Tityus (Tityus) achilles Laborieux, 2024, sp. nov.
Creators: name: Laborieux, Léo
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Scorpiones
Buthidae
Tityus
Tityus achilles

description: Tityus (Tityus) achilles sp. nov.
ZooBank LSID: urn:lsid:zoobank.org:act: 638E2B6A-E165- 4028-99DA-B9B6B2BD6564
Holotype: adult ♂, Colombia, Cundinamarca, La Vega, Estación Experimental JCM (4.955239° N, - 74.379291° W), 1350 m a.s.l., December 20, 2023, Léo Laborieux, deposited at the Museo de Historia Natural C.J. Marinkelle (Universidad de los Andes). Catalogue number: ANDES-IN-8788.
Paratypes: 1 subadult ♀ + 1 subadult ♂, Colombia, Cundinamarca, La Vega, Estación Experimental JCM (4.955239° N, - 74.379291° W), 1350 m a.s.l., December 20, 2023, Léo Laborieux, deposited at the Museo de Historia Natural C.J. Marinkelle (Universidad de los Andes). Catalogue numbers: ANDES-IN-8789 (♂): ANDES-IN-8790 (♀).
Non-type specimens (fom the trial group): 5 ♀ + 2 ♂, immature individuals, Colombia, Cundinamarca, La Vega, Estación Experimental JCM (4.955239° N, - 74.379291° W), 1350 m a.s.l., December 20, 2023, Léo Laborieux.
Etymology: Te specific epithet refers to Greek mythology’s Achilles, for his prowess as a spear wielder.
Diagnosis
Scorpion of moderately large size for the subgenus, with a total size of 66.4 mm for the adult male holotype. General coloration dark red; carapace with median ocular tubercle and anterior margin black. Axial carina on mesosomal segments I–VII subtle with feeble granulation. Paraxial carinae vestigial in mesosoma. Intercarinal spaces moderately granular on I–VI, and strongly granulated on VII. Pectines with 16–18 teeth in males (16–18 in male holotype), 15–17 in females (15–16 in female paratype). Basal middle lamellae dilated. Basal pectinal piece without a glandular region. All metasomal carinae feebly raised and subcrenulate. Metasomal segment II with 2 vestigial lateral carinae occupying its distal fifh. Metasomal segment IV with 1 prominent spinoid posterior granule on dorsal carina, and 1–2 smaller ones on dorsolateral carina. Aculeus curvature low. Chela fingers black with yellow tips. Inner face of movable finger with 15 oblique rows of denticles. Tis species can also be distinguished by particularly low UV-induced fluorescence in live specimens. Telotarsi of leg pairs I–IV with two discrete ventro-submedian rows of setae (type II).
Description: Based on the adult male holotype and subadult female paratype (Figs 6–10).
Coloration: Overall dark and reddish. Prosoma: anterior margin of carapace and carinae around the ocular median tubercle black. Intercarinal spaces dark with a red sheen.Mesosoma: darker than carapace, with two lighter paraxial lines. Metasomal segments progressively darkening from I to V, from the same dark reddish hue to black. Dorsal side of metasoma segments lighter than ventral sides. Telson lighter than V. Venter and pectines yellowish, lighter than the rest of the body. Pedipalps: uniformly reddish with the exception of black fingers. Tips of fixed and movable fingers yellow. Chelicerae black with deep red teeth. Litle ontogenic change in coloration. Interestingly, this species shows only a low level of UV-induced fluorescence (Fig. 11), making night searches challenging.
Morphology
Carapace moderately to strongly granular, with the anterior margin presenting a marked median concavity. Furrows deep. Median ocular tubercle in a distinctly anterior position, with eyes separated by 1 ocular diameter and strong crenulate median ocular carinae becoming subcrenulate over the eyes. 3 pairs of lateral eyes, half the diameter of the median eyes. Sternum narrow, subtriangular. Mesosoma: 1 central longitudinal carina in all tergites with feeble granulation; in I–VI represented by one row of granules in the posterior quarter and two rows of granules more anteriorly. 2 vestigial paraxial carinae on tergites I–IV. Tergite VII pentacarinate, with central longitudinal carina in anterior half. Lateral and paramedian carinae in VII joined proximally by a series of vertically organized and raised granules. Transversal carinae strong and distinct on tergites II–V, partially fused to posterior margin on tergite I. Intercarinal spaces moderately granular on I–VI, and strongly granular on VII. Venter with genital operculum split longitudinally; valves subtriangular.
Pectines: pectinal tooth count 16–18 in males (N = 8, mode = 18; 16–18 in male holotype), and 15–17 in females (N = 12, mode = 16; 15–16 in female paratype). Basal middle lamellae dilated. Basal pectinal piece without a glandular region (based on female paratype). Sternites I–III feebly granular; IV and V moderately and strongly granular, respectively. Flatened triangle on the posterior margin of III, remarkably smooth. Sternite V with 2 + 2 crenulate longitudinal keels, i.e. (i) 2 paramedian keels on distal two thirds and (ii) 2 distinctly curved lateral keels occupying the second anterior quarter only. Spiracles oblique and of moderate length. Metasoma: all carinae feebly raised, subcrenulate. Setation weak. Segment I decacarinate; segment II with 8 carinae and 2 vestigial lateral carinae occupying its distal fifh. Segments III and IV with 8 carinae. Segment V with 7 carinae: 2 dorsal, 2 ventral, 1 median ventral, and 2 paramedian ventral. Posterior granules of segment III weak, tubercular. Segment IV with dorsal and dorsolateral carinae displaying 1 strong and 2–3 weaker spinoid posterior granules, respectively. Tis spinoid granule on IV’s dorsal carina is prominent, representing the metasoma’s most obvious feature. Intercarinal spaces granular in all segments. Median dorsal depression present and moderate in V. Telson feebly granular, smooth dorsally. Aculeus short with low curvature. Subaculear tooth moderate, weakly spinoid. Cheliceral dentition characteristic of family Buthidae; median tooth of fixed finger strong and rather distinct. Trichobothrial patern type A; orthobothriotaxic as defined by Vachon (1974). Dorsal trichobothria of femur arranged in α (alpha) configuration. Trichobothria d2 present on the internal face of the femur (emigrated from dorsal face). Pedipalps with moderate overall setation, but fingers with strong setation. Femur setation concentrated on ventral side; patella with some short macrosetae scatered all over. Ventral side of manus almost devoid of setation; external and dorsal sides with a higher density of macrosetae than in patella. Fingers hairy, especially on internal sides with long macrosetae. External sides of fingers with increased setation distally. Femur with five crenulate and raised carinae, as well as an additional keel-like row of granules along the proximal third of its ventral side. Patella with 7 raised keels, all subcrenulate to smooth except for the 2 internal carinae, composed of spinoid granules. Intercarinal spaces moderately and feebly granular on femur and patella, respectively. Movable fingers with 15–15 oblique rows of denticles and strong, spinoid accessory and internal granules. First two proximal rows of denticles almost fused, but distinguishable based on their accessory and internal granules. Telotarsi of leg pairs I–IV with 2 discrete ventro-submedian rows of setae (type II).
Comparisons: Tityus (Tityus) achilles shows affinities with the Colombian species Tityus Tityus) lourençoi Florez, 1996 and Tityus (Tityus) charalaensis de Mello-Leitão, 1940, with a generally dark-reddish coloration, male pedipalps slenderer than those of females, and fully parallel ventrolateral carinae on metasomal segments II–IV. It can however be easily distinguished from these by several key characters:
description: Published as part of Laborieux, Léo, 2024, Biomechanics of venom delivery in South America's first toxungen-spraying scorpion, pp. 1-16 in Zoological Journal of the Linnean Society 202 (4) on pages 6-8, DOI: 10.1093/zoolinnean/zlae161, http://zenodo.org/record/14825462