Mayazomus estor (Monjaraz-Ruedas & Francke, 2016)

Monjaraz-Ruedas, Rodrigo & Francke, Oscar F., 2016, Systematics of the genus Mayazomus (Arachnida: Schizomida): the relevance of using continuous characters and pedipalp setae patterns to schizomid phylogenetics, Zoological Journal of the Linnean Society 176 (4), pp. 781-805 : 797-801

MAYAZOMUS ESTOR (DE ARMAS & VÍQUEZ, 2010)

COMB. NOV. ( FIGS 8–10 )

Heteronochrus estor de Armas & Víquez, 2010: 12– 13 , fig. 4A–H, table II; Moreno-González & Villarreal, 2012: 74–77, tables 2–4.

Emended diagnosis

Males can be distinguished by the pedipalp trochanter having a long, pointed apical process less than 45°; the pedipalp femur with spiniform setiferous tubercles Fv1 and Fv2 small and close to each other; setae Fv1 located ventrally, setae Fe1 small and acuminate; the apophysis on the mesal surface (FAP) small and inconspicuous; pedipalp tibia without mesal apophysis (TMA); male flagellum cordate, with a submedian depression on the dorsal surface of the flagellum ( Fig. 9E– G ); pedipalp trochanter of heteromorphic male with a pronounced mesal spur. Females can be distinguished by the spermathecae ( Fig. 10D ) having lobes subequal in length; median lobes curved along their length; a wide chitinized arc. Mayazomus estor resembles M. yaax in the general shape of the pedipalp, having the femur less robust than the other species of the genus, and the females having a V-shaped chitinized arc; M. estor resembles M. infernalis in the shape and subequal length of the spermathecae lobes, and the curvature on the median lobes. The male flagellum of M. estor is cordate in shape, with a single dorsal submedian depression, whereas in M. infernalis the flagellum has two inconspicuous posterior depressions.

Supplementary description

The following description and meristic data for the holotype and paratypes supplement the original description by de Armas & Víquez (2010).

Chelicerae ( Fig. 10A–C ): Moveable finger: serrula with 16 teeth, guard tooth present. Fixed finger with four smaller teeth between two primary teeth. Setation: setal group formula: 1:3, 2:6, 3:4, 4:2, 5:7, 6:1. G1 (setae group 1) with three spatulate setae, covered with few spinose and small spicules starting from the middle of the shaft; G2 composed of six feathered setae subequal in length, and shorter than moveable finger length; G3 with four setae subequal in length, feathered apically, and smooth basally; G4 consisting of two setae, smooth, short, and thick, elongated at the tip; G5 with seven similarsized setae, feathered apically and longer than fixed finger; G6 with one smooth setae about half of moveable finger length.

Pedipalps ( Fig. 9A–D ): Robust 2.42 times longer than propeltidium length. Trochanter 2.33 times longer than high; apical process pointed and broadly triangular, less than 45°; mesal surface with a row of three setae near ventral margin, plus two setae near dorsal margin; with a pronounced medial mesal spur. Femur 1.52 times longer than high, distal margin straight, ventral margin flattened; distal margin on ectal surface with spiniform setiferous tubercles Fv1 and Fv2 small, close to each other; Fe1 small, an acuminate setae on ectal surface; mesal surface with a row of three ventral setae plus two dorsal spiniform setae (Fvr1–3, setae Fd1 and Fd2); distal margin of the mesal surface with a very small and inconspicuous apophysis (FAP). Patella slightly curved, inverse arc-shaped; setae Pe, Pm, Pe5–3, and Pm5–3 acuminate, without special armature. Setae formula on tibia 3:3:4 (external row: medial row: internal row); seta Tm1 acuminate and setae Tm2 feathered; without tibial mesal apophysis (TMA). Claw about half as long as dorsal length of tarsus; spurs asymmetrical, 0.09 mm long.

Legs: Leg I, basitarsal-telotarsal proportions: 20:3:3:4:4:4:9. Femur IV 2.25 times longer than wide.

Opisthosoma: Tergite I with two pairs of microsetae anteriorly plus one pair of macrosetae 2 + 1; tergite II with three pairs of microsetae anteriorly plus five macrosetae 3 + 2; tergites III–VII with one pair of dorsal setae each; tergites VIII–IX with one pair of dorsal and one pair of lateral setae each; segments X–XI telescoped with one pair of lateral setae and five ventral setae; segment XII with one dorsal and two lateral setae and three ventral pairs of setae, without posterodorsal process. Sternites with scattered setae; genital aperture without microsetae.

Flagellum ( Fig. 9E–G ): Dorsoventrally flattened, cordate in shape; 2.08 times longer than wide, 3.00 times longer than pedicel length; with a single dorsosubmedian depression. Setation: Dm1 situated over the bulb base; Dm4 situated medially; Dl1 at same level as Vl1; Dl3 posteriorly to Vl2; pair Vm2 present; seta Vm1 posteriorly to Vm2; Vm 5 posterior to Vl1. With one pair of antero-dorsal microsetae between Dm1 and Dl1, nearest to Dl1; one pair of antero-lateral microsetae on flagellar pedicel; and with two pairs of microsetae between Vl1 and Vl2.

Female (paratype): Similar to male, except in pedipalp development and without the projected spur on the trochanter, pedipalp 1.88 times longer than propeltidium length, pedipalps similar to the homeomorphic male ( Fig. 9B ); setation as on male. Flagellum with three annuli. Setation: seta Dl1 reduced and anterior to Vl1; Dl3 posterior to Vl2; Vm2 present and reduced; seta Vm1 at same level as Vm2. Segment III with one lateral pair of microsetae near to Vm4. Segment IV with one pair of distolateral microsetae close to Dl3. Spermathecae ( Fig. 10D ) with four lobes; median pair curved along its length, subequal in length; lateral pair curved outwardly, both with duct openings. Gonopod long, wide. Chitinized arch V-shaped, posterior branch wide basally, with irregular margins, lateral tip not sclerotized. Chelicera: serrula with 18 teeth. Setal group formula 1:3, 2:6, 3:4, 4:2, 5:7, 6:1. Setal group 3 with two setae small and two larger, both feathered. Fixed finger with five teeth.

Variation

The homeomorphic male differs from the heteromorphic male mainly in the pedipalp size (total length of the pedipalp in heteromorphic male 2.42, and in homeomorphic male 1.8 times the length of the propeltidium); trochanter of the pedipalp without the spur project- ed; femur with setae Fv1 and Fv2 less developed; the development of the femoral apophysis is very poor in both types of male. However, based on the morphometric ratios, the development of the femoral apophysis, and the curvature of the patella, the male described by de Armas & Víquez (2010) (and revised in this work) as a heteromorphic male is probably a pseudoheteromorphic male, as was reported for M. loobil by Monjaraz-Ruedas & Francke (2015).

Distribution

Known only from the type locality.

Natural history

The specimens were collected sympatric with Stenochrus portoricensis .

Figures

Figure 8. Mayazomus estor comb. nov. Paratype male. Habitus: A, dorsal view. Paratype female. Habitus: B, dorsal view. Scale bar = 1 mm.

Figure 9. Mayazomus estor comb. nov. Holotype homeomorphic male. A, pedipalp ectal view. Female. B, pedipalp ectal view. Paratype heteromorphic male. Pedipalp (C, D): C, ectal view. D, mesal view. Holotype male flagellum (E–G): E, dorsal view. F, ventral view. G, lateral view. Abbreviations: Fe, femur ectal; Fv, femur ventral; AP, apical process; Dm, dorsal median; Dl, dorsal lateral; Vm, ventral median; Vl, ventral lateral. Scale bars = 0.2 mm.

Figure 10. Mayazomus estor comb. nov. holotype male. Chelicera (A–C): A, mesal view. B, fixed finger. C, moveable finger. Paratype female. Spermathecae: D, dorsal view. Scale bars = 0.05 mm.