Ceratophysella lobata, Babenko & Skarżyński, 2011

Babenko, Anatoly & Skarżyński, Dariusz, 2011, Ceratophysella lobata sp. n. from Siberia with notes on C. brevisensillata Yosii, 1961 (Collembola: Hypogastruridae), Revue suisse de Zoologie 118 (2), pp. 257-264 : 260-263

Ceratophysella lobata sp. n.

Figs 10-20

Hypogastrura (Ceratophysella) brevisensillata: Fjellberg (1985) : 37

Hypogastrura (Ceratophysella) cf. brevisensillata: Babenko et al. (1994) : 127

MATERIAL EXAMINED: Holotype, female, Russia, Jakutia (Sakha Republic), Suntar-Khayata Mt. Range , upper current of Kyumyume River (63° 13’N 139° 32’E), 1,800 m a.s.l, willow bushes with lichen cover, 9.VII.2002, leg. O. Makarova ( MPGU). – Paratypes, 12 females, 11 males on slides and many specimens in alcohol, same data as holotype ( MPGU, DBET and MNHG) .

OTHER MATERIAL: Russia: 3 females, Ural Mts., Perm’ Province, State nature reserve “Basegi” , Srednii Baseg Mt. (58° 50’N 58° 40’E), alpine tundra, 23.VII.1990, leg. S. Esyunin ( MPGU) . – 2 females, same region but mixed forest with fern cover, 4.IX.1990, leg. S. Esyunin ( MPGU) . – 13 females and 3 males, Siberia, Putorana plateau , vicinity of Yt-Kyuel’ lake (68° 08’N 91° 50’E), 700-900 m a.s.l., nival desert, 28.VII-13.VIII.1996, leg. A. Babenko ( MPGU) . – 7 females and 1 male, Siberia, Taimyr peninsula, upper current of Nizhnaya Agapa River (70° 06N 87° 25’E), tundra, 6.VII-5.VIII.1999, leg. A. Babenko ( MPGU) . – 2 females and 1 male, Chukotka, vicinity of El’gygytgyn Lake (67° 26’ 172° 10’E), tundra, 20.VIII.1974, leg. E. Bondarenko ( MPGU) . – 10 specimens, Chukotka, Aborigen, in fungi on dry ridge, 29.VII.1979, leg. A. Fjellberg ( AF) . – 9 specimens, USA, Alaska, Brook Range, W of Atigun Camp , dry alpine meadow, c. 1600 m a.s.l., 19.VIII.1976, leg. A. Fjellberg ( AF) . – 7 specimens, USA, Alaska,vicinity of Fairbanks, litter in aspen forest, 21.VII.1980, leg. A. Fjellberg ( AF) .

DESCRIPTION: Body length 1-1.2 mm. Color in alcohol light to dark grey-brown. Eye patches black, anal spines light. Granulation fine and uniform, usually 12-15 granules between setae p 1 on abd. V. Dorsal chaetotaxy of B type, macrosetae p 2 on th. II-III set nearly in line with setae p 1, setae m 3 and m 4 on th. II usually present, setae a 2 slightly longer than a 3, setae m 6 absent, setae p 1 and p 2 on abd. IV macro- and micro-setae respectively, setae p 3 absent (Figs 10-11). Arrangement of setae on head typical for the genus. Differentiation of dorsal setae into micro- and macrosetae not strong and more pronounced on last abdominal terga. Setae short, fine, pointed, slightly curved and serrated. Body sensilla p 4 on th. II-III and p 5 on abd. I usually equal to microsetae, thick and sometimes curved. Body sensilla (s) on abd. II-V and lateral parts of th. II-III about as long as macrosetae (Fig 12). Microsensilla (ms) on th. II present. Subcoxae I-III with 1, 2, 3 setae respectively.

Ant. IV with simple apical vesicle, subapical organite (or), microsensillum (ms), 5-7 (usually 7) cylindrical sensilla (2 lateral and 3-5 dorsal) (Fig. 15) and about 15 short curved flattened at tips sensilla in ventral file (Fig. 14). Ant. III-organ with two long (lateral) and two short (internal) curved sensilla (Fig. 15). Microsensillum on ant. III present. Eversible sac between ant. III-IV present. Ant. I with 7 setae.

Ocelli 8 + 8. Postantennal organ about twice as large as single ocellus, with four lobes of which the anterior pair larger than the posterior. Accessory boss present (Fig. 13).

Labrum with 5, 5, 4 setae and without apical papillae. 4 prelabrals present. Labium of the C. armata type. Maxillary head with prolonged denticulate lobe on lamella 5 which only slightly shorter than lamella 4 (Figs 16-17). Outer lobe with 2 sublobal hairs.

Tibiotarsi I, II, III with 19, 19, 18 setae respectively, tibiotarsal tenent hairs nearly as long as inner edge of claws and usually pointed, sometimes truncate. Claws with inner tooth and pair of indistinct lateral teeth. Empodial appendage with broad basal lamella and apical filament reaching inner tooth or slightly beyond (Fig. 18).

Ventral tube with 4 + 4 setae.

Furca well developed. Dens/mucro ratio = ca. 2. Dens with 7 setae (2 inner modified). Mucro boat-like (Fig. 20). Retinaculum with 4 + 4 teeth.

Anal spines equal to or slightly longer than inner edge of claws III, situated on basal papillae (Figs 11, 19).

VARIABILITY: Siberian and available Alaskan material appears to be morphologically homogeneous throughout the distributional range. However Fjellberg (1985) mentioned that in Alaska “exact chaetotaxy and differentiation in macro/microchaetae is rather variable” and alpine specimens from Brook Range “frequently have long, hair-like p 5 sensilla on Abd.I”. It may indicate the presence of the third separate form there apart from C. lobata sp. n. and C. brevisensillata s. l.

ETYMOLOGY: The name reflects the most characteristic feature of the new species - the presence of an additional lobe on one of the maxillary lamellae.

DISTRIBUTION: The new species which seems to be a usual inhabitant of Subarctic Mountains was found in few remote Palaearctic regions from Ural to Chukotka and in Alaska (see map on Fig. 21 and material above).

AFFINITIES: A combination of four features, viz. a full number of ocelli, a chaetotaxy of B type, shortened dorsal sensilla on three first terga and maxillae with prolonged lobe on lamella 5, distinguishes C. lobata sp. n. from all other known species of the ceratophysellan lineage. Thus, only C. brevisensillata and Bonetogastrura nivalis (Martynova) are characterized by the same type of sensillar differentiation, but both have the usual armata-type of maxillae and longer dorsal setae which are more clearly differentiated into macro/microsetae. Apart from this, B. nivalis has only 4 + 4 ocelli and partly reduced chaetotaxy (m 3 always and m 4 usually absent on th. II-III, abd. I-III without m-setae as a rule and p 3 often absent on abd. I-IV).

Shortened dorsal sensilla on thorax similar to those in C. lobata sp. n. are also characteristic of C. bengtssoni (Ågren) , C. microchaeta (Babenko) and B. variabilis (Christiansen) but maxillae of all these species are modified differently with broadened lamella 1 and without prolonged lobe on lamella 5.

The same type of maxillae as in C. lobata sp. n. is known only for C. sigillata (Uzel) , C. sibirica Martynova and C. pseudarmata (Folsom) 1. They can be easily distinguished from C. lobata sp. n. due to long dorsal sensilla on all terga and clearly clavate tibiotarsal tenent hairs (pointed or truncate in C. lobata sp. n.).

Figures

FIG. 21 Known distribution of C. lobata sp.n. (white dots) and C. brevisensillata Yosii, 1961 (black dots, American data according to Christiansen & Bellinger (1980)). Black & white dots in Alaska and Chukotka indicate uncertain records (data from Fjellberg (1985).