Tityus spelaeus, Moreno-González 1 & Pinto-da-Rocha 1 & Gallão 2, 2021

Moreno-Gonzalez 1, Jairo A., Pinto-da-Rocha 1, Ricardo & Gallao 2, Jonas E., 2021, Bringing order to a complex system: phenotypic and genotypic evidence contribute to the taxonomy of Tityus (Scorpiones, Buthidae) and support the description of a new species, ZooKeys 1075, pp. 33-75 : 33

publication ID	https://dx.doi.org/10.3897/zookeys.1075.67459
publication LSID	lsid:zoobank.org:pub:BB034E5C-10CB-4917-9FCD-EF6A72816F6C
persistent identifier	https://treatment.plazi.org/id/3AE5D4E6-C2F1-47A7-9768-046B09B2FF48
taxon LSID	lsid:zoobank.org:act:3AE5D4E6-C2F1-47A7-9768-046B09B2FF48
treatment provided by	ZooKeys by Pensoft
scientific name	Tityus spelaeus
status	sp. nov.

Treatment

Tityus spelaeus sp. nov.

Figures 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Type material.

Brazil: State of Goiás: Holotype. Adult female from Posse, Russão II cave, 14°05'05.3"S, 46°23'07.1"W, 01.iv.2007, R. Pinto-da-Rocha leg. (MZSP 74633). Paratypes. Four adult female paratypes, same data as the holotype (MZSP 74634); eight adult females, same locality as the holotype, 23.iv.2015, J. E. Gallão & C. C. de Paula leg. (LES/UFSCar 14668; LES/UFSCar 14669; LES/UFSCar 14670; LES/UFSCar 14671; LES/UFSCar 14672; LES/UFSCar 14673); four adult females, same locality as the holotype, 01.iv.2007, R. Pinto-da-Rocha et al. (MZSP 52228, 52229, 52230, 52231).

Etymology.

The species epithet is a derivative form of the Greek noun, σπήλαιον (Latin: caverna), which means cave, in reference to the subterranean habitat where Tityus spelaeus has an established population. It is a noun in apposition.

Diagnosis.

(Based on female). This species belongs to the Tityus trivittatus species-group (Figs 2 View Figure 2 , 3 View Figure 3 ). Among members of the group distributed in Brazil ( T. carvalhoi Mello-Leitão, 1945; T. charreyroni Vellard, 1932; T. confluens Borelli, 1899; T. fasciolatus Pessoa, 1935; T. jeanvellardi Lourenço, 2001; T. karaja Lourenço, 2016; T. rupestre Lourenço, 2019; T. sylviae Lourenço, 2005, and T. trivittatus Kraepelin, 1898), Tityus spelaeus sp. nov. can be readily recognized. Tityus spelaeus sp. nov.; T. carvalhoi ; T. charreyroni ; T. confluens ; T. fasciolatus ; T. rupestre , and T. trivittatus share a subaculear tubercle small, and acute, pointing towards the tip of the aculeus (Fig. 12A View Figure 12 ). In contrast, T. jeanvellardi ; T. karaja , and T. sylviae exhibit a small and coarse subaculear tubercle that points either towards the tip of the aculeus ( T. sylviae ) or towards the middle of the aculeus ( T. jeanvellardi and T. karaja ).

On the other hand, Tityus spelaeus sp. nov. and T. sylviae share a very large glandular region occupying beyond the anterior two thirds of the medial region of the pectinal basal piece of female pectines (Figs 6E, F View Figure 6 , 11 View Figure 11 ). In T. carvalhoi ; T. charreyroni ; T. confluens ; T. fasciolatus , and T. trivittatus (females of T. jeanvellardi ; T. karaja and T. rupestre are unknow) the glandular region occupies a large area of anterior two thirds of the anteriomedian region of the pectinal basal piece of female pectines (e.g., Fig. 5A, B View Figure 5 ).

Finally, Tityus spelaeus sp. nov. and T. karaja can be readily distinguished from T. carvalhoi ; T. charreyroni ; T. fasciolatus ; T. jeanvellardi ; T. rupestre ; T. sylviae , and T. trivittatus , based on the presence of residual spots on tergites (Figs 7 View Figure 7 , 13 View Figure 13 ), and having the carapace (Figs 7 View Figure 7 , 8A View Figure 8 ) and chericeral manus immaculate (Fig. 8A View Figure 8 ). In contrast, T. charreyroni ; T. confluens ; T. fasciolatus ; T. jeanvellardi ; T. rupestre ; T. sylviae , and T. trivittatus have the carapace and tergites moderately covered with brownish spots and the cheliceral manus with reticulations (except T. jeanvellardi that exhibit a cheliceral manus immaculate).

Remarks.

In an unpublished comprehensive phylogenetic analysis of Tityus ( Moreno-González 2021), the Tityus trivittatus species-group was one of the most morphologically homogeneous species-groups of the genus. In fact, no somatic character of the morphological matrix (~164 chars) was optimized as a synapomorphy in the nodes within the clade representing the Tityus trivittatus species-group. Instead, those nodes were solely supported by unambiguous molecular synapomorphies. It is worth mentioning that, although coloration patterns presented high levels of homoplasy, they also showed significant differences at the species level, and the diagnosis of Tityus spelaeus sp. nov. is based on this background knowledge. Nonetheless, additional studies including molecular and phenotypical evidence of poorly described species from the Central region of Brazil are required to untangle the phylogeny of this cryptic species complex.

On the other hand, Tityus karaja Lourenço, 2016 was described based on a single male collected in 1929 in the region that corresponds to the northern portion of the state of Goiás, Brazil. According to the brief description of Lourenço (2016), Tityus karaja could share a similar body coloration pattern to that of T. spelaeus . However, given that the male of T. karaja is almost a hundred years old, the coloration needs to be corroborated with fresh specimens. Despite this, according to Lourenço’s (2016: fig. 5) illustration, the subaculear tubercle of T. karaja is conical, small, and coarse, pointing towards the middle of the aculeus, whereas in T. spelaeus sp. nov. it points towards the tip of the aculeus (Fig. 12A View Figure 12 ).

Description.

Based on the female holotype (MZSP 74633). Male unknown.

Total length. Female: 53.52 mm (measurements in Table 4 View Table 4 ).

Coloration.

General pattern (in ethanol 70%) (Fig. 7 View Figure 7 ): light yellow, without variegated pigmentation. Carapace (Figs 7A View Figure 7 , 8A View Figure 8 ): light yellow; lateral and median eyes, surrounded by black variegated pigments. Chelicerae (Figs 7A View Figure 7 , 8A View Figure 8 ): coxa and hand light yellow, without pigments; fingers, dark reddish-brown. Mesosoma, coxosternal region, pedipalps, legs (Fig. 7A, B View Figure 7 ): all light yellow. Metasoma (Fig. 7A, B View Figure 7 ): segments light yellow, progressively becoming darker towards the telson. Telson (Fig. 7A, B View Figure 7 ): dark yellow; aculeus dark reddish-brown. Live coloration pattern (Fig. 13A-C View Figure 13 ) similar to that of preserved specimens, except for mesosoma with a faint brown median stripe crossing all tergites, telson light reddish-brown, pedipalp chela fingers and metasomal segments IV-V dark reddish-brown.

Morphology.

Carapace (Fig. 2B View Figure 2 ): densely covered with fine granulation and few coarse granules; anterior margin with deep median notch; anterior median carinae only feebly marked over anterior 1/3; central lateral, central median, lateral ocular, posterior, posterior median and superciliary carinae, all well-marked; and furrows (anterior median, anterior marginal, central transverse, lateral ocular, supercialiary, posterior transverse, posterior lateral and posterior marginal), all well-marked; ocular tubercle well-marked, located on the anterior half of carapace; median eyes separated by about 0.53 ocular diameters; with three pairs of lateral eyes and two pairs of lateral micro-ocelli.

Chelicerae (Fig. 8B View Figure 8 ): dentition characteristic of the family Buthidae ( Vachon 1963), densely covered with setae over the internal and ventral surfaces.

Pedipalps: Chela, short and slender (female, L/W= 5.5). Orthobothriotaxic pattern Type A, femur with alfa configuration (hand: Eb3:Eb2:Eb1:Esb:Est:Et, fixed finger: eb:esb:est:et:db:dt:it). Femur (Fig. 9A View Figure 9 ) with five carinae: VI, DI, DE, and VE crenulate, EM serratocrenulate, complete and pronounced, with intercarinal areas densely covered with fine granulation and few coarse granules. Patella (Fig. 9B, C View Figure 9 ) with seven carinae: VI, VE, DI, DE, and EM complete and crenulate; DM incomplete and crenulate; IM complete and serratocrenulate, with a short spiniform granule near the segment base; with intercarinal areas densely covered with fine granulation. Chela (tibia) (Fig. 10A-C View Figure 10 ) with eight carinae: VI, VE, D, DS, DMA, IM, and ES, complete and crenulate; SA, incomplete and crenulate, only present on the anterior half of the hand. Pedipalp movable and fixed fingers without basal lobe (Fig. 10A View Figure 10 ). Movable finger with 17-17 rows.

Coxosternal region (Fig. 7B View Figure 7 ): Sternum with posterior depression, outer ridge, and apical button, well-marked; sclerite covered with fine granulation, and few setae, except for the coxapophyses I-II, which are smooth; genital operculum longitudinally divided, composed of two sub-triangular plates.

Pectines (Fig. 11 View Figure 11 ). Pectinal basal piece sub-rectangular and covered with a large and raised glandular region occupying beyond the anterior two thirds of the anteromedian region (Figs 6E, F View Figure 6 , 11A, B View Figure 11 ; Table 3 View Table 3 ); pectinal tooth count of 19-22. Marginal lamellae, median lamellae, and fulcra moderately covered with setae (Fig. 5C View Figure 5 ). Basal middle lamellae, not dilated (Figs 6E, F View Figure 6 , 11C View Figure 11 ). Pectinal tooth peg sensillae rectangular in cross-section, with a narrow distal openning (Fig. 11D, E View Figure 11 ).

Legs: Carinae present; intercarinal areas with sparse fine granulation; ventral telotarsal macrosetae acute and fine, arranged in two ventrosubmedian rows (Fig. 4K, L View Figure 4 ); telotarsi, counts of ventral macrosetae in the left (L) and right (R) legs on prolateral (pro) and retrolateral (retro) rows of legs I to IV (L (pro/retro) R (pro/retro)): 7/6 7/7: 7/7 7/7: 9/8 9/10: 10/10 9/11. Claws short and symmetrical.

Mesosoma: Tergites I-VI, moderately covered with fine granulation and few coarse granules; pre-tergites well defined, with median carina visible on the posterior margin of the post-tergites; tergite VII with DSM and DL carinae complete and crenulate, and median carina composed of a crenulate anteromedian eminence present on the anterior half of the post-tergite. Sternites densely covered with fine granulation; sternites III-VI with a pair of elliptic spiracles on the posterior half, which are progressively larger; sternite V with a hyaline subtriangular area on the posterior margin; sternite VI with VSM carinae crenulate, present on posterior half; sternite VII with VSM and VL carinae crenulate, present on posterior two thirds.

Metasoma (Fig. 12C, D View Figure 12 ): Segments II-V short and robust (L/W ratio: II= 1.9; III= 1.9; IV= 2.0; V= 2.5); segment V not incrassate (Fig. 12C View Figure 12 ). Segments I-II (Fig. 12C, D View Figure 12 ) with 10 complete carinae, parallel to one another and crenulate (paired DSM, DL, ML, VL, and VSM), ML of segment II represented by coarse granules on posterior two thirds, intercarinal areas densely covered with fine granulation; segments III-IV (Fig. 12C, D View Figure 12 ) with eight complete carinae, parallel to one another and crenulate (paired DSM, DL, VL, and VSM), intercarinal areas densely covered with fine granulation; segment V (Fig. 12C, D View Figure 12 ) with five complete carinae, crenulate (VM, paired DSM, and VL: DSM carinae feebly marked), intercarinal areas moderately covered with fine granulation and few coarse granules. Segments II-IV (Fig. 12C View Figure 12 ) with DSM carinae feebly marked, composed of evenly sized granules, without enlarged distoterminal granule.

Metasomal macrosetae: Segments I-IV each with two pairs of VSM macrosetae (2/2): pair of VSM1 located on the anterior third, and pair of VSM2 located near posterior margin of segment; and with two pairs of VL macrosetae (2/2): pair of VL1 located near anterior margin of segment, and pair of VL2 located on posterior two thirds of segment. Segment V with two pairs of VSM macrosetae (2/2), two pairs of VL macrosetae (2/2), and a single pair of ML macrosetae (1/1); pairs of VSM1 and VL1 located near anterior margin of segment; pair of VL2 located on posterior two thirds of segment, and pair of ML1 located dorsolaterally behind the DSM carinae near posterior margin of segment; anal arch with two pairs of setae on the intercrestal area: one pair of VSM macrosetae (1/1) and one pair of VL macrosetae (1/1).

Telson (Fig. 12A, B View Figure 12 ): Vesicle suboval, not elongated (L/H= 1.8), dorsal surface smooth, lateral surfaces with shallow longitudinal furrow; with VM, paired VSM, VL, and DL carinae, vestigial. Subaculear tubercle large, conical, with spiniform apex directed towards the distal region of the aculeus (Fig. 12A View Figure 12 ); subaculear tubercle with ventral pair of small, rounded granules, pointing towards the basal portion of the aculeus; aculeus strongly curved, shorter than vesicle and with ventral groove.

Variability (females).

Morphometrics. Total length (including telson): 48.30-57.98 mm (n= 17, mean= 52.70, standard deviation (SD)= 2.66). Chela L/W ratio: 4.42-5.78 (n= 17, mean= 5.44, SD= 0.37). Metasomal segment I L/W ratio: 1.24-1.51 (n= 17, mean= 1.30, SD= 0.06). Metasomal segment V L/W ratio: 2.31-2.68 (n= 17, mean 2.52, SD= 0.12). Telson vesicle L/H: 1.63-1.89 (n= 17, mean= 1.76, SD= 0.09). Meristics. Pectinal tooth count: 19-22 (n= 34, mode= 20). Number of movable finger oblique granular rows: 16-18 (n= 34, mode= 18). Metasomal macrosetae count: (n= 17): 2/2 VSM and 2/2 VL macrosetae on segments I-IV, 3/3 VSM and 2/2 VL macrosetae on segment V. However, one specimen (LES/UFSCar 14668) lost VSM1 on segment II, a second specimen (LES/UFSCAR 14669) lost VL1 on segment II, and a third specimen (LES/UFSCAR 014673) lost one VSM1 on segment I. Variation in the count of telotarsal ventrosubmedian setae is presented in Table 5 View Table 5 .

Natural history.

Russão II cave is formed by limestone (a karstified type of rock), located in Posse municipality, the northeastern state of Goiás, Central Brazil. This karst region is part of the Bambuí geomorphological group, the large geomorphological group in Brazil, occurring in states of Bahia, Goiás, Minas Gerais, and Tocantins. Russão II cave is inserted on the Cerrado morphoclimatic domain ( Ab’Saber 1977), and the climate is tropical semi-humid ( Nimer 1979). There is a stream crossing the cave although there are no surface drainages nearby ( Tencatt and Bichuette 2017). Russão II cave is located on private property, and in addition surface habitats are under impact from pollution through the discharge of domestic sewage, deforestation of surroundings for cattle pasture, and small mining projects ( Tencatt and Bichuette 2017). Russão II cave, like other caves in the region, has no legal protection under Brazilian environmental laws. The cave has a significant amount of bat guano piles and a large cricket population that is preyed upon by scorpions. In the aphotic zone of Russão II cave, the temperature was 30.04 °C, the relative humidity of the air was 72.02%.

This species was studied in the past by Outeda-Jorge et al. (2009) who reported a litter size of two scorpionlings, but under laboratory conditions (Fig. 13A-C View Figure 13 ), another two females had a litter of four scorpionlings, and both females were fed upon their litter (Fig. 13A, B View Figure 13 ). The population of Tityus spelaeus sp. nov. at the Russão cave is well-established (Fig. 8A, B View Figure 8 ). During a one-hour-long visit to the cave in 2007, more than 20 live scorpions were observed on the ground and walls (Fig. 14A, B View Figure 14 ). In another two-hour visit in 2015, 32 individuals were counted, both adults and juveniles.