Sheylayongium, Teruel, 2018

Teruel, Rolando, 2018, The true generic identity of Mastigoproctus pelegrini Armas, 2000: a new genus of Antillean whipscorpions (Thelyphonida: Thelyphonidae), Ecologica Montenegrina 17, pp. 1-13 : 2-12

Sheylayongium gen. n.

Figs. 1–8 Mastigoproctus [in part: references to Mastigoproctus sp. , M. giganteus , M. liochirus and M. pelegrini ]: Franganillo, 1930a: 92. Franganillo, 1930b: 118. Franganillo, 1936: 144, 147. Moreno, 1939: 17–19; pl. 4, figs. 1–3. Armas, 1987: 1. Armas, 2000: 1–10; figs. 1–3. Harvey, 2003: 66–67, 366. Armas, 2004: 53. Domínguez & Armas, 2006: 22, 24; tab. 2. Teruel, 2010: 187, 193. Armas, 2013: 93. Armas & Alayón, 2014: 48–49; tab. 2. Teruel & Rodríguez-Cabrera, 2014: 115–117; figs. 1–3.

Type species. Mastigoproctus pelegrini Armas, 2000 [= Sheylayongium pelegrini ( Armas, 2000) comb. n.], by both present designation and monotypy.

Etymology. This new genus is named after Sheyla Yong (Havana, Cuba), the youngest and most-talented Caribbean entomologist, in recognition to her outstanding contributions to the taxonomy of Cuban orthopteroid insects and also, in appreciation of all her continuous and selfless support to my professional and private life. The generic epithet is neuter in gender.

Diagnosis. Size small for the family (25–35 mm). Chelicera-pedipalp stridulatory organ absent (fig. 5d). Cheliceral movable finger with outer basal notch rudimentary. Pedipalps (figs. 1–2) short and robust, entirely smooth and glossy, with sexual secondary dimorphism vestigial; trochanter with six anterodorsal spines (S1– S5 + AS); femur with dorsal internal and ventral internal teeth reduced. Carapace (fig. 3a) with anterolateral carinae well developed, granulose, on basal two-thirds of the distance between median and lateral ocular groups; interocular triangle (i.e., area delimited by the three ocular tubercles) largely smooth and glossy; each lateral ocular group formed by three large pale ocelli encircling two rudimentary dark ocelli. Tibia with ventrodistal spur only on leg IV. Sternum (fig. 4a) with a deep, wide longitudinal furrow all along median line. Abdominal tergites (fig. 3b) entire, only subdivided by a pale suture on II–III and anterior part of IV; segment X with pleuron rudimentary; segment XII with a pair of oval to vertically lanceolate ommatoids. Abdominal sternites (fig. 4b) undivided, II unmodified (only slightly bulky in adult male), III and V highly modified (see below for each sex). Flagellum (fig. 1) medium-sized, with 30–38 flagellomeres and with whip organs well developed, in ventrobasal location. Male: pedipalp trochanter with spines blunt, AS weak to vestigial; femur with dorsal internal tooth vestigial, ventral internal tooth small; patella and tibia with dorsal apophysis almost smooth on both edges. Sternite III with median area raised, triangular, whitish, densely setose and fenestrate; V with a large, oval to round, very densely setose (tufted) median depression. Genitalia (fig. 5a): standard for Mastigoproctinae . Female: pedipalp trochanter with spines sharp, AS strong; femur with dorsal internal tooth small, ventral internal tooth moderate; patella and tibia with dorsal apophysis serrate on both edges. Sternite III with median area slightly raised, triangular, translucent and sparsely setose; V medially with a small, oval to drop-shaped, sparsely setose (not tufted) median depression. Genitalia (figs. 5b–c): single pair of seminal receptacles, each shaped as a baby's bottle and with two very different parts: a basal half membranose, translucent, tubular and very short, plus a distal half highly sclerotized, very dark and nipple-shaped, with single apical bulb kidney-shaped, much narrower than base, about as wide as neck and curved backwards to outwards.

Comparisons. Sheylayongium gen. n. must be compared first to Mastigoproctus because this is the genus where its single species was placed. These two genera can be easily distinguished by the following unambiguous characters:

1. Adult size: small in Sheylayongium gen. n. (28–35 mm), vs. medium to large in Mastigoproctus (43–75 mm).

2. Stridulatory organ: entirely absent in Sheylayongium gen. n. (no plectrum or pars stridens, only a few sedose setae scattered on facing surfaces of chelicera manus and pedipalp coxa), vs. present in Mastigoproctus (facing surfaces of chelicera manus and pedipalp coxa with plectrum [rigid macrosetae] and pars stridens [rigid macrosetae plus cristulae], respectively).

3. Pedipalp sculpture: entirely smooth and glossy, only with inconspicuous punctations at base of some setae in Sheylayongium gen. n., vs. tuberculate, granulose, cristulate and/or coarsely punctate in Mastigoproctus .

4. Carapace sculpture: interocular triangle largely smooth and glossy in Sheylayongium gen. n., vs. densely granulose, tuberculate and/or rugose in Mastigoproctus .

5. Sternum ornamentation: with a conspicuous median longitudinal furrow in Sheylayongium gen. n., vs. evenly convex to tectiform, but always lacking such furrow in Mastigoproctus .

6. Sternite V ornamentation: with a densely setose median depression in Sheylayongium gen. n. (much larger and tufted in males), vs. unmodified in Mastigoproctus .

7. Female spermathecae: distal "nipple" of each lobe with apical bulb kidney-shaped, about as wide as neck and much narrower than base in Sheylayongium gen. n., vs. spherical to oval, wider than neck and as wide as base or wider in Mastigoproctus .

The diagnostic differences of the other five American genera of Thelyphonida against Sheylayongium gen. n., are detailed in alphabetical order as follows:

1. Mayacentrum Víquez & Armas, 2006 . 1) Adult size smaller: 15–23 mm. 2) Male pedipalp trochanter with spines S4 and S5 basally fused into a bicusp. 3) Carapace with anterolateral carinae extending only along basal half of the distance between median and lateral ocular groups. 4) Distal "nipple" of each spermathecal lobe with apical bulb spherical to oval, wider than neck and as wide as base or wider. 5) Sternite V unmodified. 6) Female with most abdominal tergites divided. 7) Flagellum shorter, with 20– 28 flagellomeres and lacking whip organs. See Víquez & Armas (2006). This genus is endemic from Central America (southeastern Mexico through northern Nicaragua).

2. Mimoscorpius Pocock, 1894 . 1) Adult size larger: 35–46 mm. 2) Pedipalp coxa ventrally with a very strong transversal groove. 3) Male pedipalp completely different in armature and shape: inner surface very densely setose, patella with apophysis very long, tibia globose. 4) Sternite II posterolaterally inflate and with posterior margin medially bilobed. 5) Sternite V unmodified. See Armas & Víquez (2005) and Huff et al. (2008). This genus is endemic from Central America (southern Guatemala).

3. Ravilops Víquez & Armas, 2005 . 1) Adult size smaller: 15–22 mm. 2) Carapace lacking anterolateral carinae. 3) Each spermathecal lobe with two spherical apical bulbs, the dorsal one much larger than the ventral one. 4) Sternite V unmodified. 5) Flagellum shorter, with 20–28 flagellomeres and lacking whip organs. See Víquez & Armas (2005) and Teruel (2017). This genus is endemic from the Greater Antillean island of Hispaniola (west-central Dominican Republic).

4. Thelyphonellus Pocock, 1894 . 1) Adult size smaller: 20–28 mm. 2) Carapace lacking anterolateral carinae. 3) Each spermathecal lobe fusiform, entirely heavily sclerotized and lacking apical bulbs. 4) Sternite V unmodified. 5) Abdominal segment XII lacking ommatoids. 6) Flagellum lacking whip organs. See Haupt (2009) and Barrales-Alcalá et al. (2018). This genus is endemic from northern South America (western Colombia through northern Brazil).

5. Valeriophonus Víquez & Armas, 2005 . 1) Adult size larger: 35–45 mm. 2) Chelicera-pedipalp stridulatory organ well developed. 3) Male pedipalp completely different in sculpture, armature and shape: densely tuberculate, granulose and coarsely punctate, trochanter with spines very sharp, patella with apophysis very long, tibia globose. 4) Sternite V unmodified. 5) Flagellum lacking whip organs. See Víquez & Armas (2005). This genus is endemic from Central America (southern Costa Rica).

Distribution (fig. 8). Endemic to western Cuba, with its single species Sheylayongium pelegrini comb. n. widespread across Pinar del Río, Artemisa and Isla de Pinos. The single record from Mayabeque given by Armas (in Teruel & Rodríguez-Cabrera, 2014: 115), requires confirmation (see below, in Remarks section).

Types examined of Sheylayongium pelegrini comb. n. PINAR DEL RÍO: Minas de Matahambre: Pica-Pica: entrance to Cueva de Pío Domingo ; March /1961; G. Albañir; 2♂♂, 2♀♀ paratypes ( IES: 3.1893 – 3.1896) . ISLA DE LA JUVENTUD: Isla de Pinos: Sierra de Casas ; 26/April/1974; no collector; 1♂ paratype ( IES: 3.1859) . Loma de Columbia ; 17/June/1974; L. F. de Armas; 1♂ paratype ( IES: 3.1858) . Siguanea: near El Colony; September /1976; C. Fundora; 3 juvenile paratypes ( IES: 3.1860 –3.1862) .

New records for Sheylayongium pelegrini comb. n. (fig. 8). PINAR DEL RÍO: Sandino: Península de Guanahacabibes: Punta de Mangle, Playa El Perjuicio [= Playa Sierra], Farallón de los Ingleses, El Veral, La Bajada, Cueva de las Perlas, Playa La Botella, María La Gorda, Punta Caimán and Playa El Caimán. Guane: Sierra de Guane: Base de Campismo "Los Portales". Sierra de Paso Real: 1.5 km northwest of Molina. Minas de Matahambre: Sierra de Mesa: Loma de Mal Paso [= Loma de Paso Estrecho]. Sierra de San Carlos: northern slope along trail from Cueva de las Anas to Cueva de las Canteras. Sierra del Sumidero: southern slope along road from Sumidero to San Carlos. Viñales: Sierra del Infierno: Sendero "Las Maravillas" and Sitio del Infierno. Sierra de Viñales: Mogote La Penitencia. Mogote del Valle: Base de Campismo "Dos Hermanas", Ensenada del Itabo and surroundings of Cueva de la Vaca. Sierra de San Vicente: southwestern slope along road from San Vicente to Ancón. Sierra La Guasasa: Cueva del Cable, Hoyo del Plátano and southern slope along road from Viñales to Laguna de Piedra. Los Palacios: San Diego de los Baños: Las Yeguas. ARTEMISA: San Cristóbal: Cañón del río Santa Cruz.

Previous records for Sheylayongium pelegrini comb. n. (fig. 8). PINAR DEL RÍO: Sandino: Cueva la Barca ( Armas et al., 1989). Guane: Los Portales: Cueva Oscura ( Armas, 2000). Minas de Matahambre: Pica-Pica ( Armas, 1987); Sumidero: Cueva de Pío Domingo ( Armas, 2000); Sistema Cavernario Majaguas-Cantera: Cueva XX Aniversario ( Armas, 2000). Viñales: Sierra de Quemados: Hoyo de Fanía ( Armas, 2000), El Moncada ( Armas, 2000), Valle de Dos Hermanas ( Armas, 2000), Valle de Viñales ( Franganillo, 1930a) and Cueva del Indio ( Armas, 2000). La Palma: Mil Cumbres ( Armas, 2000). ARTEMISA: San Cristóbal: Rancho Mundito ( Armas, 2000). ISLA DE LA JUVENTUD: Isla de Pinos (all by Armas, 2000): Sierra de Caballos; Sierra de Casas; Loma de Columbia; Siguanea: near El Colony. Note: part of these records contained erroneous data that were corrected in the list above; see a thorough discussion in Remarks section below.

Ecological Notes. According to the personal observations of the present author, label data of the examined specimens and published literature, Sheylayongium pelegrini comb. n. typically occurs in limestone areas of karstic relief, covered by well-preserved semicaducifolious and evergreen forests (fig. 7). This kind of landscape is abundant in cave formations, where this species frequently occurs as a typical troglophile. It ranges from the coast through low mountains under 500 m above sea level (fig. 8).

It digs shallow scrapes and short burrows under rocks, logs and other surface debris (figs. 6d–f), sometimes also inside fallen rotten logs and inside holes and cracks of rocky substratum and boulders, especially if filled at least partially with humus and leaf litter. Early-instar juveniles are common also inside leaf litter, mainly accumulated at base of trees, boulders and cliffs. Late-pregnant females and next-to-molt juveniles always lock up themselves to undergo the entire process in the bottom of the burrow, inside a totally sealed oval chamber (fig. 6f).

Females carrying litter (figs. 6d–f) were found by the author in April and May, just at the transition period from dry to rainy season. All of them that were stored alive became stressed and ate all their newborn, within the first hour after being captured. As expected, remarkably higher numbers of second-instar juveniles (= recruitment), were found in June and July.

In western Isla de Pinos, this species digs deeper burrows in siliceous sandy soils, vegetated with mixed savannah/pine forest ( Armas, 2000).

Under natural conditions, it preys upon smaller arthropods, especially millipedes (figs. 6c–f). Cannibalism seems frequent in at least one cave population ( Teruel & Rodríguez-Cabrera, 2014). See additional information in Armas (1987, 2000).

Remarks. Amongst the six other whipscorpion genera currently recognized to occur in the Western Hemisphere, Sheylayongium gen. n. is clearly related on morphological grounds most closely to Mayacentrum and Ravilops , especially the latter. It is only distantly related to Mastigoproctus , to which essentially the single linking character is the presence of well-defined carapacial anterolateral carinae.

Three of the characters diagnostic for Sheylayongium gen. n. are remarkable: the longitudinal furrow all along the sternum, the setose median depression on sternite V and the structure of female genitalia. These most likely represent autapomorphies, because all are unique to this genus inside the whole Mastigoproctinae . It is noteworthy to mention here that a similar setose median depression on male sternite V is diagnostic for Ginosigma Speijer, 1933 , but this South-East Asian genus is a typical member of the separate subfamily Thelyphoninae Lucas, 1835 , which implies a clear convergence instead of synapomorphy. Also, a sternal longitudinal furrow was described by Huff & Prendini (2009) in the single African whipscorpion Etienneus africanus (also a member of this subfamily), but the figure 5b of that paper depicts it very different in shape and thus, it is apparently not homologous to the one present in Sheylayongium gen. n.

The drawings of the cheliceral movable finger published by Armas (2000: figs. 1d–e) are absolutely wrong in all essential details, i.e., shape, curvature, thickness and sharpness of the finger, but especially the depicted absence of the outer basal notch and inner setation. For the present paper, both cheliceral movable fingers were carefully studied in more than 50 specimens from across the entire distributional range of Sheylayongium pelegrini comb. n., and this structure proved invariably and significantly different, as photographically shown herein (fig. 5d).

On the other hand, two locality records published by Armas (2000, 2013) have toponymical errors that are corrected accordingly:

1. "Cueva Oscura, Los Portales, San Diego de los Baños" ( Armas, 2000: 4; Armas, 2013: 93). It is actually located in southern Guane Municipality, more than 80 km northeast of San Diego de los Baños Municipality. This cave has been well known to speleologists and general collectors for more than 50 years.

2. "Hoyo de Fanías, Minas de Matahambre" ( Armas, 2000: 4–5; Armas, 2013: 93). The correct toponym is Hoyo de Fanía and is actually located in western Viñales Municipality. It is a collapsed pit in Santo Tomás Cave System and has been well known to speleologists and general collectors for more than 50 years.

Moreover, Armas (in Teruel & Rodríguez-Cabrera, 2014: 115) tentatively recorded this species from an undisclosed locality in Mayabeque Province (later, Luis F. de Armas himself personally communicated to the present author that it is Somorrostro, in San José de las Lajas Municipality). Such site is well outside the confirmed distribution of Sheylayongium gen. n. and thus, must be confirmed before accepted. Nevertheless, the voucher specimen is unfortunately missing from the IES collection: it was not found there by the present author during repeated, thorough revisions of its entire whipscorpion collection.

All new records listed above for Sheylayongium pelegrini comb. n. are supported by specimens collected mostly by the author and deposited in RTO collection. Complete data will be given elsewhere, in a forthcoming taxonomic revision of the genus (R. Teruel, in preparation).

Figures

Fig. 1. Adults of Sheylayongium pelegrini comb. n. from Minas de Matahambre, Pinar del Río; male from Sierra del Sumidero (left) and female from Sierra de Mesa (right), full-body views: a) dorsal; b) ventral.

Fig. 2. Adults of Sheylayongium pelegrini comb. n. from Minas de Matahambre, Pinar del Río; male from Sierra del Sumidero (left) and female from Sierra de Mesa (right), close-up of left pedipalp: a) dorsal; b) ventral.

Fig. 3. Adults of Sheylayongium pelegrini comb. n. from Minas de Matahambre, Pinar del Río; male from Sierra del Sumidero (left) and female from Sierra de Mesa (right), dorsal close-ups: a) carapace; b) abdomen.

Fig. 4. Adults of Sheylayongium pelegrini comb. n. from Minas de Matahambre, Pinar del Río; male from Sierra del Sumidero (left) and female from Sierra de Mesa (right), ventral close-ups: a) prosoma and sternite I; b) sternites II–V.

Fig. 5. Adults of Sheylayongium pelegrini comb. n., close-ups: a) genitalia in dorsal view, male from Sierra de Casas, Isla de Pinos, Isla de la Juventud; b–c) genitalia in dorsal view, female from Sierra de San Vicente, Viñales, Pinar del Río (abbreviations: ab = apical bulb, ne = neck, ba = base); d) facing surfaces of right chelicera (left = ventral view, center = outer view) and pedipalp coxa (right = inner view), female from entrance to Cueva de Pío Domingo, Minas de Matahambre, Pinar del Río.

Fig. 6. Live adults of Sheylayongium pelegrini comb. n., photographed in their natural habitat: a–b) male (a) and female (b) from Base de Campismo "Dos Hermanas", Viñales, Pinar del Río (see male largely covered with mud and with two foretic mites on tergite IV, as usual for this burrowing species during rainy season); c) male eating a millipede at Cañón del río Santa Cruz, San Cristóbal, Artemisa (photo courtesy Tomás M. Rodríguez-Cabrera); d) female with first-instar litter at Sierra La Guasasa, Viñales, Pinar del Río; e–f) female with first-instar litter at Sierra de San Carlos, Minas de Matahambre, Pinar del Río, outside (e) and inside (f) its burrow constructed under a large rock, see also food remains (wasp wings, beetle elytra, snail shells and millipede segments) cast aside burrow.

Fig. 7. Typical habitat of Sheylayongium pelegrini comb. n., e.g., semicaducifolious forest on karstic limestone relief at Viñales, Pinar del Río: a) surroundings of Cueva de la Vaca; b) Sendero "Las Maravillas".

Fig. 8. Confirmed geographical distribution of the genus Sheylayongium gen. n. and its single species Sheylayongium pelegrini comb. n.: previous records (red symbols) and new records (yellow symbols). Image frame = 300 x 220 km.