Megalostrata depicta (O. Pickard-Cambridge, 1895 )

Bonaldo, Alexandre B., Galán-Sanchez, M. Antonio & García, Fabián, 2024, Advances on the taxonomy of Megalostrata Karsch, 1880 (Araneae, Corinnidae, Corinninae), with descriptions of two new species, Zootaxa 5458 (4), pp. 495-523 : 501-504

Megalostrata depicta (O. Pickard-Cambridge, 1895)

Figs 1B , 3C, D , 4 , 5 , 6

Delozeugma depictum O. Pickard-Cambridge, 1895: 145 , pl. 19, fig. 1 (♂ from Teapa , Tabasco, Mexico, deposited in The Natural History Museum, London 1901.3.3.164, not re-examined).

Megalostrata depicta ; Simon 1897: 192, fig. 200, 203; Bonaldo 2000: 119, fig. 310–311.

Diagnosis. Males of M. depicta resemble those of M. raptor by the rounded, smooth apical tegular process, differing by the embolus retro-apically oriented (oriented retro-basally in M. raptor, Bonaldo 2000 , fig. 304) and by having a bifid RTA (entire in M. raptor, Bonaldo 2000 , fig. 305). They share with M. paludosa spec. nov. a retro-apically oriented embolus but can be distinguished by the smooth apical tegular process (with a field of apical teeth in M. paludosa , Fig. 22A ) and by the bifid RTA (entire in M. paludosa , Fig. 22A ) ( Figs 3C, D ; Bonaldo 2000, figs 310–311). Females are similar to those of both M. raptor and M. pacifica spec. nov. by the elongated, tube-shaped secondary spermathecae, but can be distinguished from the former by the oblique orientation of the secondary spermathecae (oriented longitudinally in M. pacifica spec. nov., Figs 8A, B ) and from the latter by the posterior atrium ill-defined, without a transversal anterior ridge at the level of the copulatory openings ( Figs 5A, B , 6A–D ) (posterior atrium defined by a transversal anterior ridge at the level of the copulatory openings in M. raptor , see Bonaldo 2000: fig. 308).

Description. Male. See Bonaldo (2000: 119). Additional documentation: Figs 1B , 3C, D , 4A, C . Female (UNAM) Carapace yellowish-orange, with marginal reddish-brown stripes and two wide paramedian reddish-brown stripes; cephalic region with two additional similarly colored bands, aligned with PME, fovea dark brown. Chelicerae, labium, and endites reddish-brown. Sternum yellowish-white, shield-shaped, with round setae bases. Legs yellowish-orange. Abdomen dorsum yellowish-white, with wide dark continuous stripes on each side, merging posteriorly; medially with three pairs of black spots. Total length 9.400. Carapace 4.338 long, 3.407 wide. Clypeus height 0.201. Eye diameters: AME 0.300, ALE 0.251, PME 0.213, PLE 0.194. Interocular distances: AME-AME 0.260, AME-ALE 0.198, PME-PME 0.259, PME-PLE: 0.284 ALE-PLE 0.068. Chelicerae 1.833 long, 1.100 wide, with three promarginal and two retromarginal teeth. Sternum 2.139 long, 1.973 wide. Leg measurements: I—4.474, 1.100, 3.975, 4.625, 1.256, 15.430; II—3.936, 1.333, 3.758, 3.313, 1.550, 13.890; III—3.920, 1.352, 3.277, 2.638, 1.240, 13.427; IV—4.609, 1.290, 4.122, 4.620, 1.307, 15.948. Leg spination: I—femur d1-2-2, p0-1-0; tibia p1-1, r1-1; metatarsus v1-1-1-1-1. II—femur d1-2-2; tibia p1-1, r1-1; metatarsus v1-1-1-1-1. III—femur d1-1-1, p0-1-1; tibia p1-1; metatarsus d2-2-2, v1-1-1, p1-1-1, r1-1-1. IV—femur v0, d2-1-1-1, r1-1; tibia p1-1, r1-1; metatarsus d2-2-0, r1-1 Leg spination: I—missing. II—femur d1-2-2; tibia p1-1, r1-1; metatarsus v1-1-1-1-1. III—femur d1- 1-1, p0-1-1; tibia p1-1; metatarsus d2-2-2, v1-1-1, p1-1-1, r1-1-1. IV—femur v0, d2-2-1-1, r1-1; tibia p1-1, r1- 1; metatarsus d2-2-1, r1-1. Abdomen 5.012 long, 1.946 wide. Epigynum. Epigynal plate oval, anterior portion with shallow median depression; posterior atrium borders ill-defined, transversal anterior ridge absent; posterior margin of epigynal plate without median invagination; margin of posterior plate excavation slightly procurved in posterior view; copulatory openings large, exposed on epigynal plate surface. Copulatory ducts short, straight, oriented transversally; secondary spermathecae elongated, tube-shaped, oriented obliquely; primary spermathecae globular, positioned posteriorly to copulatory openings, diameter approximately equal to atrium height; fertilization ducts directed posteriorly ( Figs 5 , 6 ).

Variation. (5 ♀) total 9.530 –11.270. Carapace 4.030 –4.450 long, 3.430 –3.650 wide. Leg I—4.110–4.410, 1.500–1.800, 4.300–4.350, 2.750–3.200, 1.270–1.564.

Additional material examined. MEXICO: Veracruz, San Andrés Tuxtla, Estacion Los Tuxtlas [18°34’55.2”N 95°04’30.0”W], leg. F. Alvarez-Padilla et al., 20–27.IX.2017, 3 ♂, 7 ♀ ( UNAM) ; Same locality (18°21’04.0”N 95°02’35.0”W), leg. A.M. Girotti et al., 18–31.VII.2014, 1 ♀ ( IBSP 226286 ); Same locality (18°35’13.8’’N, 95°04’31.8’’W), leg. L.S. Carvalho, 18–31.VII.2014, 1 ♂ ( CHNUFPI 1485 ) .

Distribution. Southeast Mexico ( Fig. 25 ).

Figures

FIGURE 1. Living specimens of Megalostrata Karsch, 1880. A Megalostrata raptor (L. Koch, 1866), male (not collected) from Reserva Natural Miraflor, Nicaragua, photo by A. Anker; B Megalostrata depicta (O. Pickard-Cambridge, 1895), male (CHNUFPI 1485) from Estación de Biología Tropical “Los Tuxtlas”, Veracruz, Mexico, photo by L. S. Carvalho.

FIGURE 3. A, B Megalostrata raptor (L. Koch, 1866), male (UNAM INVPICV071):A palp, ventral view. B palp, retrolateral view; C, D Megalostrata depicta (O. Pickard-Cambridge, 1895), male (UNAM CORINN0039): C palp, ventral view. D palp, retrolateral view. Abbreviations: E, embolus; RTA, retrolateral tibial apophysis; TP, tegular process. Scale bar: 2 mm.

FIGURE 4. Megalostrata depicta (O. Pickard-Cambridge, 1895) (UNAM CORINN0039): A male, dorsal view; B female, dorsal view; C male, lateral view. Scale bar: 2 mm.

FIGURE 5. Megalostrata depicta (O. Pickard-Cambridge, 1895), female epigynum: A ventral view; B dorsal view; C posterior view. Scale bar: 0.2 mm.

FIGURE 6. Megalostrata depicta (O. Pickard-Cambridge, 1895), female epigynum: A, C ventral view; B, D dorsal view; E, F posterior view (A, B, E undigested; C, D, F digested; A, B, E, F IBSP 226286; C, D UNAM INVPICV071).Abbreviations. CO, copulatory opening; CD, copulatory duct; FD, fertilization ducts; S1, primary spermathecae; S2, secondary spermathecae; EPC, epigastric plate cuticle. Scale bars: 0.2 mm.

FIGURE 8. Megalostrata pacifica spec. nov.: female holotype (CAS 9036847): A epigynum, ventral view; B same, dorsal view; C same, posterior view. Scale bars: 0.2 mm.

FIGURE 22. Megalostrata paludosa spec. nov.. A, B male holotype:A palp, ventral view; B palp, retrolateral view. C–E female paratype (MUSEUV 2796): C epigynum, ventral view; D same, posterior view; E same, dorsal view. Scale bars. 0.2 mm.

FIGURE 25. Known geographical distribution of Megalostrata species.