Paranura convallis Kasai, 2023

Kasai, Hiro & Sawahata, Takuo, 2023, Four new saproxylic species of Paranura Axelson, 1902 (Collembola: Neanuridae Neanurinae) from Japan, Zootaxa 5339 (6), pp. 501-519 : 513-516

Paranura convallis Kasai sp. nov.

[Japanese name: Murou-ibonashi-tobimushi]

Figs 35–47 , Tables 7–8

Type material. Holotype: female, Japan, Honshu, Nara Prefecture, Uda-shi, Murou (alt. 348 m, 34°32'25"N 136°02'12"E), deciduous broadleaf forest, rotten fallen branch, 18-VII-2020, Hiro Kasai leg. ( NMNS, NSMT-Ap 689) . Paratypes: female ( NMNS, NSMT-Ap 690) and juvenile ( NMNS, NSMT-Ap 691), same data as holotype ; male ( NMNS, NSMT-Ap 692), same locality and habitat as holotype, 21-VI-2021, Hiro Kasai leg ; juvenile ( NMNS, NSMT-Ap 693), same locality and habitat as holotype, 21-VII-2021, Hiro Kasai leg ; female ( NMNS, NSMT-Ap 694), same locality and habitat as holotype, 16-X-2022, Hiro Kasai leg.

Etymology. The new species name refers to the mountain valley habitat.

Diagnosis. 3+3 black eyes on head. Orange body color while alive and white in alcohol. Body relatively thick and plump. Some tubercles poorly developed on the dorsal side and reticulations absent. Ant. II with 11 chaetae. Chaetae A, E, and three ocular chaetae present on head, chaeta O absent. Lateral area on head with 6 chaetae Dl and 9 chaetae (L+So). Th. II–III with 3 and 4 ordinary chaetae De respectively. Abd. IV with 3 ordinary chaetae Dl. Tubercles Di on Abd. V developed and separate, each with 3 chaetae Di. Abdomen without clavate chaetae. Furcal remnant with 3–4 mesochaetae and no microchaetae. Tibiotarsi with chaeta M.

Description. Body length (without antennae) 1.51–2.25 mm in adults. The body orange while alive ( Fig. 35 ), white in alcohol. 3+3 black eyes, two anterior and one posterior. Body relatively thick and plump.

Chaetal morphology. Five types of dorsal ordinary chaetae. Long macrochaetae (Ml) relatively long and thick, feebly serrated, and apically acuminated ( Fig. 46 ); some lateral chaetae longer and strongly acuminate apex. Short macrochaetae (Mc) and very short macrochaetae (Mcc) morphologically similar to Ml, but much shorter. Mesochaetae (me) and microchaetae (mi) similar to ventral chaetae: thin, smooth, and pointed. S–chaetae of tergites thin and smooth.

Antennal morphology and chaetotaxy. Antenna 4-segmented. Ratio of antennal segments as I: II: III + IV = 1:1:1.8–1.9. Dorso-central area on Ant. III–IV strongly granulated ( Fig. 37 ). S-chaetae of Ant. IV short and thick, S1 and S2 slightly thinner than others ( Fig. 37 ). Apical bulb distinct and trilobed. Chaetotaxy of the antennae shown in Table 7b and Figs 37–38 .

Mouthparts. Buccal cone relatively long and rounded at apex. Labrum chaetotaxy 4/2,2 ( Fig. 39 ), prelabral chaetae very tiny. Labium with 4 basal, 3 distal, and 3 lateral chaetae, papillae x absent ( Fig. 40 ). Mandible with 3 teeth ( Fig. 45 ). Maxilla styliform.

Cephalic tubercles and chaetotaxy. Some tubercles poorly developed, reticulations absent ( Figs 36, 47 ). Chaeta O absent. Lateral area with 6 chaetae Dl and 9 chaetae (L+So) (L1–4, So1, So3–6). Dorsal chaetotaxy of the head shown in Table 7a and Fig. 36 . Group Vi with 6+6 chaetae. Groups Vea, Vem, and Vep with 4, 3–4 and 3–4 chaetae respectively.

Body tubercles and chaetotaxy. Some tubercles poorly developed, reticulations absent ( Figs 36, 47 ). Tubercles Di on Abd. V developed and separate, around the tubercles Di raised ( Fig. 47 ). Th. II–III with 3 (Ml+Mcc+mi) and 4 (Ml+Mcc+ 2mi) ordinary chaetae on tubercles De respectively, very short macrochaeta De2 situated close to long macrochaeta De1 ( Figs 41, 42 ), and microchaeta De3 outside the tubercles. Abd. VI weakly bilobed. Dorsal chaetotaxy shown in Table 8 and Figs 36, 47 . Furcal remnant with 3–4 mesochaetae and no microchaetae. Genital plate with 14–24 chaetae in females. An with 2 mi, rarely both or one side absent. Ventral chaetotaxy shown in Table 8 and Fig. 43 .

Legs. Tibiotarsi I, II, and III with 19, 19, and 18 chaetae respectively, chaeta M present. Unguis without inner tooth ( Fig. 44 ). Chaetae B4 and B5 relatively long. Chaetotaxy of the legs shown in Table 8 and Fig. 44 .

Remarks. The new species is most similar to P. tridentata Lee & Kim, 1984 and P. rosea Lee & Kim, 1984 , having 3+3 eyes, tubercle Oc on the head with 3 ocular chaetae, a head without chaeta O, and Abd. V–Vl without clear clavate chaetae. However, the new species can be distinguished by orange body color (in P. tridentata light yellow, in P. rosea red), inner tooth on the claw absent (in P. tridentata absent, in P. rosea present), 3 teeth on the mandible (in P. tridentata 3, in P. rosea 8), 3 ordinary chaetae De on Th. II (2 in P. tridentate , 4 in P. rosea ), 4 ordinary chaetae De on Th. III (in P. tridentata 2, in P. rosea 4), 2 ordinary chaetae Di on Abd. I–IV (in P. tridentata 2, in P. rosea 3), and 3 ordinary chaetae Di on Abd. V (in P. tridentata 2, in P. rosea 3).

Figures

FIGURE 35. Live specimen of Paranura convallis sp. nov.

FIGURES 36–47. Paranura convallis sp. nov.: 36, habitus and dorsal chaetotaxy (holotype); 37, dorsal chaetotaxy of Ant. III–IV; 38, ventral chaetotaxy of Ant. III–IV; 39, labrum; 40, labium; 41, chaetae De of Th. II; 42, chaetae De of Th. III; 43, ventral chaetotaxy of Abd. II–VI; 44, chaetotaxy of tibiotarsus III and unguis; 45, mandible; 46, chaeta Di1 of Abd. V; 47, dorsal chaetotaxy and tubercles of Abd. V–VI. ✕—missing chaetae.