Megalostrata pacifica, Bonaldo & Galán-Sanchez & García, 2024

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 : 505-507

Megalostrata pacifica spec. nov.

Figs 7–9

Type material. Holotype ♀: COSTA RICA: Heredia: Finca la Selva , 3 km SE Puerto Viejo de Sarapiguí, understory of primary wet forest [10°26’04.7”N 84°01’00.6”W, 100m a.s.l.], leg. C.E. Griswold, 5–10.IX.1981 ( CAS 9036847 ).

Etymology. The specific name is a Latin adjective meaning peaceful, highlighting the fact that Costa Rica does not currently have a standing army.

Diagnosis. Females of M. pacifica spec. nov. are similar to those of M. raptor and M. depicta by the elongated, tube-shaped secondary spermathecae but can be readily distinguished from those of both species by the secondary spermathecae oriented longitudinally ( Figs 8A, B , 9A–D ) (oriented obliquely in M. raptor and M. depicta , Figs 5A, B ; Bonaldo 2000: figs 308, 309). The M-shaped posterior plate excavation ( Figs 8C , 9E, F ) is also diagnostic.

Description. Male: Unknown. Female (holotype). Carapace yellowish-orange, with reddish-brown marginal stripes with triangular expansions at the level of intercoxal spaces, paramedian stripes reddish-brown, cephalic region with two faint additional reddish-brown stripes, fovea reddish-brown. Chelicerae and endites yellowish-orange, labium reddish-brown. Sternum yellowish, with round setal bases. Legs yellowish-orange, femora darker. Abdomen dorsum yellowish-white, with narrow dark continuous stripes in median area. Total length 9.727. Carapace 3.896 long, 3.040 wide. Clypeus height 0.120. Eye diameters: AME 0.272, ALE 0.194, PME 0.196, PLE 0.158. Interocular distances: AME-AME 0.228, AME-ALE 0.112, PME-PME 0.273, PME-PLE: 0.284 ALE-PLE 0.095. Chelicera 1.746 long, 0.854 wide, with two promarginal and three retromarginal teeth. Sternum 1.901 long, 2.025 wide. Leg measurements: I—3.773, 1.576, 4.190, 3.558, 1.688, 14.785; II—3.812, 1.553, 3.883, 2.880, 1.285, 13.413; III—3.604, 1.392, 3.207, 3.640, 1.504, 13.347; IV—3.800, 1.241, 3.774, 3.532, 1.541, 13.888. Leg spination: I—femur d1-1-2, p0-1-1; tibia p1-1, r1-1; metatarsus v1-1-1-1. II—femur d1-2-1; tibia p1-1, r1- 1; metatarsus v1-2-1-1-1. 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 5.826 long, 3.134 wide. Epigynum. Epigynal plate oval, anterior portion convex, posterior atrium undifferentiated, transversal anterior ridge absent; posterior margin of epigynal plate with median triangular projection; margin of posterior plate excavation Mshaped in posterior view; copulatory openings large, exposed on epigynal plate surface. Copulatory ducts short, straight, oriented longitudinally; secondary spermathecae elongated, tube-shaped, oriented longitudinally; primary spermathecae reniform, positioned at level of copulatory openings, diameter larger than atrium height; fertilization ducts directed posteriorly ( Figs 8 , 9 ).

Distribution. Only known from the type locality ( Fig. 25 ).

Figures

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 7. Megalostrata pacifica spec. nov., female holotype (CAS 9036847): A dorsal view; B ventral view; C lateral view. Scale bars: 1 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 9. Megalostrata pacifica spec. nov., female holotype, epigynum (CAS 9036847):A, C ventral view; B, D dorsal view; E, F posterior view (A, B, E undigested; C, D, F digested). Abbreviations: CO, copulatory opening; FD, fertilization ducts; S1, primary spermathecae; S2, secondary spermathecae; PeP, posterior epigynal plate; EPC, epigastric plate cuticle. Scale bars: 0.2 mm.

FIGURE 25. Known geographical distribution of Megalostrata species.