Tityus pictus Pocock, 1893

Teruel, Rolando, 2011, Redescription of Tityus pictus Pocock, 1893 and Tityus smithii Pocock, 1893, with notes on the Tityus species from the Lesser Antilles (Scorpiones: Buthidae), Euscorpius 125 (125), pp. 1-26 : 2-7

publication ID	https://doi.org/ 10.18590/euscorpius.2011.vol2011.iss125.1
publication LSID	lsid:zoobank.org:pub:9D2D308A-1B79-45AF-A2C0-95AEFCE38E5B
persistent identifier	https://treatment.plazi.org/id/59771773-123C-FFB1-FEB6-FBD0667DF8E6
treatment provided by	Felipe
scientific name	Tityus pictus Pocock, 1893
status

Treatment

Tityus pictus Pocock, 1893 View in CoL

Figs. 1–3 View Figure 1 View Figure 2 View Figure 3 , 14 View Figure 14 , Tabs. 1–2, 5–7

Tityus pictus Pocock, 1893: 377 View in CoL , 382–384, 409, pl. XXX, figs. 8–8a; Kraepelin, 1899: 75, 86; Mello-Leitão, 1931: 126, 143; Mello-Leitão, 1939: 60–61, 65, 74, tab. IIc; Armas, 1982: 6, tab. 2 (in part: record from St. Vincent only); Lourenço, 1984: 91–92, 97–102, 104, figs. 20–27, tab. I (in part: specimens and record from St. Vincent only); Armas, 1988: 93 (in part: record from St. Vincent only); Lourenço, 1992: 45; fig. 1 (in part: record from St. Vincent only); Lourenço, 1995: 28, fig. 1 (in part: record from St. Vincent only); Kovařík, 1998: 122 (in part); Fet & Lowe, 2000: 230, 255–256; Lourenço, 2006: 60.

Tityus pictus pictus View in CoL : Mello-Leitão, 1945: 310; Lourenço, 1984: 97–99, tab. I; Armas, 1988: 80–81; Fet & Lowe, 2000: 256; Lourenço, 2006: 60.

Diagnosis: species of medium size (males 47–65 mm, female 51–54 mm) for the genus. Body light yellowish brown, with a moderately dense pattern of dark brown spots; tergites with three well-defined but irregular dark stripes; pedipalp fingers, metasomal segments IV–V and telson blackish. Pedipalp chela elongate and incrassate in males, oval in females. Sternite V with an inconspicuous smooth patch in males. Metasoma conspicuously attenuate and only slightly enlarged distally in males, with all carinae very weak to moderate and finely subcostate to serrato-crenulate; dorsolateral carinae of metasomal segments II–IV with distal tooth not enlarged. Telson inflate and coriaceous; subaculear tubercle vestigial. Pedipalp fixed finger with 13 principal rows of granules, movable finger with 14–15; basal lobe/notch combination strong in males, moderate in females. Pectines with 20–21 teeth in males, and 18–21 in females; basal middle lamella obtusely angulose and slightly dilated in males, rounded and strongly dilated in females.

Type data: 2 adult ♂♂ and 3 adult ♀♀ syntypes ( BMNH: 1894.10.14.21–25; not examined): St. Vincent; commonly found on Bromeliae, on trees Coneralid at the bases of leaves, rare in houses or under bark; H. H. Smith coll. Note: see Remarks for a detailed discussion on this topic .

Distribution ( Fig. 14 View Figure 14 ): this species has been collected only at St. Vincent, and it appears to be endemic from this island.

Redescription (adult male topotype): Coloration ( Figs. 1–2 View Figure 1 View Figure 2 ) basically light yellowish brown, irregularly spotted with medium to dark brown all over the body and appendages; spots lighter (pale to light brown) on pedipalps, metasomal segments I–III and venter. Chelicerae densely reticulated with blackish brown all over the manus; fingers blackish. Pedipalps diffusely spotted with light brown; fingers blackish. Carapace with interocular area densely infuscate; tergites with three well-defined dark stripes, composed of reticulate to irregular spots; coxosternal region immaculate; pectines pale yellowish, immaculate; sternites irregularly spotted, almost immaculate mesially. Legs densely spotted with light brown. Metasomal segments I–III very diffusely spotted with pale brown on all surfaces, segments IV–V and telson blackish. Carapace ( Fig. 2a View Figure 2 ) trapezoidal, anterior margin very widely V-shaped; anterior median, superciliary, central median and posterior median carinae finely granulose (the latter fused into irregular rows), other carinae obsolete to absent; tegument finely and densely granulose, with coarser granules scattered; median eyes separated by more than one ocular diameter; three pairs of lateral eyes, which are all a little smaller than median eyes. Tergites ( Fig. 2a View Figure 2 ) with the same granular sculpture as on carapace; longitudinal carina well defined and finely granulose; VII with two pairs of finely serrate lateral carinae. Chelicerae ( Fig. 2a View Figure 2 ) with dentition typical for the genus; tegument smooth and shiny. Pedipalps ( Figs. 1a–b View Figure 1 , 2b View Figure 2 ) orthobothriotaxic A-α. Femur with all carinae finely granulose; intercarinal tegument very finely and densely granulose. Patella with all carinae finely granulose to subgranulose; intercarinal tegument with the same granular sculpture as on femur, internal surface with several conical granules. Chela elongate and incrassate, noticeably wider than patella ( Tabs. 1, 2, 5); hand with nine carinae, all moderate and very finely subgranulose to costate, intercarinal tegument (Wp), depth (H), not measured (–). Data of BMNH specimens from Lourenço (1984: tab. I).

coriaceous to very finely and densely granulose; fingers with basal lobe/notch combination strong, fixed finger with 13/13 principal rows of granules, movable finger with 14/15, apical subrow composed by four granules aligned similar to principal rows. Legs ( Figs. 1a–b View Figure 1 ) with all carinae subcostate to granulose; intercarinal tegument very finely and densely granulose. Sternum ( Fig. 2c View Figure 2 ) type 1, markedly pentagonal. Pectines ( Fig. 2c View Figure 2 ) somewhat small, just reaching the coxa-trochanter joint of leg IV; pectinal tooth count 20/20; basal middle lamella obtusely angulose and slightly dilated. Sternites ( Figs. 2c–d View Figure 2 ) with oval-elongate spiracles; sternite III with the lateral areas slightly depressed and very finely granulose, mesially smooth, IV–VI essentially smooth, VII finely and densely granulose; posterior margin of sternite V with a large and smooth patch, which is whitish, subtriangular, much wider than long and moderately bulky; sternites VI–VII with two pairs of granulose lateral carinae. Metasoma ( Figs. 2e–g View Figure 2 ) markedly elongate but slightly enlarged distally; intercarinal tegument coriaceous, with small granules scattered; segment I with ten complete carinae, II–IV with eight (even though the lateral inframedian carinae are present on distal third of II), V with five, all moderately developed and finely subcostate to serrato-crenulate; dorsolateral carinae on II–IV with the distal tooth not enlarged; telson oval in lateral view, vesicle inflate and coriaceous, with a subgranulose ventromedian carina progressively elevated towards the subaculear tubercle, which is very small, conical, placed close to the base of aculeus and lacks any granules; aculeus short, sharp and evenly curved.

Female (juvenile topotype, adult data taken from Pocock [1893] and Lourenço [1984]. Tabs. 1–2, 5–7): in general similar to the male, but there is a strong sexual dimorphism evidenced by: (1) mesosoma relatively wider; (2) metasoma shorter and stouter; (3) pedipalp chela much smaller, short-oval in shape and narrower than patella; (4) pedipalp fingers with basal lobe/notch combination weaker; (5) pectines with lower tooth counts, and basal middle lamella oval and strongly dilated.

Variation: the adult size of T. pictus varies from 46.5–64.7 mm in males, and 50.9–54.0 mm in females ( Tab. 1). Pocock (1893) recorded 63.5 mm (male) and 54 mm (female) for two syntypes, Lourenço (1984) measured another pair of syntypes with lengths of 46.5 mm (male) and 50.9 mm (female), and the topotype male herein examined has a size of 64.7 mm; these data suggest that there are two different size classes in males, but only one in females.

The small male syntype measured by Lourenço (1984) also exhibits less marked sexual dimorphism when compared to the large males: pedipalp chela less incrassate and metasomal segments shorter and less slender ( Tabs. 1–2). This progressive size-related gradation on the expression of dimorphic characters has already been documented for many other species of this genus (Lourenço, 1983; Armas et al., 2002; Montoya & Armas, 2002; Kovařík, 2007; Teruel & Armas, 2006; Rojas-Runjaic & Armas, 2007; Teruel, 2000, 2011; Teruel & García, 2008a –b; Teruel & Sánchez, 2009, 2010; Teruel & Kovařík, 2011).

The variation of pectinal tooth counts known for T. pictus is compiled in Table 6. Both Pocock (1893) and Lourenço (1984) recorded 20–21 in males and 18–21 in females; it should be mentioned here that Pocock (1893) gave only ranges for each sex, but Lourenço (1984) presented actual individual counts. Also, the two additional topotypes herein examined (male and female) have 20/20 pectinal teeth.

The variation of the number of principal rows of granules on pedipalp fingers known for T. pictus is compiled in Table 7. Pocock (1893) recorded 13 rows, but Lourenço (1984) recorded 15 rows for the movable finger of the same specimens without any comments on this discrepancy. In the two additional specimens herein studied, the fixed finger has 13/13 rows, and the movable finger has 14/15 rows in the adult male and 14/ 14 in the juvenile female.

Juveniles ( Fig. 3 View Figure 3 ) are very similar to adults, but can be distinguished by the somewhat different coloration (basically paler, with metasomal segments IV–V and telson of the same color as the rest of metasoma), a less sclerotized cuticle (especially in metasoma and pedipalps), the pedipalp chelae relatively smaller and narrower than patella, metasoma relatively more slender and parallel-sided, and a totally different subaculear tubercle (much stronger, sharp and with dorsal and ventral granules).

Ecological notes: according to the information kindly provided by one of the collectors (GA), the specimens herein examined were collected under barks of trees in forest, sympatric with Didymocentrus minor Francke 1976 (under rocks in the ground).

Material examined: SAINT VINCENT AND THE GRENADINES, Saint Vincent , Mt. St. Andrew, 19 October 2004, G. Alayón & M. da Silva leg., 1 adult ♂ topotype ( IES); Brighton Village, 22 October 2004, G. Alayón & M. da Silva leg., 1 juvenile ♀ topotype ( IES) .

Remarks: for a detailed comparison between this species and T. smithii , see General Remarks.

The status and composition of the name-bearing types of T. pictus is currently confused. Pocock (1893) did not designate a holotype, and based the original description on an undetermined number of specimens: measurements of one adult male and female were actually given, and in page 383 he mentioned “... the largest examples of T. pictus ...” [italics herein added], which clearly implies the existence of at least three specimens.

Lourenço (1984) examined two adult males and three adult females ( BMNH: 1894.10.14 .21–25), and in page 99 he stated that these specimens “... could not be warranted to be part of the original type-series of Pocock. At least one of these females corresponds very well to the female described by Pocock ...” [original text in French, translation and italics herein added], and in page 101 he first wrote that the specimen with 20/19 pectinal teeth “... could be the type female ...” [original text in French, translation and italics herein added], and then referred to the whole sample as the “ type-series? ” [original text in French, translation and italics herein added] .

Fet & Lowe (2000: 255) considered that Lourenço (1984) had designated the above-referred female as the lectotype, and the remaining four specimens as paralectotypes. Nevertheless , such lectotype designation is not valid according to the Article 74.5 of the International Code of Zoological Nomenclature ( CINZ, 2000: 85), because Lourenço (1984) never selected unambiguously this female as the lectotype (i.e., all three references to any “type” were clearly conditional by the use of the modal auxiliary verb “could” or a question sign). Nor is Fet & Lowe (2000) a case of inadvertent lectotype designation, because it does not fulfill the Article 74.7.3 of the Code ( CINZ, 2000: 86): it does not contain an explicit declaration of such a purpose .

Apart from this, Lourenço (1984: 101) contradictorily listed two females from Grenada (catalogued BMNH: 1894.10.20.7–16) as the types of both T. pictus (twice on text lines 8 th and 22 nd) and T. smithii (once on figure captions 21–27), obviously because he considered both taxa as synonyms. Again, this neither does represent a valid designation of a lectotype because: (1) according to the Article 72.9 of the Code (CINZ, 2000: 81), if two or more species-level nominal taxa become included into a single species-level nominal taxon, their name-bearing types remain unaltered, and for both T. pictus and T. smithii these are Pocock's original type-series; (2) the two above-mentioned females from Grenada are not original types of T. smithii either (see below, in the Remarks section of this species).

Because of all these reasons, it is clear that the name-bearing type of T. pictus is a series of syntypes, most likely the BMNH sample catalogued 1894.10.14.21–25. It is highly recommended here that any other author who eventually decides to designate a lectotype, must select the adult male measured and illustrated by Pocock (1893: 382–383; pl. XXX, fig. 8; the size match between the table and figure demonstrate that both refer to the same specimen about 63.5 mm long), following the Recommendation 74B of the Code that gives preference to a syntype which has been illustrated (CINZ, 2000: 86). It also concurs with the fact that all diagnostic characters of T. pictus are best expressed in this sex.