Stygiiulus ausugi (Manfredi, 1953) Vagalinski & Borissov & Bobeva & Canciani & Antić, 2022

Vagalinski, Boyan, Borissov, Simeon, Bobeva, Aneliya, Canciani, Giacomo & Antić, Dragan Ž., 2022, The mostly cavernicolous millipede genus Stygiiulus Verhoeff, 1929, stat. nov.: taxonomy, distribution and phylogenetic relationships (Diplopoda, Julida, Julidae), European Journal of Taxonomy 798, pp. 30-69 : 34-35

Stygiiulus ausugi (Manfredi, 1953) comb. nov.

Figs 10A , 11A , 13

Typhloiulus ausugi Manfredi, 1953b: 136–138 , figs 1–2.

Typhloiulus (Stygiiulus) ausugi – Strasser 1962: 11, 12, 18, 37, 38, figs 1–2, 8, 11h, 15, 41–44.

Typhloiulus (Stygiiulus) ausugi ausugi – Strasser 1971a: 13.

Typhloiulus ausugi ausugi – Minelli 1985: 9.

Typhloiulus ausugi – Vagalinski et al. 2015: 336–337 .

Diagnosis

One of the three species of Stygiiulus stat. nov. with modified mouthparts, the other two being S. fimbriatus comb. et stat. nov. and S. gentianae comb. et stat. nov. Differs from both mainly by the complete absence of posterior hump on opisthomere, the very large velum with minute fringes on posterodistal margin, and the anterior and posterior solenomeral branches both being very short, hardly distinguishable.

Material examined

ITALY – Trentino (Autonomous Province of Trento) • 1 ♂; topotype; Altopiano dei Sette Comuni , Grigno , Grotta [Cave] della Bigonda (243 VT/TN); 450 m a.s.l.; 10 Mar. 1996; G. Peretto and E. Piva leg.; H. Enghoff det. 2013; NHMD • 1 ♀; Grigno, Grotta [Cave] del Calgeron (new record), a side branch of the waterfall; Dec. 1973; Ischia leg.; H. Enghoff det. 1984; A. Minelli ded. 1985; NHMD .

Descriptive notes

ANTENNAE. 2–2.1 times as long as head and 1.7–1.75 times as long as H in males, and 1.7–1.8 times and ca 1.4 times, respectively, in females; antennomere 5 ca twice as long as broad; antennomeres 2, 3 and 4 subequal in length, ca 1.2 times as long as 5, and 1.7–1.8 times as long as 6; 6 visibly broader than 5, giving a clavate appearance of the antenna.

MOUTHPARTS. With strong hydrophilous modifications (sensu Enghoff 1985): labrum edentate or with three minute, vestigial teeth. Gnathochilarium short and distally markedly broad, stipites with conspicuously large palps. Gnathal lobes of mandibles with the external and the internal tooth strongly reduced, both being distinct but very small and pointed, deeply hidden in the buccal cavity; molar plate much smaller than the normal julid condition; pectinate lamellae five instead of the usual four, consisting of very fine and densely set teeth.

TARSUS OF MID- BODY LEGS. Ca 2.5 times as long as tibia and ca 5 times as long as apical claw. Mid-body legs ca 1.7 times as long as H in males and ca 1.4 times in females.

FEMALE SEXUAL CHARACTERS. Legs 1 and 2 slightly shorter but not thicker than following legs. Vulva ( Fig. 11A ) symmetric; bursa very broad, strongly compressed in the sagittal plane; each valve of bursa with one vertical row of setae; operculum (op) distally bulging, with a distinct apical concavity, exceeding bursa by nearly ⅓ of total height of vulva, with just several setae each side. Receptaculum seminis consisting of two small tubes: a very fine, somewhat bent, mesal one (mt) ending in a small ovoid ampulla (ma), and a significantly broader, mostly straight, lateral one (lt), not forming ampulla at bottom.

Distribution

Prior to this study, the species was known only from its type locality – the Grotta della Bigonda – on the northern border of the central part of the Venetian Prealps. The new locality of this species – the Grotta del Calgeron – is located in the same area, some 20 km south of the type locality ( Fig. 13 , blue circles).

Remarks

Strasser (1971a) described two subspecies of ausugi , viz., fimbriatus and gentianae . Considering the gonopod conformations of the two latter forms, both of which differ significantly from S. ausugi comb. nov. and are instead much more similar to S. illyricus comb. nov., S. maximus comb. nov., S. montellensis comb. nov., and S. rotundatus comb. et stat. nov., it becomes obvious that Strasser (1971a) treated the modified mouthparts as a taxonomic feature of primary importance, being unaware of the adaptive nature of such modifications, as revealed later by Enghoff (1985). Thus we here elevate fimbriatus and gentianae to the species level and describe both of them in detail below.

In the Grotta della Bigonda, this species lives in sympatry with S. tobias comb. nov.

Figures

Fig. 10. Left gonopods of species of Stygiiulus stat. nov., mesal views. A. S. ausugi (Manfredi, 1953) comb.nov.,topotype♂(NHMD).B.S.illyricus(Verhoeff,1929)comb.nov.,redrawnfromVerhoeff (1929). C. S. insularis (Strasser, 1938) comb. nov., redrawn from Antić et al. (2018). D. S. maximus (Verhoeff, 1929) comb. nov., redrawn from Verhoeff (1930). E. S. seewaldi (Strasser, 1967) comb. nov., redrawn and modified from Strasser (1967). F. S. tobias (Berlese, 1886) comb. nov., ♂ from Grotta [Cave] del Subiolo (NHMD). Abbreviations: do = distal outgrowth of velum. Drawn not to scale.

Fig. 11. Left vulvae of species of Stygiiulus stat. nov. (A–D) and representatives of (other) Julini/ Leptoiulini (E) and Typhloiulini/blind Julini/Leptoiulini in caudal, somewhat mesal views. A. S. ausugi (Manfredi, 1953) comb. nov., ♀ from Grotta [Cave] del Calgeron (NHMD). B. S. illyricus (Verhoef, 1929) comb. nov., ♀ from Rabakova Cave (IZB). C. S. insularis (Strasser, 1938) comb. nov., topotype ♀ (CBSS). D. S. tobias (Berlese, 1886) comb. nov., ♀ from Grotta [Cave] del Subiolo (NHMD). E. Leptoiulus cf. trilineatus(C.L. Koch, 1847), ♀ from Belasitsa Mtn, Bulgaria. F. Serboiulus spelaeophilus Gulička, 1967, ♀ from Vodni Pech Cave (NMNHS). G. Typhloiulus (Inversotyphlus) lobifer Attems, 1951, ♀ from Minjera-Bauxite Mine (IBER). H. Typhloiulus (s. str.) strictus (Latzel, 1882), ♀ from Kunino (IBER). Abbreviations: at = anterior tube; la = lateral ampulla; lt = lateral tube; ma = median ampulla; mt = median tube; op = operculum; pa = posterior ampulla; pt = posterior tube. Scale bar = 0.2 mm.

Fig. 13. General distribution of the species of the genus Stygiiulus stat. nov.