Troglotayosicus akaido, Moreno-González & Luna-Sarmiento & Prendini, 2024

Moreno-González, Jairo A., Luna-Sarmiento, David A. & Prendini, Lorenzo, 2024, Phylogeny of the Troglomorphic Scorpion Genus Troglotayosicus (Scorpiones: Troglotayosicidae) with Description of a New Species from Colombia, American Museum Novitates 2024 (4011), pp. 1-40 : 11-22

Troglotayosicus akaido , sp. nov.

Figures 1 , 2 , 3 , 4A–D , 5A–F , 6A, B , 7A–H, 8A–H, 9A–H,

10A, B, 11A–F, 12A–F, 13A, B, 14A–D; tables 1, 2

TYPE MATERIAL: COLOMBIA: Amazonas Department: El Encanto Municipality: Río Caraparaná, Comunidad de San Rafael , 01°41 ' 10.5 ̎ S 73°13 ' 18.7 ̎ W, 123 m, 23–24.iv.2022, D. Luna and G. Cobette, holotype Ƌ, 2 Ƌ, 2 ♀, 2 subad. ♀, 1 juv. paratypes ( ICN).

DIAGNOSIS: Troglotayosicus akaido , sp. nov., shares with T. ballvei , T. hirsutus , T. humiculum , and T. meijdeni the regular distribution of ventral macrosetae on the telotarsi into two ventrosubmedian rows, di ering in this respect from T. muranunkae and T. vachoni , in which the ventral macrosetae on the telotarsi are irregularly distributed. ffle tegument is moderately setose in T. akaido (g. 4A–D), T. ballvei , T. humiculum , T. meijdeni , T. muranunkae , and T. vachoni , unlike in T.hirsutus , in which the tegument is densely setose ( Botero-Trujillo et al., 2012: 69, gs. 8–11). Trichobothrium D 1 (Db) is situated proximally on the pedipalp chela manus, and slightly distal to trichobothrium Eb 3 in T. akaido (g. 9B), T. ballvei , T. humiculum , T.hirsutus , T. meijdeni , and T. vachoni , but situated submedially on the manus, between trichobothria Eb 3 and d 8 (db) in T. muranunkae ( Sánchez-Vialas et al., 2020: 616, g. 5A). Trichobothrium i 3 (it) is situated midway between trichobothrium i 4 (ib) and the base of the chela xed nger in T. akaido (g. 9H), but closer to the base of the xed nger than to trichobothrium i 4 (ib) in all other species of the genus. ffle pedipalp chela exhibits distinct sexual dimorphism, with a more incrassate manus in the adult males of T. akaido (g. 8A, C, E, G), T.hirsutus , T. humiculum , and T. vachoni , whereas the chela shape is similar in the adults of both sexes in T. ballvei ( Botero-Trujillo et al., 2021: 12, g. 8A–D) (the adult male is unknown in T. meijdeni and T. muranunkae ). ffle VSM and VL carinae of metasomal segment IV are incomplete and reduced to scattered granules in the anterior half of the ventral surface in T. akaido (g. 11C, F), T. ballvei , and T. vachoni , whereas these carinae are complete in T. humiculum ( Ochoa et al., 2010: 12, 13, gs. 9C, 10C), and absent in T.hirsutus ( Botero-Trujillo et al., 2012: 73, g. 24), T. meijdeni , and T. muranunkae . ffle VSM and VL carinae of metasomal segment V are complete in T. akaido (g. 12C, F), T. ballvei , T. humiculum , and T. vachoni , whereas these carinae are partial, reduced to the posterior two-thirds of the segment in T. hirsutus ( Botero-Trujillo et al., 2012: 73, g. 24), T. meijdeni , and T. muranunkae .

Troglotayosicus akaido di ers further in the absence of a lateral eyespot (g. 5C, F) and in the position of trichobothrium e 8 (Et 4), which is situated distal to trichobothrium m 4 (dsb) on the pedipalp chela manus (g. 9D); in all other species of the genus, the lateral eyespot is present and trichobothrium e 8 (Et 4) is situated proximal to trichobothrium m 4 (dsb).

ETYMOLOGY: Named a er the word akaìdo , which means “scorpion” in the Huitoto Murui language. ffle Murui people live in the vicinity of the type locality.

DESCRIPTION: Based on the holotype Ƌ ( ICN) (g. 2) and paratype ♀ ( ICN). Total length: male, 19.53 mm; female 18.44 mm (table 2) .

Coloration: General pattern (in 70% ethanol) reddish brown (g. 4A–D). Carapace (g. 5A–C), pedipalps, and tergites uniformly reddish brown, with carapacial sulci less pigmented and lateral ocelli surrounded by black spots. Chelicerae, coxosternal region, legs, and sternites uniformly light reddish brown. Metasomal segments dark reddish brown, becoming progressively darker posteriorly. Telson reddish brown; aculeus black.

Chelicerae: Manus dorsal and retrolateral surfaces smooth, sparsely covered with setae; prolateral and ventral surfaces densely covered with setae. Fixed nger with four dorsal teeth (distal, subdistal, median, and basal); median and basal teeth separate, not fused into bicusp; teeth progressively increasing in size distally. Movable nger with ve dorsal teeth (prodistal, two small subdistal, median, and basal); teeth progressively increasing in size distally, except for subdistal teeth that are smaller than median and basal teeth; prodistal and retrodistal teeth not opposable; ventral surface with long, well-developed serrula, and vestigial retrobasal denticle.

Carapace: Surfaces sparsely covered with coarse granules and few fine granules (fig. 5A–F); anterior margin with round, slightly protruding epistome; lateral ocular carinae, central lateral carinae, and posterior median carinae distinct, other carinae absent; lateral ocular sulci, central transverse sulcus, posterior lateral sulci, and posterior transverse sulcus distinct; median ocelli absent; two pairs of lateral ocelli (PDMi and PLMa) (Type 2B); eyespot absent.

Sternum: Shape subpentagonal with rounded apex (fig. 6A, B); posterior depression shallow, sparsely setose on median surface and with many microsetae along anterior margin.

Pectines: Pectinal plate sexually FIGURE 7. Troglotayosicus akaido , sp. nov., dextral pedidimorphic (g. 6A, B), 1.8× wider than palp femur, dorsal aspect (A, B), and patella, dorsal (C,

D), retrolateral (E, F), and ventral (G, H) aspects. A, C, long and square (Ƌ) or 2.2× wider than E, G. Holotype Ƌ ( ICN). B, D, F, H. Paratype ♀ ( ICN). long and rectangular (♀); densely (Ƌ) or Scale bar: 0.7 mm. sparsely (♀) setose. Pectinal tooth count 7/7 (Ƌ, ♀), teeth longer and wider in Ƌ; teeth, medial and marginal lamellae densely setose .

Pedipalps: Femur with three (♀) or ve (Ƌ) carinae (g. 7A, B); PD, RD, and PM carinae crenulate and complete; PV and RV carinae restricted to proximal third (Ƌ) or absent (♀); dorsomedian and proventral surfaces sparsely and coarsely granular; prodorsal surface sparsely and nely granular; retrodorsal and retroventral surfaces smooth; ventral surface smooth (♀) or sparsely and coarsely granular in proximal third (Ƌ). Patella with two carinae (g. 7C–H); PD and PV carinae crenulate and restricted to proximal third; DPP composed of three or four coarse granules; all surfaces smooth. Chela manus (tibia) broader in Ƌ (L/W, 2.63; L/H, 2.28) than in ♀ (L/W, 2.72; L/H, 2.29) (g. 8A–H). Manus with seven obsolete carinae; DS, DI, RL, RV, and PV carinae smooth; DMA carina granular along entire length (Ƌ) or only in distal half (♀); PD carina granular; intercarinal surfaces smooth and setose along carinae. Fixed and movable ngers without lobes or depressions; prolateral and retrolateral surfaces densely setose; xed nger with six oblique, slightly imbricate rows of denticles, anked by six prolateral and ve retrolateral denticles, terminal denticle enlarged; movable nger with seven oblique, slightly imbricate rows of denticles, anked by seven prolateral and six retrolateral denticles, terminal denticle enlarged.

Trichobothria: Femur with three trichobothria (g. 9A): one each on retrolateral (d 5 [e]), dorsal (d 3 [d]), and prolateral (i 1 [i]) surfaces. Patella with 19 trichobothria (g. 9C, E, G): two on ventral surface (V 1, V 3 [V 2]); 14 on retrolateral surface (et 9 [et 1], et 3 [et 2], V 4 [et 3], est 1 [est], em 1, et 6 [em 2], em 4 [em 3], esb 1, esb 4 [esb 2], eb 2 [eb 1], eb 3 [eb 2], eb 4 [eb 3], eb 5 [eb 4], eb 9 [eb 5]), including two petite (est 1 [est], esb 4 [esb 2]) and one accessory (em 4 [em 3]); two on dorsal surface (d 1, d 2); and one on prolateral surface (i 1 [i]). Chela manus with 26 trichobothria (g. 9B, D, F, H): 15 on manus, four on ventral surface (V 1, i 5 [V 2], V 3, V 5 [V 4]), ten on retrolateral surface (Et 1, Et 2, Est 4 [Et 3], e 8 [Et 4], Est 6 [Et 5], Est 3 [Est], Esb 1 [Esb], Eb 1 – Eb 3), and one on dorsal surface (D 1 [Db]); and 11 on xed nger, four on retrolateral surface (e 3 [et], e 5 [est], e 6 [esb], Et 6 [eb]), ve on dorsal surface (d 4 [dt], m 2 [dst], m 3 [dm], m 4 [dsb], d 8 [db]), and two on prolateral surface (i 3 [it], i 4 [ib]).

Tergites: Pretergites smooth; posttergites smooth in anterolateral half, granular posteromedially and posterolaterally; posttergite VII with lateral carina granular, terminating in enlarged granule, median and submedian surfaces coarsely granular.

Sternites: Surfaces smooth; ventral surface sparsely setose, lateral and posterior margins densely setose (g. 10A, B). Book lung spiracles subcircular.

Legs: Legs I – IV with carinae more developed on III and IV than on I and II. Femur tricarinate (less pronounced in ♀), RV and PM carinae continuous, granular, PD carina restricted to proximal third, fused with RV carina medially. Tibia sparsely setose, tibial spurs absent. Basitarsi of legs I– IV setose, each with dorsal and ventral rows of comblike macrosetae distally; dorsal retrolateral comb present, well developed on legs I– IV, but shorter on I and II; ventral prolateral comb present on I– III, absent on IV; prolateral pedal spurs present; retrolateral pedal spurs vestigial. Telotarsi I – IV, dorsomedian lobe with one macroseta; ventral surface without spinules, subspiniform macrosetae regularly arranged into pair of parallel ventrosubmedian rows. Telotarsi, counts of macrosetae in proventral and retroventral rows of sinistral (S) and dextral (D) legs I– IV (proventral S–D/retroventral S–D): Ƌ, 6–5/7–7, 6–6/8–6, 7–?/9–?, 9–9/8– 8; ♀, 7–6/5–4, 6–6/9–7, 7–6/8–8,?–?/?–?; ungues short, symmetric .

Metasoma: Segments I–V progressively increasing in length (gs. 11A–F, 12A–F). Segments I–V, dorsal intercarinal surfaces smooth; lateral intercarinal surfaces sparsely granular; ventral intercarinal surfaces smooth on I–III, coarsely granular in posterior half of IV. Segment V, dorsal intercarinal surface smooth; lateral surfaces entirely coarsely and densely granular, ventral surface coarsely and densely granular in posterior half. DL carinae complete, serrato-crenulate, converging posteriorly on segments I–IV; complete, crenulate on V; LSM carinae obsolete, partial, each comprising row of granules between DL and ML carinae, in posterior half of segments I–IV; ML carinae complete, serrato-crenulate on segments I–IV, complete but obscured by coarse granulation on V; LIM carinae obsolete, comprising isolated granules, complete on segment I, restricted to posterior two-thirds on II–IV and to anterior half on V; VL and VSM carinae absent on segments I–III, consisting of discontinuous, coarse granules in medial third of IV; VSM and VM carinae absent on segments I–IV, present but obscured by coarse granulation on V.

Telson : Vesicle suboval, elongate (g. 13A, B), narrower in Ƌ (L/H, 3.63) than in ♀ (L/W, 2.93) (table 2); anterodorsal lateral lobes present; dorsal and dorsolateral surfaces smooth; ventral and ventrolateral surfaces smooth (Ƌ) or with three sparsely granular rows (obsolete VM and VSM carinae) anteriorly (♀) and numerous macro- and microsetae. Aculeus long, stout basally.

Hemispermatophore: Shape lamelliform (g. 14A–

D). Lamina translucent and weakly sclerotized, broad proximally and medially, and progressively tapering distally; crests absent; apex elongate, strongly recurved.

Capsular region simple; external lobe (EL) medium sized, inclined ventrally; internal lobe (IL) medium sized, thick, with dorsal process, inclined entally; IL cylindrical, elongate, slightly larger than EL, with sclerotized spurlike projection directed ventrally; median lobe absent. Foot exure present, trunk well developed, FIGURE 13. Troglotayosicus akaido , sp. nov.,

weakly sclerotized, twice as broad as basal portion of telson, lateral aspect. A. Holotype Ƌ ( ICN). B. Paratype ♀ ( ICN). Scale bar: 1 mm. lamina .

VARIATION: Total length: Ƌ, 15.03–19.53 mm (n =

3; table 2), ♀, 16.17–18.44 mm (n = 2). Telotarsi ventral macrosetal rows: 6 or 7 prolateral and

5 to 9 retroventral macrosetae on leg I, 6 to 8 proventral and 6 to 8 retroventral on leg II, 7 to

9 proventral and 9 or 10 retroventral on leg III, and 7 to 9 proventral and 8 to 10 retroventral on leg IV (Ƌ) (n = 3; table 2); 5 to 7 prolateral and 4 to 6 retroventral macrosetae on leg I, 6

to 9 proventral and 5 to 7 retroventral on leg II, 7 to 9 proventral and 6 to 8 retroventral on leg III, and 7 or 8 proventral and 9 or 10 retroventral on leg IV (♀) (n = 2; table 2).

DISTRIBUTION: Known only from the type locality, Río Caraparaná, in the El Encanto

Municipality of the Amazonas Department of Colombia (g. 1).

NATURAL HISTORY: ffle specimens of T. akaido were collected in a secondary tropical terra rme rainforest at elevations of 123 to 150 m. Adults were found under a deep layer of leaf litter, 10 to 25 cm below the surface. Some juveniles were found closer to the surface in the leaf litter. One juvenile was collected in a disturbed forest near the Chagra ecosystem. fflis species was sympatric with four other scorpion species, Ananteris sp. , Chactopsis sp. , Tityus bastosi

Lourenço, 1984, and Tityus sp.

SCORPIONISM: ffle second author was stung on the right thumb during collection of the male holotype. Intense pain, without paralysis or thermal sensation, was experienced for 30

minutes a er envenomation, followed by local redness and in ammation. ffle a ected area developed hyperkeratosis a er three or four days. No other symptoms were experienced.

ADDITIONAL MATERIAL EXAMINED: COLOMBIA: Amazonas Department: El Encanto

Municipality: Río Caraparaná, Comunidad de San Rafael, 01°41 ' 10.5 ̎ S 73°13 ' 18.7 ̎ W, 150 m,

23.iv.2022, D. Luna, manual collecting using UV light, inside leaf litter, 30 cm deep, 2 juv.

(AMCC [LP 18087, 18093]).

Figures

FIGURE 1. Known locality records of the species of Troglotayosicus Lourenço, 1981, in Colombia and Ecuador: (1) Troglotayosicus vachoni Lourenço, 1981; (2) Troglotayosicus humiculum Botero-Trujillo and Francke, 2009; (3) Troglotayosicus hirsutus Botero-Trujillo et al., 2012; (4) Troglotayosicus meijdeni Botero-Trujillo et al., 2017; (5) Troglotayosicus muranunkae Lourenço et al., 2020; (6) Troglotayosicus ballvei Botero-Trujillo et al., 2021; (7) Troglotayosicus akaido, sp. nov.

FIGURE 2. Troglotayosicus akaido, sp. nov., live habitus, holotype Ƌ (ICN). A. Anterior aspect. B. Lateral aspect.

FIGURE 3. Phylogeny of Troglotayosicus Lourenço, 1981, based on maximum likelihood analysis of 131 morphological characters (appendices 2, 3). Unambiguous character states optimized and plotted on branches. Black circles indicate uniquely derived apomorphic states, white circles parallel derivations of apomorphic states. Numbers above branches correspond to character numbers; numbers below branches to character states (appendix 3); numbers at nodes indicate ultrafast bootstrap values.

FIGURE 4. Troglotayosicus akaido, sp. nov., habitus, dorsal (A, C) and ventral (B, D) aspects. A, B. Holotype Ƌ (ICN). C, D. Paratype ♀ (ICN). Scale bars: 10 mm.

FIGURE 5. Troglotayosicus akaido, sp. nov., carapace, dorsal aspect, under white light (A, B) and UV light (D, E) and lateral ocelli under white light (C) and UV light (F). A, D. Holotype Ƌ (ICN). B, C, E, F. Paratype ♀ (ICN). Scale bars: 2 mm (A, B, D, E); 0.6 mm (C, F).

FIGURE 6. Troglotayosicus akaido, sp. nov., coxosternal region and pectines, ventral aspect. A. Holotype Ƌ (ICN). B. Paratype ♀ (ICN). Scale bars: 1.5 mm.