Domitius, Ribera, 2018

Ribera, Carles, 2018, A new genus of nesticid spiders from western European Peninsulas (Araneae, Nesticidae), Zootaxa 4407 (2), pp. 229-240 : 233-238

Domitius new genus

( Figs 2 A–F , 3 A–F , 4 A–F , 5 A–C )

Type species. Nesticus baeticus López-Pancorbo & Ribera, 2011

Material examined. D. baeticus : Holotype ♂ (1619-A25) Cueva de la Murcielaguina , Hornos, Jaén, Spain, 5-XI- 2006, GEV leg . Paratypes: 2♀♀ (1619-A25) same locality and data. D. murgis : Holotype 1 ♂ (3596/143) Sima Termal , Sierra de Gádor , El Ejido, Almería, Spain, 5-III-00, M. Piquer, J. G. Pardo Leg . Paratypes: 1 ♂ (3600/ 143), 12 ♀♀ (3592, 3595, 3599, 3601, 3603/143) same locality and data. D. luquei : Holotype 1 ♂ (2398/96) Cueva del Hayal , Merodio, Peñamelera Baja, Cantabria, Spain, 17-XII-1993, C. Gonzalez-Luque Leg . Paratypes: 1 ♀ (2400/96) same locality and data ; 1 ♂ (2402/97), 3 ♀♀ (2403/97) Cueva de la Roguería , Oreña, Cantabria, Spain, 2-IV-1994, C. Gonzalez-Luque Leg. D. lusitanicus: Topotypes : 1 ♂ (SR-1), 8 ♀♀ (SR-15), Algar do Ladoeiro , Alvados, Porto de Moz, Portugal, 1-VI-2007, Sofia Reboleira Leg. ; 1 ♂, 2 ♀♀, 17-III-2007, same locality. D. sbordonii . Holotype 1 ♂ Grotta della Croce , Frosinone, Supino, Lazio, Italy, 1-XI-1977, V. Sbordoni leg.; Paratype : 1♀, same locality, 8-II-1976, V. Sbordoni leg. D. menozzi. Topotypes : 1♂, 1♀ Grotta della Volpe Liguria , Genova, Italy, 23.XI.1969, A Vigna leg.; Other material examined : 1♂. Grotta delle Fate , Liguria, 30.XI.1971, Gardini leg.; D. speluncarum . Topotypes : 2 ♂♂ 1 ♀, Grotta Bocca Lupara , La Spezia, Liguria, Italy, 5-III- 1 969, P. Bringoli det. (the female from Brignoli’s collection had the genital organs removed and lost).

The Iberian specimens are deposited in the Arachnid Collection of the Centre de Recursos de Biodiversitat Animal at the University of Barcelona, spain (collection number in brackets). The Italian specimens examined ( D. sbordonii , D. menozzi and D. speluncarum ) come from the collections of Museo Civico di Storia Naturale, Verona, Italy.

Etymology: The generic name is a patronym in honor of Gnaeus Domitius Ahenobarbus, proconsul of Rome who built the Via Domitia in 118 BC, the first Roman road that linked Italy and Hispania. Gender masculine.

Diagnosis. Domitius n. gen. differs from other nesticid genera by the morphology of both male and female copulatory organs. In males the median apophysis is absent or poorly developed, in this case it is reduced to a hardly visible small inconspicuous fingerlike process fused to the tegulum ( D. baeticus: Lopez-Pancorbo & Ribera 2011 , p 6 Fig. 5 , and D. lusitanicus ). Males of Domitius n. gen. can also be distinguished from those of other nesticid genera by the shape, ramification and modifications associated to the paracymbium. Males of the new genus show a large paracymbium with well-developed ventral and dorsal processes ( Figs 2 A–F , 5 A–C ). In females ( Fig. 4 A–F ) spermathecae are located in the middle-lower part of both sides of the vulva. On the basis of these morphological characters the new genus differs clearly from the European genera Cryptonesticus, Aituaria , Nesticus and Carpathonesticus , males of which shows a very conspicuous median apophysis. The most morphologically similar genus is Typhlonesticus but this shows the paracymbium short and the dorsal and ventral processes scarcely developed ( Deeleman-Reinhold 1974 Figs 2–3 ; Ribera el al. 2014 Figs 14–17). Domitius n. gen. can also be distinguished from Typhlonesticus by the size and position of the tegulum and by TTA processes. In Typhlonesticus the tegulum is very prominent, consisting of a ventrally directed triangular apophysis and the TTA shows the p1 and p2 processes highly developed and directed also ventrally. In Domitius n. gen. the tegulum is not prominent and the TTA p1 and p2 processes, although directed ventrally are not so developed. In Typhlonesticus females the insemination ducts are coiled forming, at least, two laps around the fertilization duct before reaching the spermatheca, and the vulval pockets are absent ( Deltshev et al. 2014 Figs 7–8; Deeleman-Reinhold 1974 Fig. 7). In Domitius n. gen. the vulva shows the insemination ducts slightly curved towards both sides but never coiled and the vulval pockets are always present ( Fig. 4 A–F ).

Description: Small to medium sized nesticids (males 2.6–6.4; females 3–6.5 mm). Coloration variable: prosoma from whitish or yellowish to grayish. Abdomen uniformly pale yellowish, whitish or grayish, may show clearly marked darker patches according to the degree of adaptation to the underground environment ( D. luquei ).

Carapace approximately circular in dorsal view. Cephalic region not raised but differentiated from the rest of the carapace. Fovea and thoracic grooves clearly visible. Eyes from well-developed to totally absent in troglobiomorf species: well-developed and slightly depigmented ( D. luquei ), markedly reduced ( D. menozzii , D. sbordonii , D. speluncarum ( Fig. 5 C ) and D. baeticus ) or eyesless ( D. murgis and D. lusitanicus ). Chelicerae with three teeth on promargin, the basal smallest. Retromargin with a series of small denticles (from 12 to 6). Leg formula: I>IV>II>III. Opisthosoma sub-elliptical in dorsal view.

Male palp. ( Figs 2 A–F ; 5 A–B) Embolus filamentous progressively acuminate, partially bordering the tegulum through a semicircular course. Apex located on the inner concavity of TTA p2. TTA with two processes: TTA p1 and TTA p2. TTA p2 located in apical position and serving as conductor of embolus. Median Apophysis absent or poorly developed in D. baeticus and D. lusitanicus , in this case reduced to a small finger like process fused to the tegulum and related to the TTAp2. Paracymbium large with well developed dorsal and ventral processes. Dorsal process widely ramified in the Iberian species, reduced in the Italian species (except in D. speluncarum ). Ventral process reduced to a translucent lamella with secondary apophyses.

Epigynum and vulva. Epigynum ( Fig. 3 A–F ) wide and convex, fitted with a short or long prominent median septum, caudally projected by a bell-shaped flap. Vulva ( Fig. 4 A–F ) with a pair of large lateral pockets. Small, circular or oval spermathecae located in the middle-lower part on both sides of the vulva, in D. menozzi more apparent and kidney-shaped spermathecae. Short and thin insemination ducts starting from the basal part of the spermathecae, and directed towards the copulatory orifices forming a slight curvature towards both sides of the vulva. Copulatory orifices located on both sides of the median septum.

Distribution: Domitius n. gen. includes a group of species spread by western European Peninsulas (Iberian and Italian). Although the distribution area of the new genus is quite extensive, the seven species grouped in the new genus have very restricted ranges, ranging from a single cave to a unique limestone massif. For example, D. sbordonii is known from three very close caves in Valle Serena, near Supino, (Lazio), central Italy; D. menozzii is recorded from few cavities in Liguria, near Sant’Olcese and D. speluncarum is restricted to a dozen localities of Liguria and Toscana (Northern Italy). Several authors have confused this species with K. eremita giving it a wide distribution ( Dresco, 1966: p 801) although the localities where its presence has been confirmed are restricted to Liguria and Toscana. D. murgis is known only from the type locality, in the Sima Termal, Sierra de Gador, near El Egido (Almería). D. baeticus is restricted to the karst landscapes of the high part of the Cazorla, Segura and Las Villas Natural Park (NE Jaén, Spain). D. luquei , is endemic of the Cantabrian Mountains and its range is restricted to cavities of Cantabria and Asturias, in the North of Iberian Peninsula. Finally, D. lusitanicus inhabits some caves of the karst reliefs of the Santarem and Leiria districts, North of Lisbon, Portugal ( Fig. 6 )

Composition. Domitius baeticus ( López-Pancorbo & Ribera, 2011) n. comb. , Domitius murgis ( Ribera & De Mas, 2003) n. comb. , Domitius lusitanicus (Fage, 1931) n. comb. , Domitius luquei (Ribera & Guerao, 1995) n. comb. , Domitius sbordonii (Brignoli, 1979) n. comb. , Domitius menozzii (Caporiacco, 1934) n. comb., and Domitius speluncarum (Pavesi, 1873) n. comb.

Figures

FIGURE 2. Palps in ventral views. A: Domitius baeticus (López-Pancorbo & Ribera, 2011), B: Domitius luquei (Ribera & Guerao, 1995), C: Domitius lusitanicus (Fage, 1931), D: Domitius murgis (Ribera & De Mas, 2003), E: Domitius menozzii (Caporiacco, 1934) and F: Domitius sbordonii (Brignoli, 1979). Abbreviations: do, dorsal paracymbium process; e, embolus; MA, median apophysis; t, tegulum; TTA, theridioid tegular apophysis; TTA p1, process 1 of TTA; TTA p2, process 2 of TTA; v, ventral paracymbium process. Scale bars:0.2 mm.

FIGURE 4. Vulva in dorsal views. A: Domitius baeticus (López-Pancorbo & Ribera, 2011), B: Domitius luquei (Ribera & Guerao, 1995), C: Domitius lusitanicus (Fage, 1931), D: Domitius murgis (Ribera & De Mas, 2003), E: Domitius menozzii (Caporiacco, 1934) and F: Domitius sbordonii (Brignoli, 1979). Abbreviations: cd, copulatory duct; co, copulatory orifice; lp, lateral pockets; s, spermatecae.Scale bars: 0.2 mm.

FIGURE 5. Domitius speluncarum (Pavesi, 1873). A: palp ventral view, B: palp retrolateral view, C: male prosoma dorsal view.Scale bars: A–B, 0.2 mm; C, 0.5 mm.

FIGURE 6. Distribution of the genus Domitius n. gen. in the western Mediterranean.

FIGURE3. Epigynes in ventral views.A: Domitius baeticus (López-Pancorbo & Ribera, 2011), B: Domitius luquei (Ribera & Guerao, 1995), C: Domitius lusitanicus (Fage, 1931), D: Domitius murgis (Ribera & De Mas, 2003). E: Domitius menozzii (Caporiacco, 1934). F: Domitius sbordonii (Brignoli, 1979.Abbreviations:MS, medianseptum.Scale bars: 0.2 mm.