Eukoenenia zariquieyi (Condé, 1951) Conde, 1951

Mayoral, J. G. & Barranco, P., 2013, Rediscovery of the troglobious palpigrade Eukoenenia draco (Peyerimhoff 1906) (Palpigradi: Eukoeneniidae), with notes on the adaptations to a cave-dwelling life, Zootaxa 3635 (2), pp. 174-184 : 181

Eukoenenia zariquieyi (Condé, 1951) stat. nov.

Condé (1951) described the subspecies Eukoenenia draco zariquieyi (Condé, 1951) from a single female collected in Salitre Cave, Montserrat (Barcelona). However, its assignment to E. draco was regarded as uncertain by Condé (1998). In view of the importance of the differences from E. draco , we here elevate Eukoenenia zariquieyi stat. nov. to full species rank.

Comparison of the measurements obtained for both species ( Table 1 ) indicates that E. draco has much longer segments, about three times longer than those of E. zariquieyi , e.g. bta IV 310–336 vs. 78, ti IV 325–341 vs. 78. This is also clear from the ratios between the lengths of the tibiae of three appendages and the total length of the specimens (0.18–0.20 vs. 0.06–0.07). Thus it is possible to clearly differentiate the two species by morphometric data alone.

According to the discussion presented in the section below, regarding the high variability of setae on the sternites, it is difficult to separate the two species based solely on the chaetotaxy. However, the most frequent combination of setae on sternites IV–VI in E. draco is 13 on each segment (including the type). The description of Condé (1951) indicates that the single specimen of E. zariquieyi shows 12, 12 and 10 setae, respectively. The best way to differentiate these two species using the sternal chaetotaxy is by looking at the setae on sternite VI: E. draco usually carries on each side 4–5 a setae (a1–4 or a1–5) plus two s setae (s1–2) (total 13–14 setae), whereas E. zariquieyi carries only 3 a setae (a1–3) plus two s setae (total 10 setae).

The disposition and insertion of the stiff seta (r) on Ibta3 is similar in the two species, although they differ in relation to the length of their tergal edges, those E. draco being much longer. Condé (1951) did not provide a figure of IVbta when describing zariquieyi , but one was later provided by Condé (1977). The arrangement of the setae along the segment is similar, but as mentioned before their lengths differ considerably.