Microtityus (Parvabsonus) eustatia Armas, 2018

de Armas, Luis F., 2018, A new species of Microtityus from the British Virgin Islands, West Indies, and new localities for other scorpions (Scorpiones: Buthidae, Scorpionidae), Euscorpius 264, pp. 1-10 : 2-6

Microtityus (Parvabsonus) eustatia Armas , sp. n.

Figures 2–17, Table 1 http://zoobank.org/urn:lsid:zoobank.org:act:E3407D

78-BEBB-4C66-9029-4B68076EBED5

TYPE DATA. BRITISH VIRGIN ISLANDS: Eustatia Island (18°30’41.5” N, 64°21’22.5 W): Trail to Hidden Beach : 1♀ holotype, 1♂ paratype (IES-3.3786), Spring 2017, leg. E. L. Speissberger. Virgin Gorda Island (18°28′54.8″ N, 64°23′20.95″ W): Biras Hill: 1 ♂ paratype (IES-3.3787), 09 November, 2016, leg . R. Winston , Winkler funnel of leaf litter under Pisonia subcordata Sw. Great Camanoe Island, (1) 18°28’30” N, 64°31’55” W, 2 ♀♀ paratypes (IES-3.3788), 11 July 1994, leg. M. A. Ivie, M. S. Becker and S. A. Bucklin, litter from dry forest; (2) Cam Bay, 18.4705°N, 64.5314° W; 3 m a.s.l., 1♀ 1♂ paratypes ( MTEC) , 11 July 1994, leg. M. A. Ivie, S. A. Bucklin & M. S. Becker.

DISTRIBUTION. Known only from the British Virgin Islands ( Fig. 2).

ETYMOLOGY. The specific epithet is a noun in apposition, taken from the name of the Eustatia Island housing the type locality.

DIAGNOSIS. A small species (14–17 mm) that closely resembles M. waeringi Francke & Sissom, 1980 , from which it clearly differs by having: (1) pedipalps fixed finger with ten rows of denticles (nine in M. waeringi ); (2) metasoma somewhat more attenuate in both sexes (vesicle length/width ratio = 1.8 – 2.1 vs 1.5 – 1.6 in M. waeringi ; (3) pectines with slightly higher tooth count (10-12 in the females and 12–13 in the males, whereas in M. waeringi females have 9–11 teeth, and males, 10– 12); (4) darker pattern on the entire body. This new species differs from M. vieques Teruel, Rivera & Santos, 2015 from Vieques Island, southeastern Puerto Rico, and M. santosi Teruel, Rivera & Sánchez, 2016 from Culebrita (an islet near Culebra Island, northeastern Puerto Rico), by having a higher pectinal tooth count (9 in the female of M. santosi , 10 in both sexes of M. vieques ). Also, female of M. santosi has the basal plate of the pectines wider than long, whereas in both sexes of M. vieques the basal middle lamella of the pectines is clearly enlarged.

FEMALE HOLOTYPE ( Fig. 3, 5–6, 9–11, 13–17). Base color light yellowish brown, slightly paler on legs and venter and becoming slightly darker on metasomal segment V and telson, densely spotted with dark brown all over the body, appendages, pectines and the ventral region ( Fig. 3, 5–6, 10). Chelicerae yellowish, with distal one-third of manus and basal half of fingers intensely infuscate and faint inner dark reticulations. Pedipalp femur very densely spotted with dark brown on all surfaces, except ventrally immaculate; patella very densely spotted with dark brown on all surfaces except ventral, which possesses spots only in the distal one-third and the external margin; chela with manus spotted on external surface and carinae; fingers strongly infuscate but with yellowish tips. Carapace densely spotted with dark brown; tergites densely spotted with dark brown, without clearly defined pattern of longitudinal dark bands; venter densely spotted with dark brown all over leg coxae, sternum, genital operculum, pectines (including basal plate and middle lamellae) and sternites ( Figs. 5-6, 10). Legs with trochanter, femur and patella very densely spotted with dark brown externally, sparsely spotted both dorsally and ventrally, but immaculate internally, tibia and tarsi annulated: basal half blackish brown, distal half pale yellowish, most conspicuously on basitarsi. Metasoma strongly spotted with dark brown on all surfaces, slightly darker on segment V and telson.

Carapace subtriangular, 1.12 times wider than long. Anterior margin bilobed. Carinae: anterior median, anterior lateral, superciliary, central median, posterior submedian and posterior median granulose to subgranulose, other carinae obsolete to absent. Tegument finely and densely granulose. Median eyes separated by 1.07 times the ocular diameter; three pairs of lateral eyes.

Mesosoma. Tergites with the same granular sculpture as on carapace; I–VI with three longitudinal carinae, which are granulose and moderately projected beyond the posterior margin of every tergite ( Fig. 9), VII with five finely serrate longitudinal carinae. Sternite III mostly coriaceous, laterally depressed with disperse small granules on anterior sub-margin, posterior margin slightly convex; IV–VII with two pairs of granulose longitudinal carinae (submedian and laterals), coriaceous on IV and finely granulose on V–VII ( Fig. 10), with straight posterior margin on V–VI and a vestigially bilobed on IV; spiracles oblique and small, suboval to deltoid.

Metasoma. Segments I–II with ten carinae, III–IV with eight, V with five, all finely serrate to subserrate on I–IV, finely subcrenulate on V; dorsal lateral carinae with terminal denticle moderately enlarged and sharp on I–III, slightly enlarged and blunt on IV. Intercarinal spaces finely and densely granulose. Telson ( Fig. 11): vesicle oval, smooth, with poorly developed ventral median carina, subaculear tubercle moderately-sized, subconical with its peak rounded, without dorsal granules; aculeus 0.8 times as long as the vesicle.

Chelicerae. Dentition typical of the genus. Tegument smooth, dorsally with coarse, lustrous granules irregularly arranged along the distal margin, which are accompanied by a few macrosetae.

Pedipalps ( Figs. 13–17). Orthobothriotaxic A-α (internal surface of the femur with d 2). Femur with five denticulate carinae, intercarinal spaces finely and densely granulose, with coarser granules dispersed, internal surface with the four internal (i 1-4) trichobothria surrounding a conical spur of moderate size. Patella with seven crenulate carinae, except the internal median which is serrate; intercarinal spaces with the same granular sculpture as on femur, internal surface with two spiniform denticles, being the distal the largest. Chela oval, 0.65 times as wide as the patella; manus with nine finely granulose to costate carinae, intercarinal spaces coriaceous to very finely granulose; fixed finger with 10 principal rows of denticles ( Fig. 16); movable finger with 10 principal rows of denticles plus an apical subrow of four denticles ( Fig 17), without basal lobe.

Legs. Slender, all carinae finely granulose to serrate; intercarinal spaces coriaceous to finely granulose, with dispersed coarser granules. Sternum type 1, small and pentagonal.

Pectines ( Fig. 6). Rather small, not reaching the apex of leg IV trochanter; tooth count 11/12; basal middle lamella no enlarged, suboval. Basal plate subrectangular, longer than wide, posteriorly spatulate.

MALE ( Figs. 4, 7–8, 12). Differs from the female in the following characters: (1) smaller in size ( Table 1); (2) general pattern paler, with pedipalps manus and pectines immaculate; (3) genital papillae present; (4) basal plate of the pectines wider than long, not spatulate; (5) carapace as long as wide; (6) pectines longer, reaching the apex of the leg IV coxae; (7) mesosoma slender.

VARIATION. Pectinal tooth count varied as follows for females: 10 (1 comb), 11 (4 coms), 12 (3 combs); for males: 12 (1 comb), 13 (5 combs). One female paratype has basal plate of the pectines almost as wide as long. Both female paratypes have sternite III with posterior margin vestigially emarginate.

ANOMALOUS LEG. The right leg I of the holotype is very small ( Fig. 3), having only four segments: coxa, trochanter, short and conical femur, short unidentified segment (tarsus?) and claws. Its origin is unknown, but perhaps it was caused by damage or loss of this leg during one of the early life stages and posteriorly underwent a partial regeneration.

NATURAL HISTORY. The type series was mainly collected in the litter of dry forests not higher than 100 m a.s.l., sympatrically with Centruroides griseus and Heteronebo yntemai . The specimen from Virgin Gorda was found in litter from water mampo tree ( Pisonia subcordata Sw. , Nyctaginaceae ), at 93 m a.s.l. One of the females collected in July has well developed embryos.