Typhlonesticus santinellii Isaia and Ribera, 2023

Isaia, Marco, Nicolosi, Giuseppe, Infuso, Alessandro & Ribera, Carles, 2023, Two new subterranean Typhlonesticus (Araneae: Nesticidae) from the Alps with notes on their ecology, distribution and conservation, Arthropod Systematics & amp; Phylogeny 81, pp. 801-818 : 801

3.3.2. Typhlonesticus santinellii Isaia and Ribera sp. nov.

Fig. 3A-E , 5B, D , 7C

Examined material.

Holotype: ITALY, Lombardia, Province of Bergamo: Oneta, Miniere di Gorno , Alpe Grem , Galleria del Pozzo (Fig. 7G ), 45.8833°N, 9.8243°E, 1,208 m a.s.l., 14.X.2022, Falgari N., Isaia M., Nicolosi G., Pantini P., Scolari F. leg. 1m (MCSNB) . - Paratypes: ITALY, Lombardia, Province of Bergamo: Oneta, Miniere di Gorno, Alpe Grem , Cantiere #7, 45.8862°N, 9.8235°E, 1,320 m a.s.l., 14.X.2022, Falgari N., Isaia M., Nicolosi G., Pantini P., Scolari F. leg. 1f (CI) • Oneta, Miniere di Gorno , Alpe Grem, Galleria del Pozzo (Fig. 7G ), 45.8833°N, 9.8243°E, 1208 m a.s.l., 14.X.2022, Falgari N., Isaia M., Nicolosi G., Pantini P., Scolari F. leg. 1f (MCSNB) • Monasterolo Castello, Grotta Murdosso [LoBG 7407] (Fig. 7H ), 45.7474°N 9.9542°E, 1092 m a.s.l., 12.V.2019, Santinelli R. leg. 1f, 1 m subadult (CI) .

Diagnosis.

Males of Typhlonesticus santinellii sp. nov. differ from T. morisii and T. angelicus sp. nov. by the shape of p1 and p2 processes, the shape of the median apophysis (Figs 3D , 5D ) and by the shape and arrangement of the paracymbial apophyses, mainly the ventral one ( “vp” in Fig. 3D, E ), which is shorter and more tapering in T. santinellii sp. nov. than in T. angelicus sp. nov. and T. morisii . - Females are best diagnosed by the orientation of the insemination ducts, and the shape of the spermathecae (Figs 3A, B , 5B ).

Description of the male.

Male holotype from Miniere di Gorno, Galleria del Pozzo, 45.8833°N, 9.8243°E, 1208 m a.s.l., 14.X.2022, Falgari N., Isaia M., Nicolosi G., Pantini P., Scolari F. leg. - Coloration: Carapace yellow-brown. Head region of the same color. Sternum yellow brown, without pattern. Opisthosoma grey-white without pattern. Legs same color as prosoma, all trochanters notched. - Prosoma: Carapace 1.42 long, 1.30 wide. Cephalic region not differentiated from the rest of the carapace. Clypeus height 0.32 (under AME). Labium as long as wide or moderately wider than long. Sternum 0.88 long, 0.90 wide. Eyes reduced and lacking pigment, no corneal lenses are visible. Both eye rows recurved in dorsal view (PER 0.43 wide, AER 0.37), Eye diameter: AME 0.01, ALE 0.06; PME 0.05; PLE 0.06. - Opisthosoma: 1.84 long, 1.13 wide. Total length 3.26 (3.43 including spinnerets). Leg formula: I>II>IV>III. - Appendages: Chelicerae: 0.72 long, 0.30 wide, with three equally spaced teeth on promargin and 18-20 very small teeth grouped on retromargin. Male palp (Figs 3D, E , 5D ): Paracymbium short. Ventral process consisting of a long and flattened lamella, straight, tapering in the distal part, ending in a thin spine, and a dorsal process scarcely developed consisting of a short laminar apophysis, perpendicularly bent at the apex, ending in a rounded lobe. Conductor complex with two well developed processes (p1 and p2): p1 is longer than wide, pointed, tapering along its length in lateral view (Figs 3D , 5D ); p2 is in an apical position and ending with two almost parallel small hooks, running as a conductor for the embolus (Figs 3D , 5D ). Embolus filamentous following a semi-circular course towards the apex and bordering the tegulum (Figs 3D , 5D ). Large and well-developed median apophysis, ventrally directed, wider at its base and narrower at its medial-final part, cone-shaped with a blunt end. (Figs 3D , 5D ). - Leg measurements: Leg I: femur 5.23, patella 0.76, tibia 5.36, metatarsus 5.30, tarsus 1.80, total 18.45. Leg II: femur 3.98, patella 0.68, tibia 3.78, metatarsus 3.69, tarsus 1.39, total 13.52. Leg III: femur 3.96, patella 0.65, tibia 3.32, metatarsus 3.15, tarsus 1.20, total 12.28. Leg IV: femur 3.99, patella 0.66, tibia 3.77, metatarsus 3.64, tarsus 1.35, total 13.41. Palp: femur 1.02, patella 0.24, tibia 0.31, tarsus 0.84, total 2.41.

Description of the female.

Female paratype from Miniere di Gorno, Alpe Grem, Galleria del Pozzo, 45.8833°N, 9.8243°E, 1,208 m a.s.l., 14.X.2022, Falgari N., Isaia M., Nicolosi G., Pantini P., Scolari F. leg. - Coloration: Carapace pale yellow. Head region of the same color. Sternum yellow brown, without pattern. Opisthosoma grey-white without pattern. Legs same color as prosoma. - Prosoma: Carapace 1,51 long, 1,36 wide, approximately circular in dorsal view. Cephalic region not differentiated from the rest of the carapace. Clypeus height under AME 0.29, under ALE 0.298. Labium as long as wide or moderately wider than long. Sternum 0.79 long, 0.96 wide. Eyes reduced and depigmented, no corneal lenses are visible. Both eye rows recurved in dorsal view, PER 0.49 wide, AER 0.36. AME reduced to a small spot of pigment. Eye diameter: AME 0.01, ALE 0.05; PME 0.06; PLE 0.06. - Opisthosoma: 2.01 long, 1.67 wide. Total length 3.52 (3.65 including spinnerets). Leg formula: I>II>IV>III. Epigynal plate 0.30 long, 0.55 wide, convex and prominent, without sclerotized plates (Figs 3A , 5B ). The posterior edge is slightly sclerotized. Spermathecae and insemination ducts can be observed through the tegument. Vulva simple (Figs 3B , 5B ), consisting of two small rhombohedric spermathecae, insemination and fertilization ducts. Insemination ducts coiled, forming three laps around the fertilization ducts before reaching the spermathecae (Fig. 3A, B ). - Appendages: Chelicerae 0.76 long, 0.28 wide with three equally spaced teeth on promargin and 18-20 very small teeth grouped on retromargin. Legs same color as prosoma. - Leg measurements: Leg I: femur 4.48, patella 0.79, tibia 4.46, metatarsus 4.12, tarsus 1.59, total 15.44. Leg II: femur 3.52, patella 0.74, tibia 3.11, metatarsus 3.08, tarsus 1.26, total 11.71. Leg III: femur 2.72, patella 0.65, tibia 1.97, metatarsus 2.19, tarsus 0.99, total 8.52. Leg IV: femur 3.73, patella 0.78, tibia 3.02, metatarsus 2.74, tarsus 1.19, total 11.46. Palp: femur 1.09, patella 0.31, tibia 0.60, tarsus 1.14, total 3.14.

Etymology.

The species is dedicated to the speleologist Roberto “Robertone” Santinelli, who first collected the female specimen in Murdosso cave, allowing the diagnosis of the new species. Noun in genitive.

Distribution, sampling notes and ecology.

Typhlonesticus santinellii sp. nov. is restricted to subterranean habitats of the central portion of Alpi Orobie, within the section of Alpi e Prealpi Bergamasche ( Marazzi 2005) (Fig. 6 ). Three populations are known so far (two of them very close to each other), covering an area of less than 5 km2 in the Val del Riso, across the municipalities of Monasterolo Castello (Murdosso cave) and Oneta (mining complex of Gorno), both in the Province of Bergamo. The Murdosso cave is a wild cave opening in a beech forest in the nearby of Colli di San Fermo. The first female specimen was collected by Roberto Santinelli under big rocky debris, during the unblocking operations of the cave conducted by the local speleological groups “Underland” and "I Tassi". Despite several attempts, no further specimens were collected at Murdosso cave after the collection of the first female. The two further occurrences refer to the galleries of the abandoned mining complex of Gorno, nowadays "Ecomuseo delle miniere di Gorno", an ethnological museum dedicated to the cultural heritage of the mining activity in this area. The male and a few other specimens were collected during our biospeleological expedition in the mining complex led by Fabrizio Scolari (Ecomuseo delle miniere di Gorno) in October 2022. The galleries in which the new species was found open in alpine grasslands at 1,200-1,300 m asl. Individuals of T. santinellii sp. nov. were preferably found on cave walls and among rocks near the ground, hanging upside down on their criss-cross web. Investigations at the mining complex of Gorno started following the suggestion of Marco Valle, Director of the Museo Civico di Scienze Naturali di Bergamo who conducted some biological investigations in the mining complex of Gorno in the early 1980s, together with the local biospeleologist Gianni Comotti. Marco Valle noticed that among the arachnological material collected during those explorations there was a remarkable nesticid, that was sent for examination to Konrad Thaler. The material was returned by Thaler to the Museum of Bergamo in 1984, except for one female identified as " Nesticus cf. morisii ", which was retained for further studies. Despite our search in the Thaler collection and elsewhere, we were not able to locate such material. However, our recent finding of the new species in the mining complex of Gorno confirmed Marco Valle’s and Konrad Thaler’s first impressions. - Typhlonesticus santinellii sp. nov. was collected in a natural cave and in the mining complex of Gorno at a mean altitude of 1,206 m (n = 3) and inhabits sites with mean annual temperatures from 6.3 to 7.8°C (mean = 7.0°C; range: 1.5; n = 3).

Conservation status and basic information for an IUCN Red List assessment. Range description, Area of Occupancy (AOO) and Extent of Occurrence (EOO).

The species is endemic to a small sector of Alpi Orobie covering an altimetric range of approximately 250 m (min-max elevation 1,092-1,320 m) (Fig. 6 ). Three populations are known so far (two if considering the two nearby populations of the mining complex Gorno as one), encompassing an estimated EOO of 4 km2 and an AOO of 8 km2. Similarly to T. angelicus sp. nov., we infer a decline in both EOO and AOO as a result of global warming. It is assumed that it has a very low dispersal capacity. - Locations: Global warming is expected to affect all known populations of T. santinellii sp. nov., consequently, one single location should be considered for the assessment risk of this species. - Threats: The species is potentially exposed due to its extremely narrow geographic distribution range, its low dispersal capacity and its low thermic tolerance related to the high level of adaptation to subterranean life. - Conservation actions: In light of the ongoing global warming, it is worth considering the extinction risk of T. santinellii sp. nov. As for T. angelicus sp. nov., it is not possible to provide any precise management actions, but the inclusion on the IUCN Red List represents an important starting point for its conservation. The subterranean sites of the mining complex of Gorno hosting T. santinellii sp. nov. benefit from being included in sites of Conservation importance, namely SC IT2060009 Val Nossana - Cima di Grem, managed by the Regional Park of Orobie Bergamasche. The current management of the subterranean site as tourist attractions does not seem to compromise the survival of this species.

Figures

Figure 3. Typhlonesticus santinellii sp. nov., paratype female from Monasterolo Castello, Grotta Murdosso [LoBG 7407] (Santinelli R. leg., 12. V. 2019) (A, B, C) and holotype male from Miniere di Gorno, Alpe Grem, Galleria del Pozzo (Falgari N., Isaia M., Nicolosi G., Pantini P., Scolari F. leg., 14. X. 2022) (D, E). Epigyne in ventral view (A), vulva in dorsal view (B), female cephalothorax in frontal view (C), left male pedipalp in ventral view (D) and male cymbium in dorsal view (E) (see section 2.2.3. for abbreviations). Scale bars 0.2 mm.

Figure 5. The four Italian species of Typhlonesticus: photographs of vulvae (A, B, E, F) and left male pedipalps in prolateral view (C, D, G, H). A, C Typhlonesticus angelicus sp. nov.; B, D Typhlonesticus santinellii sp. nov.; E, G Typhlonesticus idriacus (Roewer); F, H: Typhlonesticus morisii (Brignoli).

Figure 6. Distribution of Typhlonesticus in Italy.

Figure 7. Live specimens of Typhlonesticus angelicus sp. nov. (A male), T. morisii (Brignoli) (B female) and T. santinellii sp. nov. (C female) in their natural habitats. The entrance of Grotta superiore delle Camoscere [Pi 250], type locality of T. angelicus sp. nov. (D), the military bunker of Sotterranei di Vernante, type locality of T. morisii (Brignoli) (E, F); the walls of " Galleria del Pozzo' ' within the mining complex of Gorno, type locality of T. santinellii sp. nov. (G); the entrance of Murdosso cave [Lo BG 7407], where the first female of T. santinellii sp. nov. was collected during the unblocking operations of the cave conducted by the local speleological groups " Underland " and " I Tassi " (H).