Pauropygus caussaneli (Thibaud, 1996) Thibaud, 1996

Potapov, Mikhail, Gao, Yan & Deharveng, Louis, 2013, Taxonomy of the Cryptopygus complex. I. Pauropygus - a new worldwide littoral genus (Collembola, Isotomidae), ZooKeys 304, pp. 1-16 : 7-10

Pauropygus caussaneli (Thibaud, 1996) comb. n. Figs 2, 15-20

Cryptopygus caussaneli Thibaud, 1996

Cryptopygus riebi Barra, 1997 n. syn.

Material.

Holotype and paratypes of Cryptopygus caussaneli : Mauritania (Aftout-es-Sahel); holotype and paratypes of Cryptopygus riebi : South Africa (Sodwana Bay, Natal Province); two paratypes of Cryptopygus axayacatl Palacios-Vargas & Thibaud, 2001: Mexico (Guerrero, Acapulco); material of J.-M.Thibaud identified by him as Cryptopygus caussaneli from Senegal, Morocco, Congo, Madagascar, Maurice and Mayotte Islands. More precise labels in the associated publications ( Palacios-Vargas & Thibaud, 2001; Thibaud & Ndiaye, 2006; Thibaud & Boumezzough, 2006; Thibaud, 2008). All specimens are kept in the Museum national d’Histoire naturelle of Paris (France).

Redescription.

White, without eyes. Size up to 0.4 mm. Cuticle smooth. PAO about 1,9 as long as inner edge of U.III and shorter (0.7) than width of Ant.I. Outer (Fig. 20) and inner mouthparts principally as in Pauropygus projectus . Ventral side of head with 5+5 postlabial chaetae. Ant.I with 14-15 chaetae, 1 ventro-basal microchaeta (bms; dorsal bms not differentiated), and 2 thick ventral sensilla (s), short and long. Ant.II with 3 bms and 1 thick laterodistal s. Ant.III without bms and with 5 distal s of which two inner thicker and longer than outer ones. Male antennal “spurs” present on Ant.II, III and basal part of Ant.IV.

Dorsal axial chaetom of Th. II–Abd.III as 10,6/4,4(3),4(3). Thorax without ventral chaetae. Macrochaetae smooth, with the whole number as 1(2),1(2)/3,3,3,4 (Th.II-Abd.IV). Medial macrochaetae on Th.II-Abd.III hardly differentiated. Medial macrochaetae on Abd.V about 0.4 as long as dens. All sensilla of thorax and medial sensilla of abdomen nearly as long as ordinary chaetae and hardly visible, lateral sensilla on Abd.III-V shorter than ordinary chaetae. Microsensilla short but well visible. Sensillar formula 31/11221 (s), 00/100 (ms) (Fig. 15-18). Sensilla in posterior position. (Fig. 16).

Unguis of normal shape, without inner tooth, two broad unequal lateral teeth. Upper subcoxa of Leg I-III with 1,1,4 chaetae, lower subcoxa with 1,6-7,7-8. Ti.I-III with one chaeta lost in basic set (20, 21,>25). Chaetae x and B5 on Ti. III in males unmodified. Distal tibiotarsal tenent chaetae on Ti.I-III (1-2-2) well developed, not clavate, about 1.1-1.2 as long as U.III. Each tibiotarsus with one additional tenent chaeta at middle part. Ti.III with one stick-like chaetae (A7) in distal ring, its shape slightly varies (Fig. 19). Tenent hairs (1,2,2) about 1.1-1.2 as long as U.III (Fig. 19). Pretarsus with two chaetae. Ventral tube with 4+4 laterodistal and 4 posterior chaetae in one transversal row. Tenaculum with 4+4 teeth and 1 chaeta. Anterior furcal subcoxa with 12-15 chaetae, posterior with 6 ones. Manubrium principally as in previous species. Dens slender, anteriorly normally with 11 chaetae. Posterior side of dens slightly crenulated in the medial part, with 5 chaetae of which 3 basal and 2 at the medial part (short inner and long outer) set together on low papillum. Mucro slender with two teeth of unequal size. Ratio of manubrium: dens: mucro = 3.2-3.6: 4.1-4.3: 1. Anal lobes without microchaetae.

Affinity.

See above for differences with Pauropygus projectus sp. n. After our study of type material of Cryptopygus riebi (South Africa) and two paratypes of Cryptopygus axayacatl (Mexico) we concluded that these species only complement the wide distribution area of Pauropygus caussaneli . Holotype and other paratypes of Cryptopygus axayacatl support its species status, but in the genus Proisotomodes .

Distribution.

Probably widely distributed on sandy seashores of tropics and subtro-pics. Recorded from the coast of Indian and Atlantic Oceans (Africa, Central America).