Cyphoderus songkhlaensis, 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 : 5-11

Cyphoderus songkhlaensis sp. n. Figs 2-7

Type locality.

Thailand: Songkhla Province, Rattaphum District, Tham Khao Nui (12°12.227'N, 99°59.524'E), 120 m. above sea level, dark zone in cave, pitfall traps and Berlese extraction, S. Jantarit leg, 05 May 2012 (Sample #Songkhla-SJ.001).

Type material.

Holotype, male adult (#PSUZC2011.SONG-001H) and 44 paratypes (6 males, 3 females, 35 of unknown gender) mounted on slides. Holotype and 29 paratypes at PSU (25 slides, 4 males, 2 females and 23 subadults, collection #PSUZC2011.SONG-001P-030P) and 15 paratypes at MNHN (12 slides, 2 males, 1 female and 12 subadults).

Description.

Habitus thick (Fig. 2A), not troglomorphic, body length about 1.2 mm excluding antennae and furca. Furca well developed, about 2.5 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. Four categories of chaetae: ordinary chaetae (mac, mes and mic), scales, trichobothria and S-chaetae (= sens), described below separately for antennae and body.

Mouthparts. Outer maxillary lobe with one basal chaeta, a simple palp and one sublobal hair (Fig. 2B). Maxilla with 3-toothed capitulum and complex of 5 pad-shaped lamellae not analyzed in detail (Fig. 2C). Mandible head stocky, asymmetrical with 5 (left) and 4 (right) teeth (Fig. 2D). Labial palp with 5 papillae (A-E) and 13 guards, exactly as figured by Fjellberg (1999: fig. 72) (A and C without guards, B with 5 guards, D and E with 4 guards each); three hypostomal chaetae present with H longer than h1 and h2; 4 proximal chaetae (Fig. 2E). Labial basis formula m, e, l1, l2, with all chaetae smooth or indistinctly serrated, and l2 reduced to a minute but thick mic (Fig. 2G). Labral formula 4/5,5,4 with all chaetae smooth; two chaetae of the mid-row stronger and longer than others; dorso-distal limit of primary granules with a deep central incision (Fig. 2F); labral edge without structure; ventro-distally, two asymmetrical combs with many teeth variously developed and two central tubules (Fig. 2C).

Antennae. Less than 2 times the length of the head, segmentations I: II: III: IV as 1: 2.7: 1.6: 3.9. Sens and sens-like chaetae present on all antennal segments, of 10 morphological types (Fig. 3A); type-3 mes rather long, smooth under microscope examination but ciliated under SEM as in Fig. 3A (type-3*). Scales present dorsally on Ant.I and II (Fig. 3A11). Ant.I dorsally (Fig. 3B) with scales and ciliated mes (type-1), except 3 basal mic (type-9); ventrally (Fig. 3C) with various types of chaetae (types-1,2,3,5,6 and 9). Ant.II (Fig. 3D, E) dorsally and ventrally with numerous slender sens and chaetae (types-1,3,4,5,6,7); scales present dorso-basally; distally, 3-4 dorso-external swollen sens of type-7 and one ventro-external pseudopore. Ant.III (Fig. 3F, G) with various types of chaetae (types-1,3,4,5,6,7,9,10) not analyzed in detail; dorso-externally, AIIIO (Fig. 3H) typical of Entomobryoidea , with sens 1 to 5 and 8easily recognized, 2 and 3 being swollen sens of type-7; ventro-externally, one subapical pseudopore. Ant.IV (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.

Body chaetae (Fig. 4A).

1)

trichobothria, ciliated, very long and thin

2)

weakly serrated, spiny mes

3)

serrated or ciliated chaetae, of various length (mes to mac) and thickness

4)

short and thickened mes in trichobothrial areas

5)

thin mes, smooth under microscope examination, but ciliated under SEM

6)

thick minute mic f0 and X on head

7)

thin minute mic of anal valves

S1)

smooth, dark, short, straight, pointed sens

S2)

smooth, hyaline, short, subcylindrical, blunt sens

S 3)

smooth, hyaline, longer, thinner sens

S4)

smooth, rather long, rather thick, blunt sens

Scales oval to rectangular in shape, of various size, covering the whole body dorsally.

Dorsal chaetotaxy and pseudopore patterns (per side).

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: 24-25 (and 1 uneven) /16,6/5,4,6,22,0,0 from head to Abd.VI (approximate numbers) (Fig. 2I for the head).

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. Possibly more 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.

Chaetotaxy and pseudopores on head. As in Fig. 2I (dorsal side). No dorsal mac except the antenno-basal line of 5 mac (f1-f5); f0 as a minute thick uneven mic of type-6 between f1 chaetae; five ciliated clypeal mes and 1 –2+1– 2 pseudopores anteriorly to f1 (Fig. 2H). About 24 dorsal cephalic mes of type-5, subequal, short (Fig. 4A5). Cephalic trichobothria present dorsally at the middle of head with 1+1 mes internally near trichobothria, short and feebly ciliated (Fig. 2I, similar to Fig. 4A3). Ventrally, 4+4 post-labial mes smooth or very finely serrated along linea ventralis, and one mic of type-6 between G3 and H3 probably homologous with X (Fig. 2 in Chen and Christiansen 1993).

Chaetotaxy and pseudopores per tergite. (Figs 4 B–F); values for type-5 mes are indicative). Th.II without mac; with a row of subequal spiny mes anteriorly and laterally, and several rows antero-laterally (type-2), 1+1 antero-lateral sens S1, 1+1 lateral sens S2 not close to S1, about 16+16 mes of type-5, and 1+1 pseudopores close to axis. Th.III without mac; with 1+1 antero-lateral sens S2, about 6+6 mes of type-5, and 1+1 pseudopores.

Abd.I without mac; with 1+1 lateral sens S1, about 5+5 mes of type-5 and 1+1 pseudopores.

Abd.II without mac; with 2+2 trichobothria, 6+6 modified mes around the trichobothria (type-4, Fig. 4C), 1+1 sens S2 (Fig. 4C) and 1+1sens S3 (Fig. 4C), about 4+4 mes of type-5, and 1+1 pseudopores. Abd.III with 3+3 trichobothria, 1+1 mac, 9+9 modified mes of type-4 on trichobothrial areas (3+3 near the internal trichobothria and 6+6 near the two external trichobothria, Fig. 4D), 3+3 sens in trichobothrial areas (1+1 S1 and 2+2 S3, Fig. 4D), about 6+6 mes of type-5, and 1+1 pseudopores. Abd.IV with 3+3 trichobothria, 2+2 mac, 4+4 modified mes of type-4 in the anterior trichobothrial area (none in the posterior trichobothrial area, Figs 4E and 6), 2+2 sens S3, 2+2 sens S4 near axis, about 22 –23+22– 23 mes, 2+2 sens S4 ahead pseudopores, in tandem with 2+2 short probably type-5 mes (Fig. 4F), 1+1 serrated mes of type-3 in tandem with 1+1 sens S3 posteriorly, and 3+3 pseudopores (1+1 in the middle of Abd.IV, 2+2 in the posterior margin of the tergite, behind a posterior row of 4+4 mes). Abd.V without pseudopore or mes of type-5; with 3+3 sens S3 and several short mac and mes.

Legs. Without scales. Trochanteral organ with 11-22 simple, straight, smooth chaetae arranged in V-form (Fig. 7C). Tibiotarsus chaetotaxy mostly composed of strong ciliated mes, with one thick smooth ventro-subapical chaeta on hind tibiotarsus. Each tibiotarsus with one tenent hair rather stout, apically spatulated, 4/5 as long as inner edge of claw; distal row of 9-10 serrated chaetae irregularly arranged on all tibiotarsi (Fig. 7D). Claw broad, not slender, with a weak or inconspicuous tunica; with one tooth at 40% 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. 7D). Unguiculus pointed and broad, more than half as long as claw, lanceolate, with a strong outer tooth (Fig. 7D).

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

Furca. Tenaculum with 4 teeth on each branch, anteriorly with strong, densely serrated, bent uneven chaeta (Fig. 7E). Furca with three types of chaetae (Fig. 7A) and 5 types of scales (Fig. 7B). Manubrium about 1.2 times as long as mucrodens. Dens about 2.3 times as long as mucro. Dorsal side of manubrium (Fig. 7H) 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 (Fig. 7A type-1), and baso-laterally 2+2 short serrated mes (Fig. 7A type-3); ventral side covered with oval scales (Fig. 7B type-5). Dens (Fig. 7H) elongate, dorsally with 2 rows of feathered scales (Fig. 7B type-1), 6 external and 5 internal, and 4 ciliated mes (Fig. 7A type-1) between two rows; proximal outer part of dens with 3 chaetae, two ciliated (Fig. 7A type-1) and the most external one smooth (Fig. 7A type-2); proximal inner part of dens with 2 slightly serrated mes (Fig. 7A1) close to dens-manubrium articulation; apical outer part of dens with one short serrated mes (Fig. 7A type-3); long dorso-distal feathered scales fallen in our specimens. Dens ventrally with oval scales (Fig. 7B types-4, 5), the distal internal one almost as long as mucro (Fig. 7B2, 3). Mucro straight, elongate, bidentate apically, with one minute external tooth almost at the level of the ante-apical normal tooth (Fig. 7I).

Genital plate. Male genital plate of the circinate type (sensu Christiansen 1958), with 6 genital mic and 15-16 circumgenital short, thin, smooth mes (Fig. 7K). Female genital plate with 2+2 mic (Fig. 7J).

Measurement.

in µm (from type specimen #PSUZC2011.SONG-001H, male).

Etymology.

From the name of the province “Songkhla” where this species was discovered.

Distribution.

Only known from the type locality.

Ecology.

Collected on guano in the dark zone of a cave developed in a karst covered with rainforest.

Discussion.

The new species is similar to Cyphoderus javanus Börner, 1906 and to Cyphoderus sumatranus Yoshii, 1987. The only detailed description of Cyphoderus javanus is that of Cyphoderus borneensis by Yoshii (1980, 1987), which was synonymized with Cyphoderus javanus by the same author in 1992. Cyphoderus songkhlaensis sp. n. differs from Cyphoderus borneensis as described by Yoshii in the following combination of characters: the posterior face of its ventral tube with chaetae L1 and L2 ciliated but M smooth (given however as ciliated in Yoshii 1980) (versus L1, L2, M all ciliated chaetae), anterior mac of ventral tube serrated versus smooth, spatulate versus blunt tenent hairs, no versus a few smooth basal chaetae on manubrium and claw with two inner teeth versus one inner tooth on claw.

Cyphoderus songkhlaensis sp. n. differs from Cyphoderus sumatranus by its ciliated clypeal chaetae (versus smooth in Cyphoderus sumatranus ), the presence of one sublobal hair on outer maxillary lobe (versus none in Cyphoderus sumatranus ) and the posterior face of its ventral tube with chaetae L1 and L2 ciliated but M smooth (versus L1, L2, M all ciliated chaetae). The new species is known from caves like Cyphoderus sumatranus , but Cyphoderus javanus has been reported from diverse habitats: termite nests, forest soil and caves.