Pauropygus projectus, Potapov, Mikhail, Gao, Yan & Deharveng, Louis, 2013

Potapov, Mikhail, Gao, Yan & Deharveng, Louis, 2013, Taxonomy of the Cryptopygus complex. I. Pauropygus - a new worldwide littoral genus (Collembola, Isotomidae), ZooKeys 304, pp. 1-16 : 3-7

Pauropygus projectus sp. n. Figs 1, 3-14

Material.

Holotype female on slide and 13 paratypes (6 on slides, 7 in alcohol): New Caledonia: Iles Loyautés: Ouvéa island: Gossanah: plage de Hoony, collected by flotation from beach sand, 13.11.2000 (sample # NC00-252), leg L. Deharveng & A. Bedos. Coordinates: 166.632°E, 20.4365°S. Material is deposited in Museum National d’Histoire Naturelle, Paris (holotype and 9 paratypes, no male) andin Moscow State Pedagogical University (4 paratypes, including one adult male).

Other material. New Caledonia: Iles Loyautés: Tiga island: Toka village, collected by flotation from beach sand, 31.10.2000 (sample # NC00-145: two on slides; sample # NC00-146: one on slide), leg L. Deharveng & A. Bedos. Coordinates: 167.795704°E, 21.098038°S.

Description.

Size 0.5-0.6 mm. White, without eyes. Cuticle with thin hardly visible primary hexagonal granulation ( “smooth”). PAO flat, roundish, not constricted, about 1.5 as long as inner edge of U.III and shorter than width of Ant.I (Fig. 11). Sublobal plate of maxillary outer lobe small with 3 hairs grouped together, palp simple. Pleural fold with one chaeta (as common for the family) and two high projections (Fig. 3). Labral chaetotaxy as 2/554, middle part of labrum swollen, chaetae in two apical rows set on wide papillae, edge of labrum weakly developed (Fig. 5). Labium with 3 proximal, 6 basolateral and 4 basomedian chaetae and a complete set of papillae (A-E) and guards (16). Papillae B, D and E projected considerably forward, papillae A and C partly reduced and fused with B and D, respectively (Fig. 4). Ventral side of head with 6-7+6-7 postlabial chaetae. Ventrolateral chaetae of head and postlabial chaetae delimit an almost unbroken unsetaceous area. Maxillary head elongated, with four well visible enlarged lamellae of which two have long cilia and two have fine serration. Two remaining lamellae possibly as small weakly serrated projections set in a common cluster at base of claw (Fig. 6). Maxillary claw reduced, single-tipped, finger-shaped, with some weak teeth at the head which are visible in lateral view only (not shown on figure). Pars incisiva of mandible slender, apically with four weak teeth, basal part of pars molaris with two strong hooks (Fig. 7).

Ant.I with many chaetae (more than 20), 1 ventro-basal microchaeta (bms; dorsal bms not differentiated), and 2 thick ventral sensilla (s). Ant.II with 3 rather large bms and 1 thick laterodistal s. Ant.III without bms and with 5 distal s of which two inner as thick and short as outer ones. Male antennal “spurs” unknown. Sensilla on Ant.IV weakly differentiated, as common for the family, subapical organite pin-like and small, subapical microsensillum short and curved (Figs 11, 12).

Dorsal axial chaetom of Th. II–Abd.III as 12-13,7-9/5(4),5(4),5(4). Macrochaetae erect, smooth and rather long, more differentiated laterally on Th. II–III and on posterior half of abdomen, with the whole number as 1,1/3,3,3,4 (Th.II-Abd.IV). Medial macrochaetae on Abd.V about 0.4 as long as dens. Sensilla on tergites clearly differentiated, significantly shorter and slightly thinner than ordinary chaetae. Sensillar formula 20/00113 (s), 00/100 (ms) (Fig. 8). Lateral sensilla on Abd.III, IV in posterior position. Sensilla on Th.II and Abd.III much longer than on Abd.V, sensilla on Abd.IV of medium size (Fig. 9).

Unguis of normal shape, without inner tooth, two lateral teeth forming a weak tunica partly covering dorsal edge of unguis (Fig. 10). Upper subcoxa of Leg I-III with 1,1,4 chaetae, lower subcoxa with 1,10,11 (one individual studied). Ti.I-III with basic set of chaetae (21-22, 22-23, 28), T-chaetae absent. Chaetae on tibiotarsi with irregular distribution, outer side with higher number of chaetae than inner side. Chaetae C7 (inner part of tibiotarsi) either lost or migrated laterally. Modification of chaetae x and B5 on Ti. III in males unknown (no males). Distal tibiotarsal tenent chaetae on Ti.I-III (1-2-2) well developed, not clavate, about 1.5 as long as U.III. Each tibiotarsus with one (sometimes two on Leg II) additional tenent chaeta at middle part. Ti.III with two stick-like chaetae (A6, A7) in distal ring. Ti.I,II with similar thickened chaetae but much less developed. One or two inner chaetae of distal ring of Ti.I-III shorter than others. Three chaetae of distal ring A (two tenent chaetae and one nearby) set apart from distal edge of tibiotarsus, unlike other chaetae of the ring (Fig. 10). Pretarsus with two chaetae, inner one shorter. Ventral tube with 4+4 laterodistal and 2 posterior chaetae. Tenaculum with 4+4 teeth and 1 chaeta. Anterior furcal subcoxa with 13-15 chaetae, posterior with 6-7. Furca of medium size. Anterior side of manubrium with a pair of distal chaetae, posterior one with 8+8 chaetae on the main part and 3+3 on the laterobasal lobes (one individual studied). Manubrial thickening with a pair of additional inner teeth. Lateral parts of manubrium with 1+1 chaetae. Dens slender, anteriorly with 12 (more rarely 11) chaetae. Posterior side of dens slightly crenulated in the medial part, with 5 chaetae of which 3 basal and 2 at the medial part (short inner and long outer) set together on wide papillum. Mucro slender with two teeth of which the subapical one is larger, lamellae not differentiated (Figs 13, 14). Ratio of manubrium: dens: mucro = 2.8-3.4: 4.5-4.6: 1. Anal lobes without microchaetae.

Affinity.

Pauropygus projectus sp. n. differs from Pauropygus caussaneli in number of sensilla on body (20/00113 vs. 31/11221, see also the genus affinity section), relative size of inner and outer sensilla in AIIIO (outer ones smaller than inner ones in Pauropygus caussaneli ), number of posterior chaetae on ventral tube (2 vs. 4), serrated chaetae on upper and lower subcoxae (smooth in Pauropygus caussaneli ), more differentiated chaetal equipment of legs. Besides, Pauropygus projectus sp. n. is larger in size, which may explain higher number of chaetae on Ant.I, parts of legs, axial group of tergites and postlabial area than in Pauropygus caussaneli (see descriptions for details).

Name derivation.

The species has well developed “projections” on the body as: swollen labrum, v-shaped pleural folds, extended labial palp, and antennae projected ahead.

Distribution.

Only from Loyalty Islands in New Caledonia.