Euscorpius stefaniae, Tropea & Parmakelis, 2022

Tropea, Gioele & Parmakelis, Aristeidis, 2022, Reconsideration of some populations of Euscorpius concinnus complex (Scorpiones, Euscorpiidae), ZooKeys 1100, pp. 117-164 : 117

Euscorpius stefaniae sp. nov.

Figs 13 , 14 , 15 , 16

Type material.

Holotype: ♂, Italy, Veneto, Euganean Hills, August 2017, leg. S. Tropea, (GTC).

Paratypes: Italy: Veneto: Euganean Hills, August 2017, leg. S. Tropea, 9 ♂♂, 12 ♀♀ paratypes (GTC); same data but August 2013, leg. S. Tropea, 2 ♂♂ imm., 3 ♀♀ (which 1 imm.) paratypes (GTC).

Other examined specimens

(not included in type series). Italy, Veneto: Euganean Hills, 18 August 2012, leg. M. Fontana, 2 ♂♂ imm., 1 ♀ imm. (GTC).

Etymology.

The specific epithet is in homage to the sister of the first author, Stefania Tropea, for her kind support and enthusiasm shown in several field trips.

Known geographic range.

Italy: Veneto (Fig. 32 ).

Diagnosis.

Medium Euscorpius species, total length 27-33 mm. The adults are usually blackish coloured, with more or less marked reddish brown marbling, in the less granulated areas, and chelae with fingers ranging from pale yellowish brown to dark reddish brown with blackish reticulation. Some specimens may be reddish brown. The number of trichobothria on the pedipalp manus ventral surface is four (V1-3 + Et1). Trichobothria est and dsb on fixed finger are respectively located distally and proximally to the notch of the fixed finger. The number of trichobothria on the pedipalp patella ventral surface usually is eight (in 81.67% of the pedipalps examined). The number of trichobothria on pedipalp patella external surface usually is: eb = 4, eba = 4, esb = 2, em = 4, est = 4, et = 6. The pectinal teeth number in males usually is nine (in 92.86% of the pectines examined) and in females mostly seven (seven or eight). Dorsal patellar spur well developed. Femur usually slightly shorter than patella. Carapace approximately as long as wide, but it can be both slightly longer and shorter. Carinae V1 follows an external direction to the trichobothria Et1, without forming a Y-shape. Spinules on legs ending with a Y-shape. Ventrolateral and ventromedian carina on metasomal segment V formed by small serrulated granules.

Trichobothrial and pectinal teeth count variation.

The variation observed in 30 examined specimens (14 ♂♂ and 16 ♀♀) is given below.

Pectinal teeth in males (n = 28): 9/9 (12), 9/10 (1), 10/9 (1); in total, 9 in 92.86% (26/28) and 10 in 7.14% (2/28); mean = 9.07, SD = 0.26.

Pectinal teeth in females (n = 32): 7/7 (11), 8/7 (2), 8/8 (3); in total, 7 in 75% (24/32) and 8 in 25% (8/32); mean = 7.25, SD = 0.44.

Pedipalp patella trichobothria Pv (n = 60): 7/7 (2), 7/8 (2), 8/6 (1), 8/7 (2), 8/8 (21), 8/9 (1), 9/8 (1); in total, 7 in 13.33% (8/60), 8 in 81.67% (49/60) and 9 in 3.33% (2/60); mean = 7.90, SD = 0.40.

Pedipalp patella trichobothria Pe (n = 60): et = 5/5 (2), 6/1 (1), 6/5 (2), 6/6 (23), 6/7 (1), 7/7 (1); in total, 5 in 10% (6/60), 6 in 83.33% (50/60) and 7 in 5% (3/60), mean = 5.95, SD = 0.39;

est = 2/4 (1), 3/2 (1), 3/3 (1), 3/4 (1), 2 (4/3), 4/4 (24); em = 3/3 (1), 3/4 (1), 4/3 (1), 4/4 (27); esb = 2/2 (30); eba = 3/3 (1), 4/3 (1), 4/4 (28); eb = 4/3 (1), 4/4 (27), 4/5 (1), 5/4 (1).

Description of the male holotype.

Colouration. A general black base colour with more or less marked paler marbling or reticulation, reddish brown, in the less granulated areas, especially of the metasoma, legs, pedipalps and chelicerae; telson mostly black with two ventrally longitudinal pale brown stripes and one for each side, with yellowish pale brown sting; pale brown chelicerae with dark brown reticulation; chelae with fingers ranging from pale yellowish brown to dark reddish brown with blackish reticulation; legs with almost completely yellowish tarsus, the basitarsus and tibia are especially internally yellowish with dark blackish brown marbling, the patella and femur are mostly dark with paler marbling; pectines and genital operculum yellowish; sternites range from almost completely black to the most distal to yellowish marbled brown of the most proximal.

Carapace. Almost completely covered by a dense granulation; anterior edge is mostly straight and granulate; deep posterior lateral furrows; two pairs of lateral eyes, and a pair of median eyes; length from centre of median eyes to anterior margin is 44% of carapace length.

Mesosoma. The tergites are thickly granulated; sternites glossy and finely punctuated; small spiracles inclined to ~ 45° downward towards outside.

Metasoma. Dorsal carinae on segments I-IV with spaced granules; ventrolateral carinae on segment I absent, on segment II and III smooth or obsolete, on segments IV rouge, on segment V slightly serrulated granules are present; ventromedian carinae absent on segment I-IV, on segment V it consists of small, slightly serrulated granules; intercarinal surfaces are mostly finely granulated with some area, especially those of paler colour, smooth.

Telson. Vesicle mostly smooth, with ventral setae of different size, especially near the vesicle/aculeus juncture.

Pectines. Teeth number 9/9; middle lamellae number 6/5; several microsetae on proximal area of teeth, marginal lamellae, and middle lamellae.

Genital operculum. The genital operculum is formed by two longitudinally devised subtriangular sclerites with genital papillae protruding.

Sternum. Pentagonal shape, type 2; slightly wider than long, with a deep posterior emargination.

Pedipalps. Coxa and trochanter with tuberculated carinae. Femur: dorsal internal and external and ventral internal carinae tuberculated; irregular ventral external carinae formed by tubercles just on 1/3 or 1/4 of femur length; external median carinae formed by lightly serrulated tubercles; anterior median carinae formed by some spaced conical tubercles with three macrosetae; intercarinal spaces granulated. Patella: dorsal and ventral internal carinae tuberculated; ventral external carinae crenulated; dorsal external carinae slightly crenulated to rough; intercarinal surfaces finely granulated, especially on the dark reticulations near the carinae. Dorsal patellar spur well developed. Chela: chelal carina D1 is distinct, strong, dark and smooth with a few tubercles proximally; D4 is rounded with a few spaced granules; V1 is distinct, strong, dark, from rough to smooth, following an external direction to the trichobothria Et1; V3 is rounded with scattered granules; external carina granulated; intercarinal tegument granulated; the fixed and movable fingers with little marked notch and lobe, respectively.

Finger dentition. In the most distal part is present a DD on the tip; MD is formed by very small denticles closely spaced forming an approximately straight line, discontinued at level of the OD; fixed finger has 6/6 OD and 11/12 ID; movable finger has 8/8 OD and 16/16 ID.

Trichobothria. Chela: trichobothria on the pedipalp manus ventral surface V = 3/3 (V1-3) + Et1 = 1/1; trichobothrium V4 situated on the external surface of the chela carina near the carina V1; trichobothrium ratio of et-est/est-dsb is ~ 1. Patella: Pv = 8/8; et = 6/6, est = 4/4, em = 4/4, esb = 2/2, eba = 4/4, eb = 4/4. Femur: trichobothrium d is slightly proximal to i, while trichobothrium e is well distal to both d and i, and situated on dorsal surface on dorsal external carina.

Legs. Two pedal spurs present; no tarsal spur; ventral row of tarsus with a total of 9/12 spinules on leg III, of increasing size from proximal to distal, ending with a Y-shape; three main flanking tarsal setae present. Tubercles present on ventral and dorsal surface of all leg femora.

Chelicerae. Typical of the genus Euscorpius .

Description of the hemispermatophore.

Type A. It has a well-developed lamina tapered distally; well-developed basal constriction present; truncal flexure present; median projection with lde, ldi, and lb; internal projection distally with seven or eight tines in its crown. The number and the shape of tines of the crown varied between specimens and between the right and the left hemispermatophores.

Comments.

Euscorpius stefaniae sp. nov. is the only species of E. concinnus group occurring in northeastern Italy. In fact, to the east of this species’ range, the genus Euscorpius s. str. is mostly represented by E. tergestinus , the most phylogenetically closely related species to E. concinnus group. This might suggest that E. stefaniae sp. nov. could be the most basal species of the latter species group, given that the dispersal and speciation of the genus Euscorpius s. str. seems to have proceeded in the direction from east to west. The dispersal and speciation probably continued westwards, following the Prealps and then the Apennines toward the south, which were the only possible dispersal routes since the relatively recent Padan Plain did not exist at that time. Euscorpius stefaniae sp. nov. could be a relict species, and the others species of the E. concinnus group speciated and colonised new areas approximately at the same period, but at a later time than E. stefaniae sp. nov., after the extinction of the ancestral population from most areas, as suggested by the 16S phylogeny (not shown here). However, in the concatenated tree inferred with 16S + COI markers, the most basal species, placed after E. tergestinus , is E. concinnus , with E. stefaniae sp. nov. in the apical position. This could be explained by the extinction of all ancestral populations in the north, and then the subsequent dispersal and speciation from areas, for example, of Tuscany. Euscorpius stefaniae sp. nov. is well separated from the other species of E. concinnus group with a divergence in 16S of 3.1%-4.2%, almost equal to that between E. tergestinus and E. concinnus . Morphologically, like the remaining species of the E. concinnus group and the numerous cryptic species complexes described in recent years, E. stefaniae sp. nov. is difficult to distinguish without knowing its origin and having a large sample size. However, it has morphological characters that show a good separation from other related species: E. stefaniae sp. nov. has the highest mean Dp in males (9.07) and the highest percentage of Dp = 9 (92.86%). The related species, on average, range from 8.05 to 8.25 except E. niciensis stat. nov., which has an average of 8.72, and Dp = 9 ranging from 10.46% to 19.64%, except E. niciensis stat. nov. which has 60.26%, a much lower value. Also, the average is higher in females compared to the other E. concinnus group species, but not significantly. Another interesting value in this species is Pv = 8 in 81.67%. In fact, although considered a typical value for the E. concinnus group, this species has the higher percentage with this number than the other species which have values ranging from 25% to 65%.

The Euganean Hills are a group of hilly reliefs of volcanic origin with a height ranging from ~ 200-600 m, which rises almost isolated to the southwest of Padua. The climate and microclimates on the Euganean Hills can vary greatly depending on the area. They can be mainly divided into sub-Mediterranean, typical of the south-facing slopes, and sub-mountain typical of the north-facing slopes. Depending on the slope and area, the woods can be quite humid. The specimens were found mostly under stones in the less humid areas and mostly under bark in the more humid areas.

Figures

Figure 13. Dorsal and ventral view of Euscorpius stefaniae sp. nov. male holotype. Scale bar: 4.00 mm.

Figure 14. Dorsal and ventral view of Euscorpius stefaniae sp. nov. female paratype. Scale bar: 4.00 mm.

Figure 15. Euscorpius stefaniae sp. nov. male holotype except Figs C and N, that are of a female paratype A carapace B external view of chela of adult male C external view of chela of adult female D ventral view of pedipalp patella E dorsal view of pedipalp patella F external view of pedipalp patella G ventral view of chela H dorsal view of chela I ventral view of metasomal segment V J lateral view of metasomal segment V K telson of adult male L telson of adult female.

Figure 16. Live specimens of Euscorpius stefaniae sp. nov.

Figure 32. Maps of the known geographic ranges of the species treated herein.