Wiyufiloides, Pérez-Schultheiss & Wilson, 2021

Pérez-Schultheiss, Jorge & Wilson, George D. F., 2021, A new genus and species of groundwater isopod of the family Protojaniridae (Isopoda: Asellota: Gnathostenetroidoidea) from southern Chile, Zootaxa 4966 (5), pp. 550-562 : 551-552

Wiyufiloides gen. nov.

Type species: Wiyufiloides osornoensis sp. nov., original designation.

Diagnosis. Mandibular molar process slender, conical, without triturative surface, provided with a comb-like penicil. Maxilliped endite without robust setae; palp article 2 length less than twice articles 1 and 3 length. Pereiopod I propodus strongly subchelate, globose; carpus subtriangular; dactylus uni-unguiculate, longer than half of propodus, posterior margin serrate. Pleopod II protopod of male apex without distal lobe; appendix masculina tapering but not acute, with cuticular ridges; sperm guide tubular, partially enclosed in a short tube, with proximal and distal openings; distal opening subdistally with medially directed open trough and with small angular medial plate.

Etymology. Wiyufilu means “centipede” in Mapudungun, the language of the Mapuche (= earth people), the original inhabitants of Southern Chile. This name was selected because the senior author’s first impression of a specimen attached to underside of a stone was that it resembled a small Lithobiomorphan centipede. The gender of the genus is masculine.

Discussion. An analysis of morphological patterns inside Protojaniridae suggests that the current classification does not reflect the real diversity at generic level. Complex and important characters, such as the structure of the male pleopod II, especially the endopodal appendix masculina, have been poorly described in the past, making its correct interpretation difficult. Pereiopod I also shows a series of transformations in the prehensile adaptation that have not been taken into account. Differences in these features cause Anneckella Chappuis & Delamare, 1957 to appear in two different places in the key. The principal morphological characters ( Table 1) are recovered from published descriptions of protojanirid species. The differentiation of Anneckella into two distinct groups is apparent, the second of which may require recognition as an additional genus. In particular, the pleopod I protopod distal lobe is small and finger-like in the African species, while the Sri Lankan species have a broad rounded distal lobe. Additionally, the latter two species have an endopod that appears to closely resemble species in Enckella Sket, 1982 . To confirm the hypothesis of a new genus-level group for the Protojaniridae , however, a study of types of all described species will be needed.

Possible apomorphies for Wiyufiloides gen. nov. are the vestigial antennal scale (well developed in other species), the apex of pleopod II protopod without distal lobe (present in other species), and male pleopod I covering the remaining pleopods. We note, however, that the absence of the distal lobe occurs more broadly in the Asellota . Moreover, the opercular condition of the pleopod I is not well illustrated in several of the species. Regardless of phylogenetic polarity, these character states appear to be unique to the Protojaniridae ( Table 1). The new genus is similar to Anneckella from South Africa (including A. ficki and A. perbrincki ), in several key features: a mandible molar with accessory penicil, setation of maxilliped endite and structure of pereiopod I, but it differs in having a vestigial antennal scale and the structure of male pleopod II. In the South African group of Anneckella , male pleopod II has a conspicuous protopodal distal lobe that is completely absent in Wiyufiloides gen. nov. The maxillipedal endite distal margin is slightly acuminated in Wiyufiloides gen. nov., which differs from species of Anneckella that have a longitudinal folded and slightly apically expanded endite.

Wiyufiloides gen. nov. differs from Anneckella srilankae Sket, 1982 in the structure of pereiopod I, which is more strongly prehensile, with short carpus, more inflated propodus and with a longer and uni-unguiculate dactylus. Wiyufiloides gen. nov. also differs from A. ficki and A. perbrincki in the structure of male pleopod II that have a protopodal distal lobe.

All other protojanirid genera ( Namibianira , Protojanira , Cuyojanira ) differ in the structure of pereiopod I, which is not propodosubchelate and generally biunguiculate, beside the apomorphies of antenna and male pleopod II ( Table 1).