Sphaeroparia simplex, Golovatch, Sergei I., 2013

Golovatch, Sergei I., 2013, A reclassification of the millipede superfamily Trichopolydesmoidea, with descriptions of two new species from the Aegean region (Diplopoda, Polydesmida), ZooKeys 340, pp. 63-78 : 67-71

Sphaeroparia simplex sp. n. Figs 7-17

Type material.

Holotype ♂ (NMNHS), Greece, Kithnos Island, village Dryopis near Phirès, Cave Katafyki, 08.05.1987, leg. P. Beron.

Paratypes: 1 ♂, 4 ♀♀, 1 ♂ subadult (19 body segments), 2 fragments (NMNHS) + 1 ♂, 1 ♀ (ZMUM), same locality, together with holotype; 1 ♂, 1 ♀, 1 ♀ fragment (head and first 12 body segments) (NMNHS), Greece, Chios Island, village Haghios Galos (Agiongalas, Haghia Gala), 65 km from town of Chios, Cave Hagiogalousaina , 12.05.1987, leg. P. Beron.

Diagnosis.

Differs from the other 30+ species of Sphaeroparia Attems, 1909, many of which have been reviewed by Mauriès and Heymer (1996), by 20 body segments in both sexes and the presence of an axial sternal process on the especially simple gonopods, including a nearly fully suppressed solenomere.

Name.

To emphasize the highly simple gonopods in this species.

Description.

Length of adults ca 5.0-5.5 (♂) or 6.0-7.0 mm (♀), width of midbody pro- and metazona 0.55 and 0.7 mm (♂, ♀), respectively. Coloration in alcohol uniformly pallid to light yellowish (Figs 7-10).

Body with 20 segments in both sexes. Tegument generally smooth, dull, texture very delicately alveolate. Head densely pilose throughout; ♂ epicranial modifications absent, frons being regularly convex in both sexes. Antennae rather short and clavate, nearly reaching end of segment 2 (♂) or collum (♀) when stretched dorsally; antennomeres 2, 3, 5 and 6 subequal in length, but both 5th and 6th clearly the highest (height being measured from ventral to dorsal side) (Figs 11, 15); antennomeres 4-6 each with a loose, indistinct, distodorsal group of increasingly long and numerous sensilla.

In width, head = segments 6-16(17)> 5> 4> 2 = 3> collum; starting from segment 17, body gradually tapering towards telson. Collum ellipsoid, lobuliform caudolaterally, like most of following metaterga with 3 transverse, rather regular rows of 3+3 setae on minute knobs until segment 16, of 4+4 setae in segments 17(18)-19. Tergal setae medium-sized, slender, bacilliform, mostly about 1/4 the length of a metatergum, a little longer only on collum and penultimate segment. Usually a very faint transverse sulcus between first 2 rows of setae. Dorsum invariably convex. Paraterga poorly developed, especially so in ♀, visible starting from collum, invariably slightly declivous, set rather high (mainly at about upper third of midbody height in both sexes), slightly, but regularly rounded laterally; lateral margin of postcollum paraterga very poorly indentate, on each side usually with 3 subequal setigerous indentations in front of a rounded caudolateral lobule, the latter increasingly well drawn caudad, but never extending behind rear tergal margin (Figs 7-10). Pore formula normal: 5, 7, 9, 10, 12, 13, 15-18(19), ozopores round, dorsal, rather indistinct, lying at base of caudolateral lobule near lateral margin. Stricture between pro- and metazona wide, shallow and smooth. Limbus very finely microspiculate. Epiproct conical, rather long. Hypoproct trapeziform.

Sterna clearly separated, unmodified. Legs rather long and slender (Figs 8, 10, 12, 16), without modified setae, ca 1.2-1.3 (♂) or 1.0-1.1 (♀) times as long as midbody height, tarsi longest, claw short. Epigynal ridge very low, inconspicuous.

Gonopod aperture evident, transversely oblong-oval, taking up most of ventral part of metazonite 7. Gonopods (Figs 12-14, 17) with large, transversely subglobose, evidently exposed, medially fused, medially clearly excavate coxites, each microgranular/scaly and micropilose laterally, carrying only 1 long seta distofrontally and a long, curved cannula distomesally; sternum plate-like, with a slender, central, not too strongly chitinized process (k) between coxites. Telopodites short, stout, subglobose, sac-shaped, very simple, only moderately exposed below coxites, deeply sunken inside a prominent gonocoel; prefemoral part as usual, setose, quite elongate, about as long as, but clearly set at an angle to, acropodite, the latter with a distinct seminal groove running entirely on mesal side and terminating on a vestigial lobuliform solenomere (sl) at base of a rather strong, only faintly curved, apical spine (d). Neither an accessory seminal chamber nor a hairy pulvillus.

Remarks.

This species seems to be only a troglophile, which occurs in caves on two remote islands in the Aegean Sea. On the other hand, Cave Katafyki is known to support at least two presumed troglobites, i.e. the woodlouse Cordioniscus kithnosi Andreev, 1986 ( Isopoda , Oniscidea , Styloniscidae ) ( Schmalfuss 2003) and the millipede Syrioiulus andreevi Mauriès, 1984 ( Diplopoda , Julida , Julidae ) ( Mauriès 1984), while Cave Hagiogalousaina hosts the presumed troglobitic false-scorpion Chthonius chius Schawaller, 1990 ( Pseudoscorpiones , Chthoniidae ) ( Harvey 2008) and the millipede Hyleoglomeris subreducta Golovatch, 2013 ( Diplopoda , Glomerida , Glomeridae ) ( Golovatch in press).

The discovery of a Sphaeroparia in the Aegean region is even more remarkable than that of a Galliocookia . Indeed, Sphaeroparia is a rather large genus hitherto believed to be strictly Afrotropical, ranging from Liberia and Benin in western Africa, through Gabon and Zaire, to Kenya and Tanzania in eastern Africa (see review by Mauriès and Heymer 1996). Furthermore, it has been assigned to the large pantropical family Fuhrmannodesmidae ( Hoffman 1980, Mauriès and Heymer 1996), as opposed to the Holarctic Macrosternodesmidae , the Nearctic Nearctodesmidae (often referred to as only a subfamily of Macrosternodesmidae ), and the Euro-Mediterranean Trichopolydesmidae . The Fuhrmannodesmidae has long been considered as an artificial, composite group (e.g. Hoffman 1980, Mauriès and Heymer 1996, Golovatch et al. 2013), being distinguished from the above allies solely by its being tropical.

Golovatch (1994) provided an evolutionary scenario for the genera of Fuhrmannodesmidae known from South America, accepting as the basalmost those genera showing rather small, subglobose gonopod coxae that form no significant gonocoel in which to hinge the largely exposed, usually rather simple and elongate telopodites. Moreover, as in some true Trichopolydesmidae (see above), the prefemoral (= setose) part of the gonopod is mostly orientated transversely to the body axis, extending mesally across the entire width of the coxae. Following a series of transitional states, such forms ultimately culminate in having the gonopod coxae strongly enlarged, forming a large gonocoel in which to conceal the clearly shortened, usually highly complex and deeply sunken telopodites. Their prefemoral parts already tend to be positioned increasingly parallel to the body’s main axis, thus providing a transition between the usually small-sized Trichopolydesmoidea (= so-called “micropolydesmoids”) to the normally medium- to large-sized Polydesmoidea (= so-called “macropolydesmoids”).

Naturally, similar general trends can be surmised to have occurred in the fuhrmannodesmids of Central America and the Afrotropical and Oriental realms, which also support fairly diverse faunas of this family. Remarkably, none of the genera of Trichopolydesmidae (see above), all confined to Europe and the Mediterranean, though demonstrating a certain degree of variation in the length and orientation of the gonopod prefemoral part, has a deep gonocoel. Furthermore, Galliocookia as one of the few genera where the gonocoxae are particularly small while the prefemoral part is still elongate, but already strictly coaxial with a very strongly exposed acropodite represents an evolutionary extreme, apparently the basalmost situation. The discovery of a Sphaeroparia in the eastern Mediterranean, of an Afrotropical genus demonstrating a very large and deep gonocoel for the small and only poorly exposed telopodites to be hinged into, clearly represents the opposite, evolutionarily obviously the most advanced extreme. Therefore, the Euro-Mediterranean Trichopolydesmoidea appear to show basically the same full range of evolutionary trends in the development of gonopod structures as do at least the properly assessed South American representatives now assigned to Fuhrmannodesmidae ! Among the Afrotropical Trichopolydesmoidea , Sphaeroparia is certainly the most speciose genus and Mauriès and Heymer (1996) divide it into as many as six subgenera, most of which they themselves admit to be ill-grounded. A Sphaeroparia species is likely to be present also in the Seychelles ( Golovatch and Gerlach 2010). In contrast to the Euro-Mediterranean region, the Afrotropical realm is thus dominated by trichopolydesmoids showing a deep gonocoel between strongly hypertrophied gonopod coxae. Only Peronorchus parvicollis Attems, 1907, the type and still sole species of Peronorchus Attems, 1907, shows a far more basal gonopod structure quite comparable to that of Trichopolydesmus . That species was originally described from near Buitenzorg (= Bogor), Java, Indonesia, and it has since been redescribed from material from Mauritius, Indian Ocean and formally assigned to the family Trichopolydesmidae ( Mauriès and Geoffroy 1999). However, Peronorchus has recently been transferred to Fuhrmannodesmidae ( Golovatch et al. 2013).

Considering the above new evidence, I no longer hesitate to formally synonymize the family Fuhrmannodesmidae Brölemann, 1916 under Trichopolydesmidae Verhoeff, 1910, syn. n.