Hypogastrura pomorskii, Skarżyński, 2010

Skarżyński, D., 2010, Hypogastrura Pomorskii Sp. N. From Kyrgyzstan And Notes On The Related Species H. Tatrica (Stach, 1949) (Collembola: Hypogastruridae), Acta Zoologica Academiae Scientiarum Hungaricae 56 (3), pp. 257-263 : 258-261

publication ID	https://doi.org/ 10.5281/zenodo.12584363
persistent identifier	https://treatment.plazi.org/id/03BB8792-2E1B-5A0A-7A62-FE31FC2DFB73
treatment provided by	Felipe
scientific name	Hypogastrura pomorskii
status	sp. nov.

Treatment

Hypogastrura pomorskii View in CoL sp. n.

( Figs 1–10 View Figs 1–11 )

Type material. Holotype: female on slide, Kyrgyzstan, Tien Shan , Barskoon valley, 3,550 m a.s.l., mosses near glacier, 26. VII. 2005, leg. R. J. POMORSKI . Paratypes: 18 females and 15 males on slides, 15 adults and 28 juveniles in alcohol, same data as holotype .

Other material examined. 13 males, 12 females, 3 juveniles on slides, Kyrgyzstan , Tien Shan, Ara-bel valley , 3,800m a.s.l., mosses, 14. VI. 2006, leg. R. J. POMORSKI. All material deposited in the collection of the Department of Biodiversity and Evolutionary Taxonomy, Wrocław University, Poland .

Description. Body length up to 1.5 mm. Colour dark bluish-black. Granulation fine and uniform, 8–12 granules between setae p 1 on abd. V ( Fig. 2 View Figs 1–11 ). Head with slightly protruding tegumentary humps between seate d 2, sd 1 and oc 2.

Chaetotaxy of head typical of the genus, with 2 + 2 v-setae. Setae short and smooth. Trunk sensilla (s) 2–3 times longer than ordinary setae, fine and smooth. Dorsal chaetotaxy of thoracic terga II–III and abdominal terga III–VI as in Figs 1–2 and 10 View Figs 1–11 . Thoracic tergum I with 3 + 3 setae. Thoracic tergum II with setae m 1–6. Thoracic tergum III with setae m 1–2, m 4–6. Setae p 3 and p 7 on abdominal tergum IV present, abdominal tergum V with setae p 2. Subcoxae I, II, III with 1, 3–5, 3–5 setae respectively. Microsensillum on thoracic tergum II present. Thoracic and abdominal terga usually with some additional setae (plurichaetosis).

Antennal segment IV with weakly trilobed apical vesicle ( Fig. 4 View Figs 1–11 ), subapical organite (or), microsensillum (ms), 7–11 (usually 8–9) slightly curved long and moderately thick sensilla. Antennal III-organ with two long (outer) and two short (inner) curved sensilla ( Fig. 5 View Figs 1–11 ). Microsensillum on antennal segment III present. Antennal segment I with 8 setae (seta p’ present).

Ocelli 8 + 8. Postantennal organ with 4 (rarely 5) lobes typical of the genus, equal to or slightly larger than the proximate ocellus. Large accessory boss present ( Fig. 3 View Figs 1–11 ). Labrum with 4 apical papillae. Labral setae 5, 5, 4, prelabrals 4. Maxillary head and labium of the tullbergi type. Outer lobe of maxilla with 2 sublobal hairs.

Tibiotarsi I, II, III with 19, 19, 18 setae respectively. Apical seta A 1 equal to or shorter than inner edge of claws, thin, usually pointed, sometimes indistinctly truncate or clavate. Claws with inner tooth. Empodial appendage with broad basal lamella and apical filament reaching to the middle of the claw ( Fig. 6 View Figs 1–11 ).

Ventral tube with 7–11 (usually 8–9) setae on each side (5–9 in upper and 2 in lower row) ( Fig. 9 View Figs 1–11 ). Retinaculum with 4 + 4 teeth.

Furca well developed. Dorsal side of dens with fine, uniform granulation and usually 7 setae, sometimes 1–2 additional setae proximal to the basal macrochaeta. Mucro short and wide with low lateral, apically fusing lamellae. Ratio dens/mucro 4–5.5 ( Figs 7–8 View Figs 1–11 ).

Anal spines very small, situated on low basal papillae ( Fig. 2 View Figs 1–11 ). Ventro-lateral anal flaps with numerous additional setae.

Etymology. Dedicated to the collector of the type series ROMUALD J. POMORSKI, the excellent specialist in Collembola, who passed away in January, 2010.

Discussion. Hypogastrura pomorskii sp. n. belongs to the sahlbergi group defined as follows: well differentiated antennal segment IV sensilla arranged in two groups: 3 dorsal and 3 or usually more lateral, fine skin granulation (more than

( STACH, 1949), chaetotaxy of thoracic terga II–III

6 granules between setae p 1 on abdominal tergum V), labrum with apical papillae, broad basal empodial lamella, no more than 1, 1, 1 tenent hairs, more than 4 + 4 setae on ventral tube, quadridentate retinaculum, dens with fine granulation and without prominent ventro-apical swelling, mucro without distinct subapical tooth ( BABENKO & THIBAUD 1990, BABENKO & BULAVINTSEV 1993, BABENKO et al. 1994, THIBAUD et al. 2004, SKARŻYŃSKI 2009). The group includes H. austriaca BABENKO & THIBAUD, 1990 ( Austria: Burgenland, BABENKO & THIBAUD 1990), H. fjellbergi BABENKO & BULAVINTSEV, 1993 ( Russia: Novaya Zemlya, Taimyr, USA: Alaska, BABENKO & BULAVINTSEV 1993, BABENKO et al. 1994), H. gennargentui DALLAI, 1970 ( Italy: Sardinia, DALLAI 1970), H. sahlbergi REUTER, 1895 (Europe, Palaearctic?, REUTER 1895, LINNANIEMI 1912, GISIN 1949, LEINAAS 1981, BABENKO et al. 1994), H. szeptyckii SKARŻYŃSKI, 2006 ( Poland: Krakowsko-Wieluńska Upland, Pieniny Mountains, Carpathians, Ukraine: Czornohora, Carpathians, SKARŻYŃSKI 2006, SKARŻYŃSKI & BABENKO 2009), H. tatrica ( STACH, 1949) ( Poland: Tatra Mountains, Carpathians, Slovak Republic: Nizke Tatry Mountains, Carpathians, STACH 1949, NOSEK 1967) and H. tchabensis BABENKO, 1994 ( Russia: foreland of Caucasus, BABENKO et al. 1994). Main differences between H. pomorskii sp. n. and other known species of the group are summarized in Table 1.

The new species is most similar to H. tatrica in having a lobed apical vesicle on antennal segment IV and nearly the same complete chaetotaxy affected by plurichaetosis. The main difference is the presence of setae m 6’ on thoracic terga II–III and m 3 on thoracic tergum III in H. tatrica . Moreover, the two species can be distinguished by the different size and structure of the tibiotarsal tenent hairs which are thick, clavate and clearly longer than inner the edge of the claws in H. tatrica , the dens/mucro ratio (3–3.5 in H. tatrica ); the size and number of cylindrical sensilla on antennal segment IV (7–9 in H. tatrica , rather short and thick); the number of setae on the ventral tube (7–9 in H. tatrica , usually 7–8); and the constant absence of additional setae proximal to the basal macrochaeta of the dens in H. tatrica .

The shape of the apical vesicle and the high number of well differentiated sensilla on antennal segment IV resemble the conditions in H. aushensis SKARŻYŃSKI & BABENKO, 2009 from the Caucasus and H. madera CHRISTIANSEN & BELLINGER, 1980 from North America which are members of related species groups, the crassaegranulata group sensu SKARŻYŃSKI and BABENKO (2009) and the packardi group sensu CHRISTIANSEN and BELLINGER (1998). They clearly differ in body granulation ( H. pomorskii and H. madera : fine, H. aushensis : coarse); size and structure of tibiotarsal tenent hairs (thick, clavate and distinctly longer than the inner edge of the claws in H. aushensis and H. madera ); the dens/mucro plurichaetosis.

*Probably a cyclomorphic species, with a winter form having tooth-like granules and a ventro-apical swelling on the dens and a subapical tooth on the mucro ratio (3–3.5 in H. aushensis and H. madera ); the shape of the mucro ( H. pomorskii and H. madera without subapical tooth, H. aushensis with a small subapical tooth); the number of ventral tube setae ( H. aushensis : 5, H. madera : 4?); and a dens with large granules distally and a ventro-apical swelling in H. madera ( CHRISTIANSEN & BELLINGER 1998, SKARŻYŃSKI & BABENKO 2009).