the absence of eyes, the shape of mucro and the presence of large scales at the tip of dens, about the same size as mucro, indicate that the genus Troglobius belongs to the subfamily Cyphoderinae (with 128 species distributed among 13 genera of blind Collembola) instead of Paronellinae (with 384 species in 27 genera) as proposed by Bellinger et al. (2013).

In the new proposed diagnosis for the genus, we conclude that the labial chaeta “R” is present, normal shaped, and variable in size, while chaeta L2 is always absent. An additional lateroventral trichobothria, close to the basis of antennae is present in each side of head, this feature is also seen in Cyphoderus , another genus of Cyphoderinae . The genus Troglobius can be differentiated from other Cyphoderinae by the shape of the mucro, which has, at least one lamella serrated.

Description of the new species