Rhodopodesmus niveus gen. nov. et, 2022

Antic, Dragan, Vagalinski, Boyan, Stoev, Pavel & Akkari, Nesrine, 2022, A review of the cavernicolous Trichopolydesmidae (Diplopoda, Polydesmida) from the Carpathian-Balkan arch and the Rhodope Mountains, with descriptions of two new genera and three new species, ZooKeys 1097, pp. 1-46 : 1

publication ID	https://dx.doi.org/10.3897/zookeys.1097.83916
publication LSID	lsid:zoobank.org:pub:66F17436-DF36-4FFD-B2D3-021F14D40D62
persistent identifier	https://treatment.plazi.org/id/CC18A689-89BD-4197-922D-9CB3D8B3EA77
taxon LSID	lsid:zoobank.org:act:CC18A689-89BD-4197-922D-9CB3D8B3EA77
treatment provided by	ZooKeys by Pensoft
scientific name	Rhodopodesmus niveus gen. nov. et
status	sp. nov.

Treatment

Rhodopodesmus niveus gen. nov. et View in CoL sp. nov.

Figs 14 View Figure 14 , 15 View Figure 15 , 16 View Figure 16 , 17K View Figure 17 , 18 View Figure 18

Bacillidesmus sp. nov.- Vagalinski and Stoev 2011: 135.

Bacillidesmus sp. [nov.]- Beron 2015: 80.

Diagnosis.

As for the monospecific genus.

Name.

The specific name is a Latin adjective; niveus refers to the snow-white body color of the living specimens. Furthermore, the name of the type locality, cave Snezhanka, in Bulgarian means Snow White, the heroine from the fairy tale of the Brothers Grimm.

Material examined.

Holotype ♂ (NMNHS-10823), Bulgaria, Pazardzhik District, Peshtera Municipality, Peshtera, Snezhanka Cave , N 42.00222, E 24.27764, 26.X.2020, leg. D. Antić & B. Vagalinski. GoogleMaps

Paratypes. 3 ♀♀ (one used for SEM, NMNHS-10824-10826), same data as for holotype GoogleMaps ; 1 ♀ (used for SEM, NHMW MY10259) same data as for holotype GoogleMaps .

Additional material.

1 ♂ (fragments, one gonopod available, NMNHS-10827), 1 ♀ (fragments, NMNHS-10828), both fragments, 1 whole juvenile (NMNHS-10829), same cave but 18.IX.2005, leg. P. Beron.

Description.

Number of body rings and measurements: Body with 19 rings (including telson) in adults, moniliform (Fig. 14 View Figure 14 ). Holotype male 5.3 mm long, width of midbody pro- and metazonae 0.35 mm and 0.50 mm, respectively. Paratype females 4.3-5.4 mm long, width of midbody pro- and metazonae 0.35-0.40 mm and 0.45-0.60 mm, respectively.

Coloration: Living animals snow white (Fig. 14A View Figure 14 ), slightly translucent. Yellowish in alcohol (Fig. 14B-E View Figure 14 ).

Head: Broader than collum, setose; epicranial suture poorly developed; isthmus between antennae ≈ 1.7 × broader than diameter of antennal socket (Fig. 15A, D View Figure 15 ). Labrum with three labral teeth, and with 3+3 labral and five supralabral setae (Fig. 15A View Figure 15 ). Gnathochilarium without peculiarities. Antennae rather short, clavate (Figs 14A, C View Figure 14 , 15B, C View Figure 15 ). Antennomere length 6> 2 = 3 = 4> 5> 7 = 1. Antennae 0.8 mm long in holotype male; length/breadth ratios of antennomeres 1-7: 1 (1), 2 (2), 3 (2), 4 (2), 5 (1), 6 (1.5) and 7 (1). Antennomere 6 with four sensilla trichodea and with strongly developed disto-dorsal pit with numerous long sensilla basiconica partially exposed outside the pit (Fig. 15C View Figure 15 ). Antennomere 7 with one sensillum trichoideum and a small bulge with three sensilla basiconica spiniformia (Fig. 15B, C View Figure 15 ). Four apical cones (Fig. 15C View Figure 15 ).

Collum: Semi-circular, with one or two lateral incisions and ≈ 6 irregular rows of medium sized and trichoid setae (Fig. 15D, F View Figure 15 ).

Body rings: Tegument shining, texture alveolate, reticulate and scaly. Rings densely setose (Fig. 14B-E View Figure 14 ). Setae medium sized and trichoid, originating from small tubercules (Fig. 15D-F, H-J View Figure 15 ). Posteriormost tubercules mostly with a small thorn (Fig. 15E View Figure 15 ). Rings 2-4 with ≈ 4 rows of setae (Fig. 15D, F View Figure 15 ). Rings 5-18 with ≈ 6-8 irregular rows of setae (Fig. 15D-F, H-J View Figure 15 ). Paraterga serrated, with 5-7 teeth (Fig. 15E, H View Figure 15 ). Pore formula normal: 5, 7, 9, 10, 12, 13, 15-18. Poriferous metazonae with enlarged posterolateral cone bearing an ozopore and three medium-sized setae (Fig. 15G View Figure 15 ). Epiproct triangular in dorsal view, directed slightly caudoventrad (Fig. 15H, I View Figure 15 ). Paraprocts semi-spherical, each with two long setae originating from small tubercules and ≈ 10 shorter setae without tubercules (Fig. 15I View Figure 15 ). Hypoproct trapeziform, with two long distal setae and numerous shorter setae throughout (Fig. 15I View Figure 15 ). Sterna unmodified, poorly setose. Pleurosternal carinae absent, only a few small teeth present on rings 2 and 3 (Fig. 15F View Figure 15 ). Gonopod aperture large, subsemi-circular.

Walking legs: Legs 1-3 in males with swollen femur, especially femur 2; coxa 2 with a short mesal apophysis (cf. Strasser 1966a: 341, fig. 13). No other peculiarities.

Gonopods (Figs 16 View Figure 16 , 17K View Figure 17 ): Coxa (cx) large, semi-circular in ventral view, with deep gonocoel mesally; anterior third much lower than rest of coxa, shield-like, thus lateral, swollen and alveolate part rectangular in lateral view; with ≈ 15 setae. Cannula (ca) long, C-shaped. Telopodite long compared to coxa, consisting of a transverse, setose prefemorite (pf) and more or less C-shaped (in lateral and mesal views) acropodite (a) longitudinally divided in distal half into two branches, solenomeral branch (sb) and solenophore (sph). Solenomeral branch positioned mesally, transversely divided into three processes, besides solenomere (s) and distal solenomeral process (dsp), there is an additional, proximal solenomeral process (psp), more or less spatulate and forming C-shaped rift with solenomere. Both solenomere (s) and distal solenomeral process (dsp) long, slender, of same length, forming acute angle at bifurcation. Solenophore (sph) longer than solenomeral branch, characterized by a lateral lamella (ll) and a distal projection (dp). Lateral lamella (ll) with triangular lobe. Distal projection (dp) long, thin and twisted. Seminal groove (sg) starts from seminal fossa (sf) mesally on prefemorite, extends along mesal side of acropodite up to bifurcation of solenomeral branch and solenophore, then passes on lateral side of solenomeral branch, further proximally on solenomere, ending distally.

Habitat.

Snezhanka Cave consists of a single gallery forming six distinct halls with total length of 348 m. The entrance is located at 865 m a.s.l. The cave is rich in diverse sinter formations and sinter ponds. It was established as a natural monument in 1961, and has served as show cave since 1968 ( Petrov and Stoev 2007). Most of the cave’s invertebrate fauna known at present includes either trogloxenes or troglophiles ( Beron 2015), with the exception of the local endemic Paralovricia beroni Giachino, Guéorguiev & Vailati, 2011 ( Coleoptera , Carabidae ), which is considered a probable hypogean, although not typical troglobitic species ( Giachino et al. 2011). Another myriapod known from this cave is Lithobius lakatnicensis Verhoeff, 1926.

All five recently collected specimens of Rhodopodesmus niveus gen. nov. et sp. nov. by D.A. and B.V. were found in the middle part of the cave at two spots, and all were in rotten wood.

Distribution.

So far, known only from its type locality, the Snezhanka Cave, Bulgaria (see also under Remarks) (Fig. 18 View Figure 18 ).

Remarks.

As mentioned above, it seems that the most similar genus to Rhodopodsemus gen. nov. is Balkanodesminus gen. nov., which makes sense due to their distributions. These two genera share not only similarities in certain habitus features but also in the gonopods. Both include small-bodied species with 19 rings in adults, with sensilla basiconica on antennomere 6 partially exposed outside the pit, hypoproct with more than two long distal setae and paraprocts with more than 2+2 long setae. The conformation of the gonopods is very similar, where the acropodite is longitudinally divided into two branches, with the solenomeral branch transversely divided into long and relatively slender solenomere and well-developed distal process in both genera. Based on this, both genera differ from other European Trichopolydesmidae . However, in Rhodopodesmus gen. nov. the solenomeral branch is trifid, where in addition to solenomere and distal process, in the base of this branch there is another, proximal process, which is more or less spatulate. These two genera also differ in some details of the gonopod coxa. Rhodopodesmus gen. nov. has a very deep gonocoel, i.e., the anterior third of the coxa is much lower than the rest it, in the form of a shield, so that the rest of the coxa has a more or less rectangular shape laterally, while in Balkanodesminus gen. nov. it is semi-circular. Also, the coxa in Rhodopodesmus gen. nov. has circa 15 setae, while the same in species of Balkanodesminus gen. nov. bears only 3.

It is worth mentioning that specimens of Rhodopodesmus gen. nov. were found in two more caves in the Rhodopes, viz., one female in Dupkata (= Dupcheto) Cave near Rakitovo and one male and one female in Skoka Cave near Ribnovo. Unfortunately, the material from Skoka Cave (including one male) could not be relocated in NMNHS for this study, and we still do not know whether it is R. niveus gen. nov. et sp. nov. or a new species. The female from Dupkata Cave probably belongs to R. niveus gen. nov. et sp. nov. considering its proximity to the type locality of this species. Both localities are mapped (Fig. 18 View Figure 18 , yellow squares), and already noted under Bacillidesmus sp. nov. by Vagalinski and Stoev (2011).