Solentanodesmus insularis Antić & Reip, 2014

Antić, Dragan Ž., Reip, Hans S., Dražina, Tvrtko, Rađa, Tonći & Makarov, Slobodan E., 2014, Three new monotypic genera of Trichopolydesmidae from Croatia, Balkan Peninsula (Diplopoda, Polydesmida), Zootaxa 3884 (2), pp. 101-121 : 107-109

Solentanodesmus insularis Antić & Reip , sp. n.

Figs. 13–32

Material examined: Holotype male: Jama na Benkotovu Pit, Grohote, Island of Šolta, Croatia, 43.376°N, 16.272°E, 29.III.2012, leg. T. Rađa (IZB, VHD SI 100-5). Allotype female (IZB, VHD SI 100-6), paratype male I ( SMNG, VNR 016546-1), paratype female ( SMNG, VNR 016546-2) and paratype juvenile female (IZB, VHD SI 100-7): same data as holotype. Paratype male II: Stara Jametina Pit, Krka National Park, village of Konjevrate, near Drniš, Croatia, 43.789°N, 16.005°E, 15.XII.2012, leg. A. Čukušić (IZB, VHD SI 100-8). Paratype male III ( CBSS, DIP 336): same data as paratype male II. Further material: Golubinka pod Kraljevcom Pit, Radošić, Croatia, 43.596°N, 16.342°E, 07.V.2014, leg. T. Rađa, 2 males, 2 females, 1 juvenile female (IZB, VHD SI 100- 12).

Etymology: The species name insularis refers to the presence of this taxon on an island.

Description: Body with 19 segments (including telson) in adults (paratype juvenile female with 18 segments).

Measurements: holotype male 7.1 mm long, width of midbody pro- and metazonites (somite nine) 0.4 and 0.6 mm; allotype female 7.1 mm long, width of midbody pro- and metazonites (somite nine) 0.4 and 0.6 mm; paratype male I 7.2 mm long, width of midbody pro- and metazonites (somite nine) 0.4 and 0.6 mm; paratype female 7.1 mm long, width of midbody pro- and metazonites (somite nine) 0.5 and 0.6 mm, respectively.

Coloration: Body whitish, slightly translucent, with a visible gut. In some specimens, head and telson yellowish.

Head: Broader than collum, covered with numerous setae. Occipital suture distinct. Labrum with three labral teeth and eight labral and four supralabral setae. Promentum triangular, without setae. Lingual plates with 5+5 setae arranged in one row. Stipites with 16+16 setae. External palps with 5+5, medial palps with 7+7 (holotype male) or 8+8 (allotype female), internal palps with 3+3 papillae. Antennae in holotype male 1.1 mm long. Antennomeres II and III club-like, antennomeres IV, V, VI and VII subquadrate, especially three latter; antennomere VI: longest and thickest with a very thin base expanded abruptly. Antennomeres IV–VI with few long sensory setae; antennomere VII with one long sensory seta. Antennomere VI with a distodorsal pit with numerous bacilliform sensilla. Antennomere VII with a distodorsal knob with numerous setiform sensilla. Apical part of antennae with four large cones. Length/breadth ratios of antennomeres I–VII (holotype male): I (1.3), II (2.3), III (2.5), IV (1.7), V (1.6), VI (1.5), VII (1.3), respectively.

Collum: With a semi-circular anterior edge and an almost straight caudal margin. One caudal incision on lateral sides, with four irregular transverse rows of setae; setal formula (holotype male): 8+8+8+12.

Body segments: Segments II–IV with four irregular transverse rows of medium-sized trichoid setae on minute tubercles. Segments V and VI with five rows of setae; VII–XIII with six rows of setae while XIV–XVIII with six or seven rows, last row on each segment being best-expressed and carrying the largest number of setae. Pleurosternal carinae with well-developed triangular teeth present on each side of segments II–XVII. Apodous (XVIII) segment without pleurosternal carinae. Number of teeth in holotype male: segment II: with five larger and two smaller teeth; III and IV (6/6); segments V–XII (8–9); segments XIII–XV (9–10); segment XVI (11/11); XVII (10/10), respectively. In allotype female: II (3/4), III and IV (5/6), V (9/9), VI (8/7), VII and VIII (9/8), IX (8/7), X (10/8), XI and XII (8/8), XIII (8/10), XIV (8/9), XV and XVI (9/10), and XVII (8/9), respectively. Prozonite slightly punctate. Stricture visible. Paraterga with four dorsolaterally positioned, laterally directed cones. Each cone bearing one seta, except last one on poriferous metazonites, enlarged and bearing an ozopore and three medium-sized setae, also containing a reactivation chamber of the defense mechanism. Pore formula normal: V, VII, IX, X, XII, XIII, XV–XVIII. Epiproct subtriangular in dorsal view, directed caudoventrally, tip with four spinnerets. Paraprocts semi-circular, each with two setae. Hypoproct subtrapeziform, with two long paramedian setae. Sterna unmodified, poorly setose. Epigynal ridge low and simple.

Walking legs: Long and slender, without modified setae. Femora and tarsi elongated, claws medium-sized.

Gonopods: Gonopod aperture transverse-oval, taking up slightly less than half of ventral part of metazonite VII. Gonocoxae rounded, with two lateral setae and one mesal seta. Cannula absent. Prefemoral part (pf) massive, held transversely to body axis; covered with numerous setae. Border between prefemoral part and acropodite (a) with a long and slender process (sp). Acropodite long and thin, directed frontally, divisible into two parts. Basal part convex, with or without a short triangular tooth (tt) in the middle, also with a long, thin, finely denticulate and slightly curved process (cp) above tt. Apical part of acropodite represented by a very long, simple, thin, curved, flagelliform process (fp). Both fp crossing or almost crossing medially in situ. Solenomere absent, seminal canal opening at border between cp and fp, surrounded by fine lamellae (l).

Habitat: The Jama na Benkotovu Pit is 35 m deep. The mean temperature in the cave is 10°C. All four specimens were collected at a depth of about 30 m, 30 cm deep under stones (not on the surface itself).

The Stara Jametina Pit is 85 m deep and 188 m long, with a mean temperature of 12°C. All specimens were collected in the deepest part of the pit, also under stones. Other notable troglobitic species found in this part of the pit are Zospeum isselianum Pollonera, 1887 (Gastropoda) , Chthonius (Microchthonius) rogatus Beier, 1938 (Pseudoscorpiones) , Stalagtia hercegovinensis (Nosek, 1905) (Araneae) , Alpioniscus balthasari Frankenberger, 1937 (Isopoda) , Troglopedetes pallidus Absolon, 1907 and Verhoeffiella sp. ( Collembola ) ( Marguš et al. 2012).

The Golubinka pod Kraljevcom Pit is about 25 m deep and about 30 m long, with a mean temperature of 10°C. The entrance to the cave lies at an altitude of 256 m. The specimens were found in the dark part under stones at the edge of an old pigeon guano dropping.

Figures

FIGURES 13 – 16. Solentanodesmus insularis gen. n., sp. n., paratype male. 13: habitus, dorsal view, 14: habitus, lateral view, 15: head and first six segments, lateral view, 16: body end, lateral view. Scale line: 1 mm (13 – 14) and 0.5 mm (15 – 16).

FIGURE 17. Solentanodesmus insularis gen. n., sp. n., male. Head and first six segments, lateral view.

FIGURE 18 – 23. Solentanodesmus insularis gen. n., sp. n., male. 18: segments XIII and XIV, lateral view, 19: segment VII, paratergal cones and pleurosternal carina, lateral view, 20: segment VII, gonopod aperture and pleurosternal carina, ventral view, 21: triangular teeth of pleurosternal carina, ventral view, 22: segment IX, dorsal view, 23: body end, lateral view.

FIGURES 24 – 26. Solentanodesmus insularis gen. n., sp. n., male. 24: antennomeres VI – VIII, 25: distodorsal pit of antennomere VI, 26: sensitive seta and distodorsal knob with sensillae of antennomere VII.

FIGURE 27 – 28. Solentanodesmus insularis gen. n., sp. n., paratype male gonopods. 27: lateral view, 28: in situ. Scale line: 0.1 mm.

FIGURES 29 – 32. Solentanodesmus insularis gen. n., sp. n., holotype male gonopod. 29 – 30: lateral view, 31: mesal view, 32: ventral view. Designations: a: acropodite, l: lamella, cp: slightly curved process, fp: flagelliform process, pf: prefemoral part, sp: slender process, tt: triangular tooth. Scale line: 0.2 mm.