Cryptopygus abulbus, 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 abulbus sp. nov. Figures 3 , 5 , 15-22

Type material.

Holotype and eighteen paratypes: South Africa • Western Cape, Stellenbosch, Jonkershoek Nature Reserve; 33.986883S, 18.955350E; 30 July 2009; C. Janion-Scheepers leg.; litter trap (J2_32), Holotype and eight paratypes deposited on four slides at SAMC, four paratypes on two slides deposited at SMNG, four paratypes on two slides deposited at MSPU, two paratypes on one slide at MNHN.

Diagnosis.

Without globular retractile bulb on Ant. IV. Organite on Ant. IV chili-like. 6+6 ocelli. Maxillary palp simple. Two sublobal hairs. Anterior side of manubrium without chaetae. Tenaculum with two chaetae.

Description.

Body size 0.6-0.7 mm. Body with regular blue pigmentation, slender (Fig. 3 ). Abd. V well separated from Abd. IV and fused with Abd. VI (Fig. 15 ). Cuticle with orthogonal granulation. Ocelli 6+6 arranged as three in anterior and three in posterior group (Fig. 19 ). PAO more than twice as long as ocellus, 0.6-0.7 as long as width of Ant. I and 0.8-1.1 mm as long as inner unguis length. Maxillary outer lobe with two sublobal hairs, one individual with one sublobal hair on one side was found. Maxillary palp simple. Labral formula as 2/5,5,4. Labium with five usual papillae (A-E, Fig. 16 ) and labial formula as in C. bulbus sp. nov. Ventral side of head with 4+4 postlabial chaetae. Ant. I with eleven common chaetae, two ventral s-chaetae (s) and three small basal micro s-chaetae (bms), two dorsal and one ventral, Ant. II with three bms and one latero-distal s, Ant. III with one bms and five distal s (including one lateral). S-chaetae on Ant. IV weakly differentiated. Organite long, of chili-like shape, set apart from subapical micro s-chaeta (Figs 17 , 18 ). Tip of antennae without retractile bulb.

Common chaetae slightly (under very high magnification) serrated at the posterior part of abdomen. S-formula as 4,3/2,2,2,3,5 (s), 1,0/1,0,0 (ms) (Figs 5 , 15 ). Tergal s-chaetae much shorter than common chaetae and well distinguishable. Medial s-chaetae on Th. II-Abd. III situated in mid-tergal position. Macrochaetae smooth and short, 1,1/3,3,3 in number, medial ones on Abd. VI 1.6-2.0 times longer than dens and 2.8-4.1 times longer than mucro. Foil chaetae at the tip of abdomen absent. Axial chaetotaxy as 6-8,5/3,3,3,5-6. Th. I and II without chaetae, Th. III with 2+2 ventral chaetae.

Unguis without teeth. Empodial appendage 0.5-0.7 as in C. bulbus sp. nov. Tibiotarsi without additional chaetae on Leg I and II (21 chaetae), and with a few additional ones on Leg III, about 26 chaetae. Tibiotarsal tenent hairs clavate, 1,2,2 on Tibiotarsi 1,2,3. Ventral tube with 3+3 laterodistal and four posterior chaetae, anteriorly without chaetae (Fig. 20 ). Tenaculum with 4+4 teeth and two chaetae. Anterior furcal subcoxa with 5-7, posterior one with three chaetae. Anterior side of manubrium without chaetae, posterior side with 4+4 laterobasal and 8-9 chaetae on main part, without lateral chaetae. Dens short, without crenulation, with one rigid and short anterior and three posterior chaetae (Figs 21 , 22 ). Mucro bidentate. Ratio manubrium: dens: mucro = 3.3-3.8: 1.7-2.3: 1.

Etymology.

The name is derived from the absence of apical bulb on Ant. IV to stress the difference from C. bulbus sp. nov.

Distribution and ecology.

Currently known from indigenous vegetation in the Jonkershoek Nature Reserve, Stellenbosch.

Discussion.

Unlike C. bulbus sp. nov., the new species has no antennal bulb. Nevertheless, the two species form a rather well-defined group differing from almost all congeners by a simple maxillary palp, two sublobal hairs, chili-shaped organite on Ant. IV, and the absence of chaetae on the anterior side of the manubrium. Concerning the last character, only C. nivicolus (Salmon, 1965) and C. sverdrupi Lawrence, 1978 also lack this pair of chaetae, which is common to other species of the genus. Both mentioned species are inhabitants of Antarctic polar deserts and can hardly be conspecific to C. abulbus sp. nov. found in dry sites in a subtropical climate. These two Antarctic species are very dark and have two clavate tenent hairs (vs. one in C. abulbus sp. nov.) on tibiotarsi I. In addition, C. nivicolus has no mucro (vs. present in the new species) while C. sverdrupi has very small PAO (more than twice longer than ocellus in C. abulbus sp. nov.). Recently, Gressitacantha terranova Wise, 1967 was moved to Cryptopygus (Greenslade, 2015) adding another Cryptopygus species without anterior chaetae on the manubrium. The differences between C. abulbus sp. nov. and C. terranovus are more numerous than those from C. nivicolus and C. sverdrupi (in furca, arms of abdomen, length of macrochaetae, and others).

Figures

Figures 1 - 3. Appearance and macrochaetotaxy of C. bulbus sp. nov., ventral (1) and lateral (2) views, and C. abulbus sp. nov. (3).

Figures 4 - 5. Macrochaetotaxy and s-ms-pattern of C. bulbus sp. nov. (4) and C. abulbus sp. nov. (5). Abbreviations: msms-chaeta, ss s-chaeta.

Figures 15 - 22. C. abulbus sp. nov. 15 Abd. IV and fused Abd. V and V 16 labial palp 17, 18 apical part of Ant. IV, different views 19 ocelli and PAO 20 ventral tube, ventral view 21 furca, lateral view 22 furcal area, ventral view. Abbreviations: org organit, sms subapical ms-chaeta, ss s-chaeta.