Cryptopygus postantennalis, Potapov & Janion-Scheepers & Deharveng, 2020

Potapov, Mikhail B., Janion-Scheepers, Charlene & Deharveng, Louis, 2020, Taxonomy of the Cryptopygus complex. III. The revision of South African species of Cryptopygus and Isotominella (Collembola, Isotomidae), ZooKeys 945, pp. 99-127 : 99

Cryptopygus postantennalis sp. nov. Figures 23 , 26-31

Type material.

Holotype and three paratype: South Africa • Western Cape, Kogelberg Biosphere Reserve; 34.332650S, 18.950900E; 04 Oct. 2011; C. Janion-Scheepers leg.; Afromontane forest, litter/wood, Tullgren-Berlese extraction; RSA11_KOG007. Deposited on two slides at SAMC.

Other material.

South Africa • Western Cape, Haarwegskloof, Swellendam; 34.335968S, 20.325094E; 18 July 2017; O. Cowan leg. Deposited at MSPU.

Diagnosis.

1+1 ocelli. PAO very long and slender, with large inner denticles. MS-formula 1,0/0,0,1 (ms). All s-chaetae of Abd. V in one dorsal group. Anterior side of manubrium with 1+1 chaetae. Dens of medium length. Mucro tridentate.

Description.

Body size 0.8 mm (only one adult female could be measured). Body mostly white, slender, with rare, scattered pigmentation and a distinct black eyespot (Fig. 23 ). Abd. V well separated from Abd. IV and fused with Abd. VI (Fig. 31 ). Cuticle with orthogonal and hexagonal granulation. One rudimentary ocellus, with a concentration of pigmentation. PAO very long and slender (Fig. 27 ), at least five times as long as ocellus, twice as long as width of Ant. I and 2.8 as long as inner unguis length. PAO constricted, with large "inner denticles". Maxillary head with unmodified lamellae. Maxillary outer lobe with four sublobal hairs, maxillary palp bifurcate. Labral formula as 4/5,5,4, edge of labrum not reduced. Labium with five usual papillae (A-E), guard chaetae e7 present, three proximal and four basomedian chaetae. Ventral side of head with 4+4 chaetae. Ant. I with two ventral s-chaetae (s), distal one much shorter than proximal one, and three basal micro s-chaetae (bms), of which a long dorsal one (Fig. 28 ), Ant. II with three bms and one latero-distal s, Ant. III with one bms and five distal s (including one lateral), without additional s-chaetae. S-chaetae on Ant. IV weakly differentiated. Organite hook-like, close to subapical micro s-chaeta, which is long and bent (Fig. 29 ).

Common chaetae often slightly serrated at the posterior part of Abd. V. S-formula as 4,3/2,2,2,3,5(6?) (s), 1,0/0,0,1 (ms) (Fig. 26 ). Ms on Abd. III as large as s-chaetae. Tergal s-chaetae much shorter than common chaetae and well distinguishable. Medial s-chaetae on Th. II-Abd. III situated in mid-tergal position. On Abd. V, three dorsal s-chaetae (triplet: al, accp1, accp2) short. Two lateral s-chaetae long, migrated to dorsal side and integrated to dorsal triplet (Fig. 31 ). One additional thin chaeta of unclear nature present on lateral side of Abd. V (notated as “ss?” in Fig. 31 and not shown in Fig. 26 ). Macrochaetae smooth and long, 1,1/3,3,3 in number, medial ones on Abd. VI more or less the same length as the dens and 3.8 times longer than mucro. Foil chaetae at the tip of abdomen absent. Axial chaetotaxy for abdomen 4-5,4-5,4-5, ca. 8 (difficult to observe in most individuals). All thoracic segments without ventral chaetae.

Unguis of normal shape, without teeth. Empodial appendage 0.5-0.6 as long as unguis. All tibiotarsi with additional chaetae: 2-3 chaetae on Legs I and II, and about five on Leg III. Tibiotarsal tenent hairs not clavate. Ventral tube with 3+3 laterodistal and 5-6 posterior chaetae, anteriorly without chaetae. Tenaculum with 4+4 teeth and two chaetae. Anterior furcal subcoxa with ten, posterior one with five chaetae (from one individual we could observe). Anterior side of manubrium with 1+1 chaetae. Dens of medium length, with crenulation, with 12 anterior and five posterior chaetae (Fig. 30 ). Mucro tridentate. Ratio manubrium: dens: mucro = 2.7-3.0: 3.6-3.9: 1.

Etymology.

The species is named after its remarkable PAO.

Distribution and ecology.

Known only from type locality and Swellendam, from indigenous vegetation (fynbos and Afromontane forest).

Discussion.

The new species has a unique PAO with large inner denticles visible at any magnification. All s-chaetae of Abd. V (al, accp1, accp2, accp3, accp4) are in one dorsal group, while in other species of Cryptopygus the triplet ‘al+accp1+accp2’ and duplet ‘accp3+accp4’ are placed in dorsal and lateral positions, respectively. The ms-formula 1,0/0,0,1 (vs. 1,1/1,1,1 or 1,0,1,0,0) is also unique.

Figures

Figures 23 - 25. Appearance and macrochaetotaxy of C. postantennalis sp. nov. (23), C. inflatus sp. nov. (24), and C. longisensillus sp. nov. (25).

Figures 26 - 31. C. postantennalis sp. nov. 26 macrochaetotaxy and s-ms-pattern 27 PAO and eye area 28 Ant. I 29 apical part of Ant. IV 30 dens, lateral view 31 Abd. IV and V. Abbreviations: org organit, sms subapical ms-chaeta, ss s-chaeta, bms basal ms-chaeta, msms-chaeta.