Cyphoderus khaochakanus, Jantarit, Sopark, Satasook, Chutamas & Deharveng, Louis, 2014

Jantarit, Sopark, Satasook, Chutamas & Deharveng, Louis, 2014, Cyphoderus (Cyphoderidae) as a major component of collembolan cave fauna in Thailand, with description of two new species, ZooKeys 368, pp. 1-21 : 11-14

Cyphoderus khaochakanus sp. n. Fig. 8

Type locality.

Thailand: Sa Kaeo Province, Khao Chakan District, Tham Meud (Dark Cave) (13°39.541'N, 102°05.414'E), 73 m. above sea level, dark zone in cave, pitfall traps and Berlese extraction, S. Jantarit leg, 29 July 2012 (Sample #Sakaeo-SJ.001).

Type material.

Holotype, male adult (#PSUZC2011.SAK-001H) and 11 paratypes (1 male and 10 of unknown gender) mounted on slides. Holotype and 5 paratypes at PSU (5 slides, 5 subadults, collection #PSUZC2011.SAK-001P-005P) and 6 paratypes at MNHN (6 slides, 1 males, 5 subadults).

Description.

Habitus thick, not troglomorphic, body length about 1.3 mm excluding antennae and furca. Furca well developed, about 2.4 times shorter than body. Body color white. Eyes absent, no ocular patch. Dense cover of scales on head, body and furca (ventrally on manubrium, both sides on dens); scales present on Ant. I–II dorsally, absent on legs and ventral tube. Types of chaetae as in Cyphoderus songkhlaensis sp. n.

Mouthparts. Outer maxillary lobe with one basal chaeta, a simple palp and one sublobal hair. Maxilla with 3-toothed capitulum and a complex of 5-6 pad-shaped lamellae not analyzed in detail. Mandible head stocky, asymmetrical with 5 (left) and 4 (right) teeth. Labial palp with 5 papillae ( A–E) and 13 guards, as in Cyphoderus songkhlaensis sp. n.; hypostomal chaetae (H, h1, h2) present; 4 proximal chaetae. Labial basis formula m,e,l1,l2, with all chaetae smooth or indistinctly serrated, and l2 reduced to a minute but thick mic. Labral formula 4/5, 5, 4 with all chaetae smooth; two chaetae of the mid-row stronger and longer than others (similar to Cyphoderus songkhlaensis sp. n.); dorso-distal limit of primary granules with a deep central incision; labral edge without structure; ventro-distally, two asymmetrical combs with many teeth variously developed and two central tubules.

Antennae. About 1.7 times the length of the head, segmentations I:II:III:IV as 1:3.6:2.5:4.8. Sens and sens-like chaetae present on all antennal segments, of 10 morphological types like in Cyphoderus songkhlaensis sp. n. (Fig. 3A); type-3 mes rather long, apparently smooth under microscopic examination. Scales present dorsally on Ant.I and II (like Fig. 3A11). Ant.I dorsally like Fig. 3B, with scales and ciliated mes (type-1), except 3 basal mic (type-9); ventrally like Fig. 3C, with various types of chaetae (types-1,2,3,5,6 and 9). Ant.II like Fig. 3D, E, both dorsally and ventrally with numerous slender sens and chaetae (types-1,3,4,5,6,7), with scales present dorso-basally; distally, 3-4 dorso-external swollen sens of type-7 and one ventro-external pseudopore. Ant.III like Fig. 3F, G, with various types of chaetae (1,3,4,5,6,7,9,10) not analyzed in detail; dorso-externally, AIIIO like Fig. 3H, typical of Entomobryoidea , with sens 1 to 5 and 8 easily recognized, 2 and 3 being swollen sens of type-7; ventro-externally, one subapical pseudopore. Ant.IV like Fig. 3I, J, devoid of apical bulb, with various types of chaetae (including all types of sens except type-10); subapical organ present dorso-externally as a short and thick rod.

Dorsal chaetotaxy and pseudopores. Patterns and types of chaetae similar to those of Cyphoderus songkhlaensis sp. n. (Fig. 4). Dorsal chaetotaxy and pseudopore patterns (per side) as follows: macrochaetae: 0/0,0/0,0,1,2 from head to Abd.IV (excluding the antenno-basal lines on head and the 7-8+7-8 lateral mac on Abd.IV) (Fig. 4B). Type-5 mes: not analyzed in detail. Trichobothria: 1/0,0/0,2,3,3,0,0 from head to Abd.VI. S-chaetae (sens of types S1, S2, S3 and S4): 0/2,1/1,2,3,4,3,0 from head to Abd.VI, arranged as in Cyphoderus songkhlaensis sp. n. Probably more S-chaetae on Abd.IV where type-5-like mes are often difficult to separate from S4. Pseudopores: 1-2/1,1/1,1,1,1+2,0,0 from head to Abd.VI.

Ventral chaetotaxy of head. 4+4 post-labial mes smooth or very finely serrated along linea ventralis, and one mic between G3 and H3 probably homologous with X (Fig. 2 in Chen and Christiansen 1993).

Legs. Without scales. Trochanteral organ with 18 to 30 simple, straight, smooth chaetae arranged in V-form (Fig. 8A). Tibiotarsus chaetotaxy mostly composed of strong mes, with one thick smooth ventro-subapical chaeta on hind tibiotarsus. Each tibiotarsus with one tenent hair rather stout, apically spatulated, 3/4 to 4/5 as long as inner edge of claw; distal row of 9-10 serrated chaetae irregularly arranged on all tibiotarsi (Fig. 8B). Claw broad, not slender, without tunica; with 2 small teeth at 12% and 25% of inner edge from the tip of the claw, a small dorsal tooth basally and a pair of inner basal teeth of unequal size, the outer one much larger than the inner one (Fig. 8 B). Unguiculus pointed and broad, more than a half as long as claw, lanceolate, with a strong outer tooth (Fig. 8B).

Ventral tube. Without scales. Anterior face with 2+2 long serrated chaetae (like Fig. 7F). Posterior chaetae arranged typically for the genus, with all 5 proximal chaetae (L1, L2 shorter than L1, M) ciliated, accompanied by 2+2 small peg-like microchaetae, and two long smooth distal chaetae; lateral flaps each with 2 short smooth mes (Fig. 8C).

Furca. Tenaculum with 4 teeth on each branch, and a strong, densely serrated, bent uneven chaeta anteriorly (like Fig. 7E). Furca with the same types of chaetae and scales as Cyphoderus songkhlaensis sp. n. (see Figs 7A, B). Manubrium slightly shorter or as long as mucrodens. Dens about 2.3 times as long as mucro. Dorsal side of manubrium (Fig. 8D) with 2+2 pseudopores distally, and about 32-35 mes (fallen in most cases) arranged in two longitudinal stripes, including rather flexible and strongly ciliated mes and a few lateral ones slightly stronger, more straight, feebly serrated (like Fig. 7A type-1), and baso-laterally 2+2 short serrated mes (like Fig. 7A type-3); ventral side covered with oval scales (like Fig. 7B5). Dens (Fig. 8D) elongate, dorsally with 2 rows of feathered scales (like Fig. 7B type-1), 6 external and 5 internal, and 4 ciliated mes (like Fig. 7A type-1) between the two rows; proximal outer part of dens with 3 chaetae, two ciliated (like Fig. 7A type-1) and the most external one smooth (like Fig. 7A type-2); proximal inner part of dens with 2 slightly serrated mes (like Fig. 7A type-1) close to the dens-manubrium articulation (like Fig. 7H); apical outer part of dens with a short serrated mes (like Fig. 7A type-3); long dorso-distal feathered scales fallen in our specimens. Dens ventrally with oval scales (like Fig. 7B types-4, 5), the two long distal ones fallen in our specimens. Mucro straight, elongate, bidentate apically, with an additional minute outer tooth almost at the level of the ante-apical normal tooth (Fig. 8E).

Measurements.

In µm (from type specimen #PSUZC2011.SAK-001H, male).

Etymology.

From the locality "Khao Chakan" district, in SaKaeo province, where this species is found.

Distribution.

Only known from type locality.

Ecology.

Abundant on guano in the dark zone of a karstic cave.