Cubacanthozomus rowlandi ( Dumitresco, 1973 )

Barroso, Aylín Alegre, 2017, Redescription of the monotypic genus Cubacanthozomus (Schizomida: Hubbardiidae) and conservation status of its type-species, Zootaxa 4323 (4), pp. 534-546 : 537-542

Cubacanthozomus rowlandi ( Dumitresco, 1973)

Figs. 1‒9 ; Table 1

Schizomus rowlandi Dumitresco, 1973: 279 ‒289, 291–292, figs. 1‒2, 3a–b, 4a–d, 5a, 6a–c, 7a. Dumitresco, 1977: 147 ‒151, 153‒155, 157‒158. Rowland & Reddell, 1977: 80, 88‒89. Rowland & Reddell, 1979: 163, 188. Decou, 1981: 11. Rowland & Reddell, 1981: 43, 45. Armas & Alayón García, 1984: 9‒10. Silva, 1988: 81. Armas, 1989: 9, 34. Decu, Georgescu & Viña Bayés, 1989: 223. Decu & Juberthie, 1994: 464.

Cubazomus rowlandi: Reddell & Cokendolpher, 1995: 5 , 12, 19, 68, 92. Pérez & Yager, 2001: 74. Harvey, 2003: 108.

" Cubazomus " rowlandi: Armas, 2002: 8 .

Troglocubazomus rowlandi: Teruel, 2003: 40 , 41, 43‒44, 64. Armas, 2004: 52 ‒53.

Cubacanthozomus rowlandi: Teruel, 2007: 48 , 49, 50. Armas & Teruel, 2009: 448, 449, 450. Teruel, 2012: 39, 40. Alegre & Barba, 2014: 45, 54. Armas et al., 2016: 151 ‒152.

Type data: Male holotype (ISER), reportedly collected in Cueva de las Columnas, Guanayara, Trinidad, Sancti Spíritus province (not examined). Really collected in Cueva de Majana, Baracoa. Therefore, we are herein emending the type locality as Cueva de Majana (= Cueva de los Murciélagos), Majana, Baracoa, Guantánamo province, Cuba. The holotype was dissected by Dumitresco and mounted in PVA (polyvinyl-alcohol) on at least six microscope-slides, but without cover-slips. Those six microscope-slides are in a small container with the following hand-writing notice: “ S. rowlandi ”; in the extremes of each microscope-slide there is a small hand-writing labels: on one, written “Cueva de las Columnas”; on the other: Schizomus rowlandi ♂”. In one of those microscopic preparations there are mixed parts of S. rowlandi male and S. negreai . In other preparations there are parts of female S. rowlandi from “C[ueva]. la Majana”, which obviously belong to paratype specimens. No other data or type identification is present in those microscopic preparations.

Distribution: Only known from two neighboring caves in Majana area, Baracoa municipality, Guantánamo province ( Fig. 9 ).

Material examined. CUBA: Guantánamo province: Baracoa municipality: Majana : Cueva de Máximo (20°20’41,6” N— 74°27’59,4” W; 45 m a.s.l.): 1 female, 1 male (IESC-3.3777), November 27, 2016, A. Alegre & R. Barba, dark zone, under stones ; 1 female (IESC-3.3766), March, 2, 2016, R. Barba & A. Alegre, dark zone, under stone.

Emended diagnosis. A medium-sized species (4.5–4.7 mm total length); pale brown in general aspect.

Propeltidium 1.3‒1.7 mm long, without eyespots. Abdominal segments X‒XII ventrally with five long apically trifid setae ( Figs. 15 , 16 ). Male: propeltidium with two pairs of dorsal setae; abdominal segment XI with setae dorso-lateral 1 (Dl1) modified; XII with setae Dl1 and Dl2 modified ( Figs. 1 , 16 ; Dumitresco, 1973: fig. 5 A). Female: propeltidium with three pairs of dorsal setae; genital plate (sternite II) with some apically trifid setae; spermathecae composed by two pairs of tubular lobes, each nearby basally ( Fig. 7 ); chitinized arch V-shaped, with anterior branch indistinct, lateral tip conic and internal angle rounded; gonopod absent.

Complementary description. The following description and data are based on a male and two females from Cueva de Máximo, approximately 350 m from the real type locality and supplements the original description given by Dumitresco (1973).

Homeomorphic male: Pale brownish; propeltidium, metapeltidium, chelicerae, pedipalps and flagellum slightly darker.

Prosoma: Propeltidium with two setae (1+1) on the anterior process and two pairs of dorsal setae; eye spots absent. Mesopeltidial plates 0.08 long, 0.25 wide; gap between the plates 0.25. Metapeltidium 0.30 long, 0.78 wide. Anterior sternum with 11 setae, plus two sternopophysial setae; posterior sternum with six setae.

Chelicerae: Movable finger with five small accessory teeth; serrula with 23 teeth. Fixed finger with four smaller teeth between two primary teeth. Setal group formula: 1:3, 2:3, 3:3, 4:2, 5:7, 6:1, 7: 4. G1 (setae group 1) with three spatulate setae, covered with small spicules starting from near the base of the shaft ( Fig. 10 ; Dumitresco, 1973: fig. 1 E); G2 composed of three feathered setae, subequal in length, and as long as the movable finger; G3 with three short setae, subequal in length, feathered apically and smooth basally; G4 consisting of two setae, smooth, short and spine-like; G5 with seven similar sized setae, feathered apically and shorter than fixed finger; G6 with one smooth seta 0.57 times as long as the movable finger.

Pedipalps ( Figs. 11–13 ): Short, 2.18 times longer than propeltidium length. Trochanter short, 2.50 times longer than high; apical process triangular about 45°; with 12 setae on ventral margin; mesal surface with a row of four setae near ventral margin; without a mesal spur. Femur 1.87 times longer than high; distal margin straight, ventral margin convex; distal margin on ectal surface with spiniform setae Fv2 and Fe2 small, close to each other; plus Fv1 and Fe1 small spiniform setae on ventral margin ( Fig. 11 ); mesal surface with three ventral setae (Fvr1, Fvr2, Fvr3), plus one small dorsal spiniform setae ( Fig. 12 ). Patella 3.20 times longer than high, with three ventral ectal spiniform setae (Pe2, Pe3, Pe5), being Pe2 the longest and four ventral mesal setae (Pm2, Pm3, Pm4, Pm5), long ( Fig. 13 ). Tibia with scattered long setae. Claw about 0.5 times as long as dorsal length of tarsus; spurs asymmetrical, 0.07 long.

Legs: Leg I, basitarsus 9.0 and 4.0 times longer than tarsomeres 1 and 4 of the metatarsus, respectively. Femur IV 3.40 times longer than high.

Opisthosoma ( Figs. 14–15 ): Tergite I with two pairs of microsetae anteriorly plus one pair of setae (2 + Dm); tergite II with three pair of microsetae anteriorly plus one pair of setae (3 + Dm); tergites III–VII with one pair of dorso-medial (Dm) setae each; tergite VIII with one pair of dorso-medial setae plus a pair of dorso-lateral (Dl2) setae; tergite IX with two pairs of dorso-lateral (Dl1, Dl2) setae. Segment X without dorsal setae, with five ventral long apically trifid setae. Segment XI with one pair of dorso-lateral (Dl2) modified setae and five ventral apically trifid setae, long. Segment XII without posterodorsal process, with three pairs of dorsal setae: Dm, Dl1, Dl2, being Dl1 and Dl2 greatly modified; with seven ventral setae: Vl2 pair is short, acuminate; Vl1, Vl2, and Vm are long, apically trifid ( Figs. 14‒16 ).

Flagellum ( Figs. 1–4 , 16 ): dorsoventrally depressed, cordate in shape, with a longitudinal dorso-medial depression; 1.36 times longer than wide, 2.62 times longer than pedicel length; pedicel laterally compressed. Chaetotaxy: Dm1 situated on the center of the pedicel; Dm4 situated subdistally; Dl1 shorter than Vl1 setae; Dl1 distal to Vl1; Dl3 basal to Vl2; pair Vm2 present; seta Vm1 distal to Vm2 pair; Vm5 distal to Vl2. With several lateral microsetae between Dl1 and Dl3.

Female: Similar to male, except in the following characters: pedipalp length 2.40 times longer than propeltidium length; legs shorter. Flagellum: with two annuli; chaetotaxy ( Fig. 5, 6 ): setae Dl1 and Dl4 are the shortest, seta Dm1 shorter than Dl2; ventral setae are the longest. Genitalia: Spermathecae ( Figs. 7 , 8 ) with two pairs of tubular lobes subequal in length, both with glandular microtubes; chitinized arch V-shaped, with anterior branch indistinct, lateral tip conic and internal angle rounded; gonopod absent. Chelicerae: serrula with 21 teeth.

Natural history. This is a troglobitic species ( Dumitresco, 1973; Decu & Juberthie, 1994; Pérez & Yager, 2001; Teruel, 2003, 2007). The male and the two female specimens examined by us were found under stones in the dark zone of the cave. The female collected during March was found sympatrically with Rowlandius baracoae ( Armas, 1989) . The male and the other female collected in November were captured in the same zone where the harvestman Jimeneziella decui Avram, 1970 ( Opiliones : Incertae sedis) inhabits. Other arthropods collected or observed in the same chambers that this schizomid were Loxosceles caribbaea Gertsch, 1958 ( Araneae : Sicariidae ), undetermined trap-door spiders ( Barychelidae ), Paraphrynus robustus (Franganillo, 1930) (Amblypygi) , Cubacophus velutinus (Bonfils, 1981) (Orthoptera) and ants ( Formicidae ). For additional data see Alegre & Barba (2014) and Armas et al. (2016).

Conservation status. Teruel (2011, 2012), based on the scarce data about this species proposed that it should be listed under the category DD (Deficient data); however, recent data permits a new assessment. The troglobite condition of the species makes it very sensitive to any alteration of the cave environment, which is a very fragile ecosystem. Besides this schizomid is only known from two caves (Cueva de Majana and Cueva de Máximo), which occupy a very small area (<5 km ²) within the protected area Yara-Majayara, Baracoa, Guantánamo province. Cueva de Majana has been suffering some perturbations, like bat guano extractions, while Cueva de Máximo is better conserved, but also with sporadic bat guano extraction. The species seems to occur only in very low abundance, at least in Cueva de Máximo. Despite the collecting efforts and the time spent conducting research on the biology of the opilion J. decui by the second and third authors during two field trips to this cave, only three schizomids were observed in Cueva de Máximo. Also, during the last 45 years several researchers, including the present authors, have explored Cueva de Majana and its adjacent epigean areas searching for this species, but no specimens have been collected ( Teruel, 2003; unpublished data of the authors). Therefore further studies on the ecology and biology of this schizomid are needed. Nevertheless, this short range endemic species has a high risk of extinction and deserves to be included in the Red List of the IUCN under the category of endangered species [EN B2a,b(iii,iv)].

Remarks. As stated by Armas &Teruel (2009), the female flagellum illustrated by Teruel (2007: fig. 10a) does not belong to this species [it corresponds to a specimen identified by Dumitresco (1973: fig. 7 B) as S. negreai , but it might belongs to the very common schizomid Stenochrus portoricensis Chamberlin, 1922 ].

In schizomids, as a rule, dorsal chaetotaxy of the propeltidium does not vary between the sexes; nevertheless, the two female specimens examined by us have three pairs (and the male has two pairs).

Figures

FIGURES 8. Cubacanthozomus rowlandi (female from Cueva de Máximo, Baracoa). 8, genital atrium (G. A.) and posterior branch of the chitinized arch (C. A.).

FIGURE 9. Geographical distribution of Cubacanthozomus and related genera.

FIGURE 10. Cubacanthozomus rowlandi (female from Cueva de Máximo, Baracoa). Chelicera showing group 1 setae (G 1); s = serrula.

FIGURE 16. Cubacanthozomus rowlandi (male from Cueva de Máximo, Baracoa). Last abdominal segments and flagellum, lateral aspect, showing modified setae on segments XI and XII.

FIGURES 1 ‒ 4. Cubacanthozomus rowlandi (male from Cueva de Máximo, Baracoa). 1, abdominal segments XI ‒ XII and flagellum, dorsolateral aspect. 2 ‒ 4, flagellum, in dorsal (2), ventral (3), and lateral (4) aspects. Scale: 1 = 0.22 mm; 2 ‒ 4 = 0.16 mm.

FIGURES 5 ‒ 7. Cubacanthozomus rowlandi (female from Cueva de Máximo, Baracoa). 5 ‒ 6, flagellum in dorsal (5), and lateral (6) aspects. 7, spermathecae.

FIGURES 14 ‒ 15. Cubacanthozomus rowlandi (male from Cueva de Máximo, Baracoa). Opisthosomal chaetotaxy: 14, sternites V ‒ VIII; 15, sternite IX + segments X – XII.

FIGURES 11 ‒ 13. Cubacanthozomus rowlandi (male from Cueva de Máximo, Baracoa). Pedipalp chaetotaxy: 11, trochanter and femur, ectal; 12, femur and patela, mesal; 13, patela and tibia, ventral.