Ommatoiulus schubarti Akkari & Enghoff, 2012

Akkari, Nesrine & Enghoff, Henrik, 2012, Review of the genus Ommatoiulus in Andalusia, Spain (Diplopoda: Julida) with description of ten new species and notes on a remarkable gonopod structure, the fovea, Zootaxa 3538, pp. 1-53 : 41-45

Ommatoiulus schubarti Akkari & Enghoff n.sp.

Figs 90–93

Material. Holotype: 1 ♂ Andalusia, Granada, Collin leg. 1863 ( ZMUC) . Paratypes: 6 ♂, 16 ♀♀, 1 preadult ♀, 1 juvenile, same data as holotype ( ZMUC) .

Diagnosis. Most similar to Ommatoiulus fuscounilineatus ( Lucas, 1846) from North Africa ( Algeria, Tunisia) in the general shape of the gonopods, but differs in the shape of the apical part of the promerite, and the distal processes of the solenomerite.

Etymology. Species named in honour of Otto Schubart (1900–1962), an authority in millipede taxonomy who described several Ommatoiulus species from North Africa and looked at the type material of this species more than 80 years ago.

Description. Males: L: 26–30 mm, H: 2.0–2.5 mm, 47–51 PR+1–2 AR+T. Females: H: 2.7–3.0 mm, 48–52 PR+ 1–3 AR+T. Generally pallid after one and a half century in alcohol, but prozonites and posterior margin of metazonites obviously darker. Metazonites with regular striation, ozopores opening at a distance ca. their diameter behind suture, the latter complete, slightly curving at ozopore level. Telson: Preanal ring with a protruding caudal projection and a conspicuus upturned hyaline process; anal valves with a row of short setae on the margin, a submarginal row of longer ones and 1–3 setae on the surface; subanal scale setose triangular, pointed but not protruding, preanal ring with 3–4 setae on the tip.

Gonopods: Promerite (P) ( Figs 90, 92) with a broad mesal ridge (Mr) distally protruding into a subapical blunt, marginally serrated process, lateral margin (Lm) rounded, broadest at midlength with a deep supapical incision (in) separating it from the apical lobe (Al), the latter only slightly pointed; posterior surface with subapical rows of scattered setae near the lateral margin, rudimentary telopodite not very conspicuus. Posterior gonopods ( Figs 90–93): Mesomerite (Ms) broad in the proximal third, gradually narrowing distad, anterior margin angled and strongly curved at 2/3 of the process ( Figs 89, 90), distal part tapering and pointing posteriad. Solenomerite (S) simple with no accessory branches, broadest at the base, gradually narrowed in the distal third ( Figs 91, 92), apically consisting of a conical process (Cp1) with a pointed tip and a convoluted surface and a lamella bordered with strong spines, expanded in the lower margin in a rounded serrated hyaline process (H1) ( Fig. 93). Seminal groove (g) running mesoposteriad from the fovea (F), located at the base of the solenomerite ( Figs 89, 90) and opening at the tip of process Cp 1; paracoxite (Px) simple, of the same length as mesomerite, stout, rising from a broad coxa, curved mesad, apically slightly broadened with jagged surface ( Figs 92, 93).

Distribution. Known only from the type locality in Granada, Andalusia.

Comments. In 1931, Schubart looked at the type material, identified and labeled it as ‘ Archiulus cf. fuscounilineatus ’ suggesting a great resemblance of the new species with O. fuscounilineatus ( Lucas, 1846) . The latter species, described by Lucas (1846) from Algeria, was known to include several subspecies which were raised later to species level or synonymised with the nominal species (see Akkari et al. 2009), i.e., O. aumalensis ( Brolemann, 1925) described from Algeria, as well as O. seurati ( Brolemann, 1925) and O. fuscounilineatus denticulatus ( Attems, 1927) described from Tunisia. One of the most similar species in terms of gonopod structures is O. oxypygus (Brandt, 1841) , described from Sicily.

Having at our disposal samples from Tunisia of O. fuscounilineatus and O. seurati (from Aïn Draham, NW

Tunisia and Ichekeul National Park, N Tunisia, respectively, ZMUC) and O. oxypygus (from Sicily, ZMUC) we compared the structures of these three species with those of O. schubarti n. sp. using scanning electron microscopy

( Figs 94–102). These species share a number of structures: 1) Promerite gradually narrowing distally, apically with a more or less prominent rounded lobe, separated from a broad lateral margin by a subapical incision; a broad mesal ridge, apically protruding in a serrated process, a tuft of strong setae posteriorly near the mesal margin ( Figs 90, 94–96).

2) Mesomerite elongate, strongly bent at 2/3 length, tapering apically and pointing posteriad ( Figs 91, 97–99).

3) Solenomerite broad, without accessory branches, narrowing distally and apically with a conical process of varied length, containing the opening of the seminal groove, and a more or less simple jagged lamella ( Figs 91, 97–102).

4) Paracoxite stout, apically broadened and serrated, bent mesad ( Figs 100, 103–104).

As implicated by Schubart, the new species is most comparable with O. fuscounilinetaus , especially in the shape of the paracoxite but also in the apical part of the solenomerite consisting of a rounded lobe and a serrated conical process ( Figs 93, 102). On the other hand, the mesomerite is much more slender in O. schubarti , extending beyond the rest of the processes (like in O. seurati and O. oxypugus ) although not similarly curved. The promerite of O. schubarti is also clearly different from the three other species and stands out by the presence of a broader, laterally angular apical process and a deeper notch separting the latter from the mesal margin ( Fig. 90, Al) while the the apical process is uniformly rounded in fuscounilineatus , instead having a deep apical incision mesally ( Fig. 96). Moreover, while the mesal margin of the promerite is irregularly toothed apically in O. seurati and O. oxypugus ( Figs 94, 95), it is transformed into a slender apical, strongly jagged mesal process linked to the mesal margin by a serrated oblique lamella in fuscounilineatus ( Fig. 96) and to a blunt, short, weakly serrated process in O. schubarti ( Fig. 90, Bt).