Siguanesiotes insulaepinorum (: Reddell & Cokendolpher, 1977) Teruel, 2018

Teruel, Rolando, 2018, Two new genera and a new species of schizomids (Arachnida: Schizomida) from Isla de Pinos, Cuba, Ecologica Montenegrina 19, pp. 33-49 : 37-40

Siguanesiotes insulaepinorum comb. n.

Figs. 1–2 , 6 . Table I

Schizomus insulaepinorum Armas, 1977: 1–5 , 8; figs. 1–2; tab. 1. Armas, 1984: 9. Armas, 1989: 1–2, 16–17, 30, 34, 36; figs. 3, 5d. Reddell & Cokendolpher, 1995: 6, 160–161. Harvey, 2003: 368.

Luisarmasius insulaepinorum: Reddell & Cokendolpher, 1995: 1 , 12, 19, 81–82, 140–141, 160; tabs. 2–3. Armas, 2004: 46. Harvey, 2003: 11, 368. Armas & Alayón, 2014: 47–48.

Type data. CUBA: ISLA DE LA JUVENTUD SPECIAL MUNICIPALITY: Isla de Pinos: Loma de Columbia ; 17/June/1974; L. F. de Armas; 1♂ heteromorphic holotype ( IES: 3.1679). Examined. Note: specimen in poor condition, see details and additional data below in Remarks section .

Additional material examined. CUBA: ISLA DE LA JUVENTUD SPECIAL MUNICIPALITY: Isla de Pinos: Northern tip of Sierra Chiquita (new record); 10/July/2018; T. M. Rodríguez; under rock at cliff base; 1♂ heteromorphic ( RTO) .

Diagnosis. As for the genus (see above).

Redescription (heteromorphic male holotype, unless otherwise noted). Coloration (fig. 2: male from Sierra Chiquita; see bleached holotype in fig. 1): immaculate light olivaceous, slightly darker on legs IV, abdomen and flagellum. Chelicerae and pedipalps with a subtle orange shade. Eyespots translucent, pale yellowish to whitish. Abdominal segment XII with posterodorsal area progressively darker distally, due to heavier sclerotization.

Pedipalp (fig. 1c, see male from Sierra Chiquita in fig. 2c): slightly elongate (1.57 times shorter than body, 1.54 times in male from Sierra Chiquita). Trochanter lanceolate (2.21 times longer than deep, 2.36 times in male from Sierra Chiquita), compressed, straight, and apically produced into a flat, triangular projection curved inwards; dorsal margin convex and bare; ventral margin convex, with 11–12 long, spiniform setae; inner surface with 3–4 spiniform setae arranged into a curved row, essentially parallel to ventral margin, internal spur medium-sized and located near the dorsal margin. Femur fusiform, stout (2.05 times longer than deep, 2.40 times in male from Sierra Chiquita), straight and not bent basally; dorsal margin widely convex, with 5–6 pairs of medium-sized spiniform setae; ventral margin widely convex, with two parallel rows of short, thick spiniform setae (one ventrointernal and two ventroexternals). Patella club-shaped, stout (3.08 times longer than deep, 2.73 times in male from Sierra Chiquita) and weakly bent basally; dorsal margin smooth, with 4–5 pairs of medium-sized, sedose setae; ventral margin with two rows of long, paired, rigid macrosetae (none especially modified), plus a similar, single macrosetae in subdistal position between the rows. Tibia subcylindrical, stout (3.40 times longer than deep, 2.89 times in male from Sierra Chiquita), vestigially bent basally; dorsal margin with 11–12 variously sized setae, most of them sedose; ventral margin with three essentially parallel rows of long, rigid setae all along: the ventrointernal row with four setae (some plumose or sinuose), the ventromedian row with 5-6 setae (some plumose or sinuose), and the ventroexternal row with four setae (unmodified). Tarsus conical, stout (1.20 times longer than deep, 2.50 times in male from Sierra Chiquita), straight and densely covered with variously sized, sedose setae; apical spurs almost symmetric (outer only slightly longer). Claw medium-sized, sharp, and shallowly curved.

Propeltidium (figs. 1a–b, see male from Sierra Chiquita in figs. 2a–b): with 1 + 1 apical and two pairs of dorsal setae. Eyespots large and subtriangular.

Mesopeltidia (figs. 1a–b, see male from Sierra Chiquita in figs. 2a–b): triangular, widely separated.

Metapeltidium (figs. 1a–b, see male from Sierra Chiquita in figs. 2a–b): completely divided into two well separated, obliquely paraboloid plates.

Legs (figs. 1a–b, see male from Sierra Chiquita in figs. 2a–b): I conspicuously attenuate, II–III slender. Leg IV femur elongate and robust, with anterodorsal margin angled at slightly less than 90°.

Abdomen (figs. 1a–b, d–e, see male from Sierra Chiquita in figs. 2a–b, d–e): not attenuate. Tergite I lacking anterior microsetae, II with 2–3 pairs. Tergites II–VII with setal formula standard: 2 / 2 / 2 / 2 / 2 / 2, setae large and rigid. Segment XII with dorsoposterior pair of macrosetae thick, dark and angled downwards; posterodorsal process absent.

Flagellum (figs. 1d–e, see male from Sierra Chiquita in figs. 2d–e): broadly subpentagonal, with pedicel/bulb angled at about 180°. Pedicel short and compressed (remarkably deeper than wide). Bulb in dorsal view very wide (1.07 times longer than wide in both available specimens), anterior margin very obtusely angled, lateral margins almost straight and slightly diverging backwards; bulb in lateral view moderately bulky (1.71 times longer than deep, 1.87 times in male from Sierra Chiquita), dorsally flat but apically raised, ventrally angled at about 95° (90° in male from Sierra Chiquita); dorsal surface with two longitudinal submedian furrows all along, which converge medially to resemble inverted parentheses; dm 1 seta located on pedicel/bulb joint, dm 4 in apical position; apex acute in dorsal view, conical and raised upwards in lateral view.

Distribution (fig. 6). As for the genus (see above).

Conservation status. Vulnerable (VU), meeting UICN criteria B1a+2a;D2: known from only three fragmented localities, comprising a pooled area smaller than 7 km 2.

Ecological notes. According to the detailed data kindly supplied by its collector (Tomás M. Rodríguez-Cabrera, pers. comm.), the specimen from Sierra Chiquita was found under a rock semi-buried in the leaf litter of a semideciduous forest, at the base of a limestone cliff. Here it lives syntopically with the new species described below, whose holotype was collected under an adjacent rock.

Apart from this, only scant information has been published. Armas (1977: 4) declared that the type series was collected under rocks and leaf litter, in low semicaducifolious forest at Cerro Columbia. Armas (1989: 16) recorded an additional capture on a cave wall, about 1.5 m over the floor of the semidarkness zone of Cueva del Lago, at Cerro de las Guanábanas.

Remarks. In the original description, the type series was declared to include six paratypes: two males, three females and a subadult of undisclosed sex ( Armas, 1977: 4). Later, Armas (1989: 16–17) mentioned an additional female from Cueva del Lago and last, Armas (2004: 46) stated that this species has been collected several times. Nevertheless, the only specimen present today at IES collection is (fortunately) the holotype.

However, the holotype is in poor condition due to deficient preservation and careless manipulation. It has decayed moderately by having been long stored in too diluted alcohol: the coloration is bleached, the exoskeleton has become translucent and detached from internal tissues, most setae of cephalothorax and flagellum are gone, and the metapeltidium and abdomen are distorted apparently by application of an excessive pressure with forceps (fig. 1).

The direct study of the holotype revealed that the original description based on this specimen has some serious errors, which will be corrected as follows. First, Armas (1977: 3) described the metapeltidium as "... with insinuation of median suture " (originally in Spanish, italics and English translation added here), but it is fully divided into two separate plates, as also seen in the additional male from Sierra Chiquita (fig. 2a). Second, the drawing of the flagellum in lateral view ( Armas, 1977: fig. 1c) wrongly depicts the pedicel/bulb angle at approximately 90° and the bulb much shorter and bulkier, whilst actually the angle is about 180° and the bulb is remarkably longer and flatter (compare to figs. 1e and 2e herein).

The pedipalps of Siguanesiotes insulaepinorum comb. n. pose an interesting problem. In none of the two currently available specimens, these appendages possess the degree of elongation usually regarded as heteromorphic, but neither as short as in a standard homomorphic. As there is anyway certain degree of elongation, they both are classified here as heteromorphics.

At least in Cuba, this kind of slightly elongate but robust pedipalps is typical of the large, pale Hubbardiinae genera such as Cokendolpherius , Cubacanthozomus , Guanazomus , Heterocubazomus , Reddellzomus , and Troglocubazomus . The lack of a close morphological resemblance amongst them seems to indicate that it does not represent a monophyletic group, but the surviving relicts of an old lineage that became largely replaced by more modern and ecologically successful taxa, such as Rowlandius and Stenochrus .

The holotype and the additional male from Sierra Chiquita show some minor differences, e.g., in pedipalp elongation and shape of flagellum (see figs 1–2), which could indicate the existence of more than one species across these isolated hills. However, it is more prudent to treat Siguanesiotes gen. n. as monotypic until larger samples become available and the variability within and between populations can be assessed.

Figures

Fig. 1. Adult male holotype of Siguanesiotes insulaepinorum comb. n. (see accompanying labels and poor condition of this specimen): a) habitus, dorsal; b) habitus, lateral; c) pedipalps, lateral; d) abdominal segments IX–XII and flagellum, dorsal; e) abdominal segments IX–XII and flagellum, lateral.

Fig. 2. Adult male of Siguanesiotes insulaepinorum comb. n., from Sierra Chiquita (see fresh, perfectly preserved specimen): a) habitus, dorsal; b) habitus, lateral; c) pedipalps, lateral; d) abdominal segments IX–XII and flagellum, dorsal; e) abdominal segments IX–XII and flagellum, lateral.

Fig. 6. Geographical distribution of Siguanesiotes gen. n. and Siguanesiotes insulaepinorum comb. n.: previous records (red symbols), new record (yellow symbol). Image frame = 500 x 220 km, inset = 20 x 13 km. Fig. 7. Geographical distribution of Pinero gen. n. and Pinero marmoreus sp. n. (yellow symbols, the southernmost is the type locality). Image frame = 500 x 220 km, inset = 20 x 13 km.