Paranura reticulata, Smolis, Adrian & Deharveng, Louis, 2015

Smolis, Adrian & Deharveng, Louis, 2015, Diversity of Paranura Axelson, 1902 (Collembola: Neanuridae: Neanurinae) in Pacific Region of Russia and United States, Zootaxa 4033 (2), pp. 203-236 : 205-209

Paranura reticulata sp. nov.

Figs 1–14 , Tables 1–2

Etymology. The name of the species derives from the Latin word net (“reticulum”), underlining the presence of reticulations on its body.

Diagnosis. Body bluish grey. 3+3 eyes on head. Some tubercles present on dorsal side of body, underlined by reticulations. Head with chaetae O, A and E. Head with three ocular chaetae. Thorax I with 2 chaetae De. Thorax II–III with 3 chaetae Di. Thorax II–III with 3 and 4 ordinary chaetae De respectively. Abdomen V with 3+3 chaetae Di. Abdomen V distinctly longer than VI. Abdomen without clavate chaetae. Furca rudimentary with microchaetae. Male ventral organ absent. Tibiotarsi with chaetae M.

Description. Habitus as in Fig. 1 , abdomen V very long, twice as long as the last segment of body. Buccal cone elongate. Body length (without antennae) 0.8–1.70 mm (holotype: 1.55 mm). Colour of body when alive and in alcohol bluish grey. Tubercles developed on central area of head, on abd. V-VI, and in De position on abd I-IV where they are very small, their arrangement as in Figs 1 , 9, 10 . Ordinary dorsal chaetae ( Figs 1 , 9, 10, 13 ) differentiated into short, thin, acuminate microchaetae, medium size, smooth, acuminate mesochaetae and long, smooth (without visible denticles), relatively thick, acuminate macrochaetae Ml and Mc. No plurichaetosis on body.

Head. Antennae slightly shorter than head. Antennal segment II with 12 chaetae. S-chaetae of ant. IV relatively long and thin, S1 distinctly longer than others ( Fig. 6 ). Apical bulb distinct and trilobed ( Figs 7, 8 ). Chaetotaxy of antennae as in Fig. 6 and Tab. 1 . Buccal cone relatively long and rounded at apex ( Figs 3, 4 , 11 ). Maxilla needlelike, mandible tridentate. Chaetotaxy of labium (distally rounded) as in Fig. 4 , labial papillae x absent. Labrum rounded apically, its chaetotaxy 4/2,2 ( Fig. 11 ). Group Vi with 6+6 chaetae ( Fig. 4 ). Groups Vea, Vem and Vep with 4, 3 and 4 chaetae respectively. Dorsal chaetotaxy of head as in Tab. 1 . and Figs 1 , 9 . Chaetotaxy of central area complete, with 3 chaetae Oc and chaetae A, B, C, D, E, F, G, O ( Fig. 9 ). Line of chaetae Di2–De2 crosses line Di1– De1 on head (cross-type, Deharveng 1983). 3+3 large eyes, their diameter about four times as large as the diameter of chaeta Ocm socket ( Fig. 9 ), pigmented in black. Tubercle Af divided into two large ones along midline and a small one with chaeta O ( Fig. 9 ).

Thorax, abdomen, legs. Dorsal chaetotaxy as in Figs 1 , 10 and in Tab. 2 . Ventral chaetotaxy as in Tab. 2 and Figs 2, 5 . S-chaetae very long, distinctly longer than nearby macrochaetae ( Figs 1 , 10, 12 ). S-chaetae formula of body: 022/11111, s-microchaeta on Dl of th. II present. Tubercles well developed on abd. V and VI, on abd. I–IV only small tubercle De present. Tubercles Di of abd. V and VI fused. Furcal remnant with 8 microchaetae and 4–5 mesochaetae ( Fig. 5 ). Male without ventral modified chaetae (“male ventral organ”). Claw without internal tooth. Chaetotaxy of legs as in Tab. 2 . Chaeta M present on tibiotarsus. Chaetae B4 and B5 relatively long ( Fig. 14 ).

Types. Holotype: male on slide, United States of America: Oregon, Oregon Dunes, Siuslaw National Forest, 10 km North of Florence town, Baker Beach, litter from dune-forest with sitka spruce Picea sitchensis , 7.VI. 2009, leg. A. Smolis. Holotype deposited in DIBEC. Paratypes: female (MNHN) and male (DIBEC) on slides, same data as holotype.

Other material. Male, female and 3 juveniles on slides ( DIBEC), USA: Oregon, Blue River Ranger District of Willamette National Forest, neighborhood of H. J. Andrews Experimental Forest, 6.5 km East of Blue River town, c. 520–550 m above sea level, “Cougar 1” site, old-growth forest of Tsuga heterophylla Zone , litter, 27.IX.–3.X. 2006, leg. A. Smolis.

Remarks. Distinct and characteristic shape of the end of body (trapezoidal) and well developed tuberculation place the new species very close to Paranura s-uenoi Yosii, 1955, described from the Japan island Nakanosima ( Yosii 1955). Paranura reticulata sp. nov. differs clearly from its congener in having three ocular chaetae on head (in s-uenoi two chaetae), chaeta F on head equal to chaeta A (in s-uenoi chaeta F is distinctly longer than A), four ordinary chaetae De on th. III (in s-uenoi three chaetae) and three chaetae Di in abd. V (in s-uenoi two chaetae). A more substantial comparison between these species is not currently possible, since the original description of Japan species lacks many characters used in modern taxonomy of Neanurinae . Because of the presence of well developed tubercles on the body Palacios-Vargas and Simón Benito (2007a) suggested to place P. s-uenoi within the genus Nahuanura Palacios-Vargas & Najt, 1986. In contrast to Nahuanura species, P. s - u e no i has however clearly elongated abd. V, and a quite different reticulation pattern (abd. VI reticulate versus non-reticulate, and reticulations of abd. V only lateral, versus only central). Morphological evidence therefore does not support the placement of P. s-uenoi in the genus Nahuanura.

a) Cephalic chaetotaxy––dorsal side.

b) Chaetotaxy of antennae.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe TT th. I 1 2 1 – 0 3 6 13 19 th. II 3 3+s 3+s+ms 3 2 7 6 12 19 th. III 3 4+s 3+ s 3 2 8 6 11 18

Sterna

abd. I 2 3+ s 2 3 VT: 4

abd. II 2 3+ s 2 3 Ve: 5; Vel– present

abd. III 2 3+ s 2 3 –4 Ve: 5–6; Fu: 5 me, 8 mi

abd. IV 2 2+ s 3 9 –10 Vel: 4; Vec: 2; Vei: 2 Vl: 4

abd. V (3+3) 6–7+s Ag: 3; chaetae L‘ and Vl present abd. VI (7+7) Ve: 14; An: 2 mi

Biology. The species was found in litter of two completely different types of coniferous forests. One of them represents unique dune-forest with complete dominance of sitka spruce ( Fig. 15 ), the other one is typical woods for the lower altitude of Cascade Range and was composed of three main tree taxa: Douglas fir Pseudotsuga menziessi , western red–cedar Thuja plicata and western hemlock Tsuga heterophylla . Bisexual form.

Figures

FIGURE 15. Dune – forest with sitka spruce Picea sitchensis, Baker Beach, the type locality of Paranura reticulata sp. nov.

FIGURES 1 – 5. Paranura reticulata sp. nov.: 1, habitus and dorsal chaetotaxy (holotype); 2, ventral chaetotaxy of abdomen; 3, apical part of labrum; 4, chaetotaxy of labium and group Vi; 5, furca rudimentary.

FIGURES 6 – 14. Paranura reticulata sp. nov.: 6, dorsal chaetotaxy of ant. III – IV; 7, dorsal side of apical bulb; 8, ventral side of apical bulb; 9, dorsal chaetotaxy and tubercles of central area of head; 10, dorsal chaetotaxy and tubercles of abd. II – VI; 11, chaetotaxy of labrum; 12, S-chaeta of abd. V; 13, chaeta Di 1 of abd. V; 14, claw and tibiotarsus of the third pair of legs.

Tables

TABLE 1. Cephalic chaetotaxy of Paranura reticulata sp. nov.

Group of chaetae	Number of chaetae	Types of chaetae	Names of chaetae
Cl	4	Mc me	F G
Af	11	Ml Mc me	B A D, E, C, O
Oc	3	Ml me mi	Ocm Ocp Oca
Di	2	Mc me	Di1 Di2
De	2	Ml me	De1 De2
Dl	6	Ml Mc me	Dl5 Dl1, Dl6 Dl2–4
(L+So)	10	Ml me	L1, L4, So1 So2–6, L2–3

TABLE 2. Postcephalic chaetotaxy of Paranura reticulata sp. nov.

Segment, Group	Number of chaetae	Segment, Group	Number of chaetae in adult
I	7	IV	or, 8 S, i, 12 mou, 6 brs, 2 iv
II	12
III ve	5 S-chaetae AO III 5	ap	8 bs, 5 miA
vc	4	ca	2 bs, 3 miA
vi	4	cm	3 bs, 1 miA
d	5	cp	8 miA, 1 brs