Pseudachorutes octosensillatus Zoughailech, Hamra-Kroua & Deharveng, 2016, sp. nov.
Creators: name: Zoughailech, Abdelmalek
name: Hamra-Kroua, Salah
name: Deharveng, Louis
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Entognatha
Collembola
Neanuridae
Pseudachorutes
Pseudachorutes octosensillatus

description: Pseudachorutes octosensillatus sp. nov.
Figs 3, 4, 7B, C, 8 D, Table 3
Type material (leg. A. Zoughailech). Holotype female on slide, Algeria, Skikda, Collo Massif, near Oued Z’hor village, 40 m alt., Quercus canariensis and Q. suber forest, in rotten wood, x.2012. Type locality coordinates: 36.916717°N, 6.325421°E. Six paratypes on slides: 1 female, ibidem, in rotten wood, iii.2014; 2 males, 1 female and 1 juvenile, ibidem except: in litter, iii.2014. Holotype female and 3 paratypes on slides deposited at LBEA; 3 paratypes on slides deposited at MNHN.
Description. Body length without antennae 0.819 mm (holotype female) and 1.230 mm (paratype female). Habitus usual for the genus. Color in ethanol bluish-grey. Dorsal granulation of the tegument regular and moderately large, stronger posteriorly. Secondary granules rounded, 1.2–1.8 times wider than chaeta sockets in diameter on head and body. Six to nine secondary granules between chaetae P1 on Abd V.
Antenna (Fig. 3 A). Antennae shorter than head. Ant. I with 7 chaetae, Ant. II with 12 chaetae (11 mes and a ventro-lateral mic). Ant. III with 17–18 ordinary chaetae and 5 S-chaetae. Ant. III and IV fused dorsally. AIIIO externo-distal, consisting of two small rod-like S-microchaetae, surrounded by two subcylindrical guard S-chaetae, ventral one slightly longer than dorsal one, similar in size to Ant IV S-chaetae, and a ventral S-microchaeta. Ant. IV with 8 short, thin, subcylindrical, bent S-chaetae dorsally (S1 to S8), the dorso-external S-microchaeta present, no thickened S-chaeta ventro-basally, subapical organite present, apical bulb simple or slightly trilobed.
Head (Figs 3 B–E, 7B, C). PAO roundish,1.5 times larger than closest eye, with 9 to 12 vesicles, sometimes overlapping. 8+8 eyes. Buccal cone moderately elongated. Mandible very thin, with 3 teeth; maxilla styliform. Labrum triangular, basally wide, rather short, with ventro-distal sclerifications ending in a blunt ogiva. Labral formula:?/ 4,3,2,4. Labium short, with 11 ordinary chaetae: 4 basal chaetae (E, F, f,G), 3 distal chaetae (A,C,D present, B absent) and 4 lateral chaetae; papillate chaeta L absent; no x-papilla detected. Peri-labial area with 5+5 subequal chaetae, of which 2+2 along the linea ventralis. Dorsal head chaetotaxy constituted of ordinary subequal mesochaetae. Central area with 20–21 chaetae (d1 to d5, sd1 to sd5); variations due to the presence of either one unpaired or two asymmetrical chaetae d1, sometimes asymmetries or duplication of other chaetae), a0 absent. Ocular area with 3 chaetae. Postero-internal area with 4+4 chaetae (c1, c2, p1, p2).
Tergites (Fig. 3 F, Table 3). Chaetal pattern summarized in Table 3. Chaetotaxy constituted of subequal ordinary mesochaetae and S-chaetae, the former about 1/3 shorter than the latter. S-chaetae formula per half tergite: 2+ms,2/ 1,1,1,1,1. Position of S-chaetae from Th. II to Abd. V 3,3/4,4,4,4,2. Th. II without chaeta a2. Th. II–III without chaeta De4 Abd. V with chaeta p2 absent. Abd VI with 13 dorsal chaetae.
Thoracic sternites and legs (Fig. 4 A). Th. I–III sternites without chaetae. Claw with a small inner tooth, without lateral teeth. Tibiotarsi I, II and III with 19, 19 and 18 chaetae (M present, no clavate tenent hairs). Femora I, II and III with 13, 12 and 11 chaetae. trochanters I, II and III with 6, 6 and 5 chaetae. Coxae I, II and III with 3, 7 and 7 chaetae. Subcoxae 2 of legs I, II and III with 0, 2 and 2 chaetae.
Abdominal sternites and appendages (Figs 4 B, C, 8D). Ventral tube with 4+4 chaetae. Abd. II with 4+4 chaetae. Abd. III not clearly separated from Abd. IV, with 4 – 6+4 – 6 anterior chaetae and 2 – 3+2 – 3 posterior chaetae with frequent asymmetries, which may belong as well to Abd. IV. Furca well developed. Tenaculum with 3+3 teeth. Manubrium with 12 – 13+12 – 13 posterior chaetae including (3) – 4+(3) – 4 chaetae VL, with VL3 slightly longer. Dens with 6 chaetae, 2.2 – 2.4 times longer than mucro. Mucro weakly hooked distally, with a broad lateral lamella. Abd V with 3+3 chaetae Ag, in continuity with more lateral chaetae VL which are not individualized as a chaetal group. Female genital plate with 1+1 genital microchaetae and 10 – 15 circumgenital chaetae. Male genital plate with 4+4 genital microchaetae and about 15 circumgenital chaetae. Abd VI with 14 chaetae Ve (and a 15th chaeta slightly longer than others and set apart laterally). Anal flaps with 3 mic hr each. No modified ventral chaetae in male.
Etymology. In reference to the presence of 8 S-chaetae on Ant. IV, a number which is higher than in other species of the genus.
Ecology. Pseudachorutes octosensillatus sp. nov. was found as isolated specimens among large populations of the much more common P. deficiens, in Quercus suber and Q. canariensis forests of the Collo massif. The species is bisexual.
Discussion. The species Pseudachorutes octosensillatus sp. nov. is the only species of the genus to have 8 Schaetae and one S-microchaeta on Ant. IV. This pattern has only been recorded so far in Pseudachorutella balcanica, and probably other European species of the genus (Deharveng 1981, Smolis & Skarżyński 2007). The 8 S-chaetae of P. octosensillatus are likely homologous of chaetae S1 to S8 which characterize the Neanurinae subfamily. The dorsal mou-chaetae and the chaeta "i" (slender, shorter and more acuminate) are also arranged following a pattern similar to that of Pseudachorutella and Neanurinae (Fig. 3 A and Deharveng 1981, Fig. 2). The dorsal chaetotaxy of Ant. IV in P. octosensillatus sp. nov. differs from that of Pseudachorutella by the lack of dorsal chaetae b1. It differs from that of Neanurinae by the presence of a microchaeta ms and the lack of the dorsal chaetae b1 and a1. These very similar chaetotaxic patterns expressed in three otherwise very dissimilar taxa is likely a convergence.
description: Published as part of Zoughailech, Abdelmalek, Hamra-Kroua, Salah & Deharveng, Louis, 2016, New species of Pseudachorutes (Collembola: Neanuridae) from Northeastern Algeria, pp. 557-568 in Zootaxa 4158 (4) on pages 561-563, DOI: 10.11646/zootaxa.4158.4.7, http://zenodo.org/record/259708