Somalibuthus sabae, Kovařík & Njoroge, 2021

Kovařík, František & Njoroge, Laban, 2021, Somalibuthus sabae sp. n., a new buthid scorpion from Kenya (Scorpiones: Buthidae), Euscorpius 332, pp. 1-19 : 4-18

Somalibuthus sabae sp. n.

( Figures 1–110 , 116–117 , Table 1) http://zoobank.org/urn:lsid:zoobank.org:act:8D0A23BD-

093B-46AE-9AE2-525CFF648549

TYPE LOCALITY AND TYPE REPOSITORY. Kenya, Kiwayu Island , Lamu County, 1°59'36.32" S 41°17'08.59" E; NMK.

TYPE MATERIAL ( NMK, NMPC). Kenya, Kiwayu Island , Lamu County, 1°59'36.32" S 41°17'08.59" E ( Fig. 117 ), 14.XII.2020, 1♂ (holotype, NMK /INV/T-238), 2♂ 4♀ (paratypes, NMK / INV/T-239-244), leg. S. Douglas-Hamilton.

ETYMOLOGY. The species is named in honor of the collector of the type series, Saba Douglas-Hamilton .

DIAGNOSIS. As for the genus, augmented with the following characters: base color yellow to orange-yellow, with fuscous markings on body and appendages, tergites with variable diffuse fuscosity; pedipalp patella smooth, dorsomedian carina obsolete in proximal half; pedipalp L/W ratios, ♂: femur 2.65–2.78, patella 2.61–2.65, chela 4.95–5.01; ♀: femur 2.64, patella 2.54–2.60, chela 4.69–4.77; metasoma with sparse fine granulation on dorsal surfaces of all segments; ventromedian carinae on metasoma II smooth anteriorly, weakly granulose posteriorly, on metasoma III weakly granulose anterior, moderately granulose posteriorly; metasomal segment L/W ratios, ♂: segment I 1.06–1.12, segment II 1.33–1.40, segment III 1.50–1.53, segment IV 1.76–1.83, segment V 2.18–2.28; ♀: segment I 1.04–1.06, segment II 1.30–1.36, segment III 1.43–1.50, segment IV 1.66–1.72, segment V 2.14–2.16; telson L/W ratios, ♂: 2.79–3.05; ♀: 2.50–2.77.

DESCRIPTION (♂ ♀). Total length 27 mm (♂) to 40 mm (♀).

Coloration ( Figs. 1–16 , 21, 23, 25, 27 , 29–48 , 91–98 ). Base color yellow to orange-yellow. Carapace and tergites with underlying diffuse fuscosity. Dark brown or black markings on: anterior margin, carinae, granules and median ocular tubercle of carapace, carinae and granules of tergites, distal half of cheliceral manus (reticulate pattern), internal and external carinae of pedipalp femur and patella, pedipalp chela manus, bases of pedipalp fingers, superior and inferior carinae of leg femora and patellae, metasomal carinae, and telson vesicle. Base color of metasoma V and telson weakly fuscous. Carapace ( Figs. 5, 11 , 17, 19 ). Trapezoidal, L/ W 0.89 –0.97. Median ocular tubercle prominent, median eyes relatively large, eye diameter/carapace midline length ratio 0.12–0.14. Five pairs of lateral eyes present (3 large major ocelli, 2 small minor ocelli). Anterior margin very weakly emarginate, nearly straight, bearing 10–13 macrosetae. Superciliary carinae strong, with coarse, fused granulation. Anterior median carinae strong, granulose, continuous over posterior 2/3 of distance from ocular tubercle to anterior margin, breaking into non-contiguous granules in anterior 1/3. Central median carinae strong, granulose, posteriorly convergent. Posterior median carinae strong but short, irregular, with large granules, not connected to central median carinae. Other carinae absent. Intercarinal surfaces with dense fine, medium and coarse granulation. Carinal and intercarinal granules polished. Central median furrow finely granulate or shagreened, posterior median and posterior marginal furrows smooth.

Chelicerae ( Figs. 21–28 ). Dorsal surface of manus smooth, glabrous, with two short, pale microsetae on apical margin, each ringed by granules. Dorsointernal carina strong, smooth to granulate, distally bearing one long, dark macroseta. Subdistal transverse carina with sparse granules, and one short, pale microseta. Fingers robust, movable finger with large dorsal distal tine slightly shorter than large ventral distal tine, dorsal margin armed with 4 denticles (subdistal, large median, 2 small basal), ventral margin with 2 denticles (larger median, smaller basal). Fixed finger with large distal tine, subdistal denticle and proximal bicusp, and single denticle on ventral surface adjacent to bicusp. Dorsal surface of movable finger smooth, with 3 short microsetae. Numerous, long fine, microsetae distributed over dorsal surface of fixed finger, internal and ventrointernal surface of distal manus, and ventrointernal surface of movable finger.

Coxosternal area ( Figs. 6, 12 , 18, 20 ). Coxa I smooth, endite with weak medial and anterior marginal granulation. Coxa II with very sparse, fine granules (♂) or smooth(♀), endite smooth except for weak, fine granulation on posterior marginal and posterior medial areas. Coxa III with very sparse, fine granules (♂) or smooth (♀). Coxa IV: in ♂ mostly smooth with very sparse, fine granules, except for medium to coarse granulation along proximal 2/3 of anterior margin, and fine granules near proximal posterior margin; in ♀ smooth except for row of fine granules near proximal posterior margin. Macroseta counts: coxa I, medial endite 2–3, distal margin 5–6; coxa II, endite 1–2, anterior margin 4–5, distal margin 2–4; coxa III, anterior margin 3–5; coxa IV, single proximal seta. Sternum type 1, subtriangular, weakly shagreened, with deep posteromedian pit, bearing 2 macrosetae. Genital opercula smooth, each sclerite with 4–5 (♂), or 9–10 (♀) macrosetae, lateral margins concave. Male with genital papillae.

Pectines ( Figs. 6, 12 , 18, 20 ). Basal piece smooth with anterior margin concave with median pit that is deeper in males, bearing 7 (♂) – 14 (♀) macrosetae. Pectines with 3 marginal lamellae, 8–10 middle lamellae including small displaced sclerite at distal end of proximal marginal lamella. Pectines extending to distal end of coxa IV in both sexes. Pectine teeth only slightly more elongate in males than females, basal tooth shorter than other teeth. Fulcra present, paired one-to-one with pectine teeth, including small fulcrum of basal tooth. Marginal and middle lamellae with numerous macrosetae, fulcra with 2–8 setae.

Hemispermatophore ( Figs. 105–110 ). Flagelliform, trunk elongate, ca. 6 times length of capsule region; flagellum with linear pars recta and pars reflecta, separated from sperm hemiduct lobes. Sperm hemiduct with 3 lobes: posterior lobe large, broadly laminate; median lobe small, acuminate; anterior lobe of intermediate length, tapered. Posterior margin of median lobe slightly overlapping posterior lobe, the two partially joined along axial suture. Basal lobe a broad, curved scoop, obliquely-angled, almost parallel to proximal-distal axis, distally connected to axial suture.

Mesosoma ( Figs. 1–6, 11–12 , 17–20 ). Tergites. Pretergites smooth, with weakly sinuous, finely corrugated posterior margins. Tergites densely granulated, with fine granules on anterior and medial areas, coarse granules on posterior and lateral areas. Tergite I without longitudinal carinae. A median carina and posteriorly convergent, paired lateral carinae present on tergites II–VI, but may be indistinct on tergite II. Tergite VII with 5 carinae, median carina a granulated hump, 2 pairs of lateral carinae strongly developed. All carinae coarsely granular, confined to posterior tergites. Tergite granulation and carination somewhat weaker in females than males. Posterior margin of tergites I–VI with 2–5 macrosetae, of VII with fine fringe of microsetae. Sternites. Sternites III–VI lacking carinae, smooth and glabrous except for sparse fine granulation on areas lateral to stigmata in males. Stigmata narrow, slit-like. Sternite III finely shagreened in lateral areas covered by pectines. Posterior margins of sternites III–VI smooth. Sternite VII smooth medially, finely granulated laterally, median pair of carinae obsolete, lateral carinae distinct, with dentate granules, confined to posterior 3/4 of sternite, more weakly developed in females. Sternite III with one to two dozen medial macrosetae, less than a dozen posterior marginal macrosetae. Sternites IV–VI with transverse series of 6 macrosetae extending across middle of sclerite, 4 sub-medial, 2 marginal. Sternites IV–V with 10–12 posterior marginal macrosetae, VI with 5–6. Sternite VII with 5–6 non-marginal, single pair of posterior marginal macrosetae, and a posterior fringe of microsetae.

Metasoma ( Figs. 93–104 ). Elongate, all segments longer than wide, posterior segments slightly narrower than anterior segments. For morphometric ratios, see diagnosis. Carination. Segments I–III with 10 complete carinae, IV with 8 complete carinae. Dorsosubmedian, dorsolateral and ventrolateral carinae strong, crenulate-granulate on segments I–IV. Lateral median carinae strong, crenulategranulate on segments I–III, more weakly marked by series of granules on IV. Ventrosubmedian carinae smooth, weak or nearly obsolete on segment I, smooth to weakly crenulategranulate on II–III, strong and crenulate-granulate on IV. Segment V with 3 complete carinae; ventrolateral carinae strong, crenulate-dentate, dentition smaller and uniform in anterior half, larger and non-uniform in posterior half; ventromedian carinae irregularly granulate, with larger granules posteriorly; ventrosubmedian carinae indistinct (♂) or weakly marked anteriorly by granules (♀); dorsolateral surfaces rounded, without carinae; lateral anal margin with 2–3 lobes, ventral anal margin with 10–12 crenulations. Intercarinal surfaces. Dorsal and lateral surfaces of all segments with fine granulation, except for smooth posterior surfaces of segments IV–V. Ventral surfaces of segments II–V with fine granulation, more sparse on II–III, more dense on IV–V. Ventral surfaces of segment I smooth. Anterior peduncles of segments I–IV densely shagreened over entire surface, of segment V shagreened only on anterior margin. Setation. All segments with long macrosetae. Variable numbers of macrosetae distributed on carinae and medial intercarinal surface of segments I–IV. Segment V with series of dorsolateral macrosetae and scattered macrosetae on lateral and ventral surfaces. Ventral posterior margins of all segments with variable numbers of macrosetae (ca. 4–9). Dorsal and ventral posterior margins of segments I–III with fine fringes of microsetae.

Telson ( Figs. 91–104 ). Vesicle ovoid, more bulbous in female than in male, smooth dorsally and laterally. Ventral surface smooth except for a medial series of weak granules. Several long macrosetae on ventrolateral and ventral surfaces. Aculeus slightly shorter (♂) or about the same length (♀) as vesicle, moderately curved.

Pedipalps ( Figs. 29–90 ). Femur. Tetracarinate, ventrointernal, dorsointernal and dorsoexternal carinae strong, coarsely granulose, internal carina weak, granulose; external, ventroexternal and ventromedian carinae absent. Dorsal surface with dense, fine granulation, internal surface with dense (♂) or sparse (♀) fine granulation, ventral surface with sparse fine granulation (♂) or smooth (♀), external surface smooth dorsally and sparsely shagreened ventrally (♂), or entirely smooth (♀), with 7–9 distal external macrosetae. Patella. Tetracarinate, dorsomedian, dorsointernal and ventrointernal carinae strong, coarsely granulose; internal carina moderate (♂) or weak (♀), granulose; dorsomedian carina continuous in distal half (i.e., distal to trichobothrium d 3), marked by scattered granules (♂) or obsolete (♀) in proximal half. All intercarinal surfaces smooth. Chela. Slender, smooth, carinae obsolete except for digital carina on fixed finger. Sparse macrosetae on ventral manus and fixed finger. Fingers weakly curved, dentate margins of fixed and movable fingers armed with 8 non-imbricated rows of dentate granules, each row flanked proximally by one external and one internal accessory granule. Movable finger with 4 subterminal granules. Proximal dentate margins of fingers straight in both sexes. Trichobothriotaxy. Orthobothriotaxic, type A-b, pattern as characterized under diagnosis of the genus. For morphometric ratios, see diagnosis.

Legs ( Figs. 7–20 ). Femora I–IV with finely denticulate inferior carinae, granulate prosuperior carinae, crenulate retrosuperior carinae. Surfaces finely granulate, prolateral surfaces granulate, retrolateral surfaces smooth. Patellae I– IV with crenulate-granulate inferior, prolateral, prosuperior and retrosuperior carinae. Prolateral surfaces smooth or very weakly granular, retrolateral surfaces smooth. Series of several long macrosetae on inferior carinae, increasing in count for more posterior legs. Tibiae I–IV smooth, with long macrosetae. Tibial spurs present on legs III–IV, spurs larger on leg IV. Basitarsi I–III smooth, compressed, retrosuperior margins with dense, regular series of long macrosetae (bristle-combs), and 2 regular series of shorter macrosetae on retroinferior and proinferior margins. Basitarsus IV not compressed, with numerous macrosetae not arranged in regular series. Retrolateral basitarsal spurs on all legs simple, prolateral basitarsal spurs basally bifurcate. Telotarsi I–II with ventral macrosetae arranged in two regular (I) or irregular (II) rows. Telotarsi III–V with ventral macrosetae dense, long, irregular and not arranged in discrete rows. Tarsal ungues long, slender.

Measurements. See Table 1.

Variation. Color patterns were similar in all type specimens. Meristic and morphometric variation are summarized in Table 1 and under the species diagnosis.

AFFINITIES. The new species is differentiated morphologically from the type species, S. demisi , in having more robust pedipalps and metasoma. Comparative morphometric ratios (♂): S. sabae sp. n. (n = 3): metasoma II L/ W 1.33 –1.40, metasoma III L/ W 1.51 –1.53, metasoma IV L/ W 1.76 –1.83, and pedipalp patella L/ W 2.61 –2.66; S. demisi (holotype ♂): metasoma II L/ W 1.42, metasoma III L/ W 1.61, metasoma IV L/ W 1.94, and pedipalp patella L/ W 3.00.

DISTRIBUTION. Known only from the type locality ( Fig. 117 ).

Figures

Figures 1–4: Somalibuthus sabae sp. n., habitus. Figures 1–2. Male holotype in dorsal (1) and ventral (2) views. Figures 3–4. Female paratype in dorsal (3) and ventral (4) views. Scale bar: 10 mm.

Figures 5–16: Somalibuthus sabae sp. n. Figures 5–10. Holotype male. Carapace and tergites I–V (5), sternopectinal area and sternites (6), and left legs I–IV, retrolateral aspect (7–10). Figures 11–16. Paratype female. Carapace and tergites I–IV (11), sternopectinal area and sternites (12), and left legs I–IV, retrolateral aspect (13–16).

Figures 17–20: Somalibuthus sabae sp. n., carapace and tergites (17, 19) and coxosternal area and sternites (18, 20), under UV fluorescence. Figures 17–18. Paratype male. Figures 19–20. Paratype female. Scale bar: 2 mm (17–18, 19–20).

Figures 21–28: Somalibuthus sabae sp. n., chelicerae. Figures 21–24. Paratype male, right chelicera in dorsal (21–22) and ventral (23–24) views, under white light (21, 23) and UV fluorescence (22, 24). Figures 25–28. Paratype female, right chelicera in dorsal (25–26) and ventral (27–28) views, under white light (25, 27) and UV fluorescence (26, 28). Scale bars: 400 μm (21–24, 25–28).

Figures 29–48: Somalibuthus sabae sp. n., right pedipalp under white light. Figures 29–39. Holotype male, chela in dorsal (29), external (30) and ventral (31) views, patella in dorsal (32), external (33) and ventral (34) views, femur in ventral (35), internal (36) and dorsal (37) views, dentate margins of movable finger (38) and fixed finger (39). Figures 40–48. Paratype female, chela in dorsal (49), external (41) and ventral (42) views, patella in dorsal (43), external (44) and ventral (45) views, femur in ventral (46), internal (47) and dorsal (48) views.

Figures 49–60: Somalibuthus sabae sp. n., paratype male, right pedipalp under UV fluorescence. Figures 49–52. Chela in dorsal (49), external (50), ventral (51) and internal (52) views. Figures 53–56. Patella in dorsal (53), external (54), ventral (55) and internal (56) views. Figures 57–60. Femur and trochanter in dorsal (57), external (58), ventral (59) and internal (60) views. Scale bar: 2 mm.

Figures 61–72: Somalibuthus sabae sp. n., paratype female, right pedipalp under UV fluorescence. Figures 61–64. Chela in dorsal (61), external (62), ventral (63) and internal (64) views. Figures 65–68. Patella in dorsal (65), external (66), ventral (67) and internal (68) views. Figures 69–72. Femur and trochanter in dorsal (69), external (70), ventral (71) and internal (72) views. Scale bar: 2 mm.

Figures 73–90: Somalibuthus sabae sp. n., right pedipalp, trichobothrial maps and finger dentition.Figures 73–80. Paratype male trichobothria, chela in dorsal (73), external (74) and ventral (75) views. patella in dorsal (76) and external (77) views, femur in dorsal (78), external (79) and internal (80) views. Figures 81–82. Paratype female dentition of fixed (81) and movable (82) fingers. Figures 83–90. Paratype female trichobothria, chela in ventral (83), external (84) and dorsal (85) views. patella in external (86) and dorsal (87) views, femur in internal (88), external (89) and dorsal (90) views. Scale bars: 1 mm (73–80), 1 mm (81–82), 2 mm (83–90).

Figures 91–98: Somalibuthus sabae sp. n., metasoma and telson under white light. Figures 91–92. Telson in right lateral view of holotype male (91) and paratype female (92). Figures 93–95. Paratype female, metasoma and telson in right lateral (93), ventral (94) and dorsal (95) views. Figures 96–98. Holotype male, metasoma and telson in right lateral (96), ventral (97) and dorsal (98) views. Scale bars: 10 mm (93–95), 10 mm (96–98).

Figures 99–104: Somalibuthus sabae sp. n., metasoma and telson under UV fluorescence. Figures 99–101. Paratype male, metasoma and telson in dorsal (99), left lateral (100) and ventral (101) views. Figures 102–104. Paratype female, metasoma and telson in dorsal (102), left lateral (103) and ventral (103) views. Scale bars: 2 mm (99–101), 2 mm (102–104).

Figures 105–110: Somalibuthus sabae sp. n., right hemispermatophore, paratype male. Figures 105–107. Capsule in posterior (105), convex (106) and anterior (107) views. Figure 108. Capsule in convex view, compressed to show form of sperm hemiduct lobes. Figure 109. Whole hemispermatophore, convex view. Figure 110. Capsule in convex view, cross stereoscopic pair showing 3-dimensional structure. Scale bars: 200 μm (105–108), 1 mm (109), 200 μm (110).

Figures 116–117: Figure 116. Map showing type locality of Somalibuthus sabae sp. n. and S. demisi Kovařík, 1998. Figure 117. Type locality of Somalibuthus sabae sp. n.