Acantheis andreimishenini, Fomichev & Omelko & Marusik, 2023

Fomichev, Alexander A., Omelko, Mikhail M. & Marusik, Yuri M., 2023, A survey of the Sumatran Ctenidae (Araneae). 1. Two new Acantheis species, Zootaxa 5353 (2), pp. 117-130 : 123-124

Acantheis andreimishenini sp. n.

Figs 3–6 , 10–11 , 17–21 , 26–29 , 31–35 , 46–48

Types. INDONESIA: Sumatra Island: Aceh Prov.: holotype ♁ ( ISEA, 001.9532), Kedah Vil. [03°59′N, 97°15′E], 1300–1500 m, 1988 (precise date unknown), unknown collector . Paratypes: 3♁ ( ISEA, 001.9533), 1♀ ( ISEA, 001.9534), together with the holotype .

Etymology. The species name is a patronym given in honor of the teacher and friend of Alexander A. Fomichev, Andrei I. Mishenin (Novosibirsk, Russia), brother of Sergei I. Mishenin, on the occasion of his 60th anniversary.

Diagnosis. This new species is similar to A. laetus from Kalimantan and to A. sergeimishenini sp. n. and A. dimidiatus from Sumatra in having a slender embolus (Em), a medially located tegular apophysis (TA) and an elongated cymbial tip. The male can be easily distinguished from that of A. laetus by the strongly curved embolus (vs. smoothly rounded, cf. Fig. 27 and Lehtinen 1967: fig. 410), and from that of A. sergeimishenini sp. n. by the smaller body size (carapace length 5.8 vs. 7.7), the shorter bulb (1.03 mm vs. 1.32 mm), the non-bifurcated retrolateral tibial apophysis (RTA) (vs. bifurcated, cf. Figs 20 and 15 ), the round tegular apophysis (seen in ventral view; vs. comma-shaped, cf. Figs 27 and 23 ) and the ventral (VB) and dorsal (DB) branches of the embolus with the same width (vs. the ventral branch twice as wide as the dorsal one, cf. Figs 31 and 30 ). The male of A. andreimishenini sp. n. differs from that of A. dimidiatus by the wide cardiac mark reaching middle part of opisthosoma (vs. thin stripe reaching spinnerets, cf. Figs 3 and 36 ), the median band on the carapace as wide as the distance between PLE (vs. as wide as distance between PME), the circular tegular apophysis (vs. triangular, cf. Figs 27 and 43 ), and the dorsal and ventral embolic branches equal in size (vs. ventral embolic branch twice thinner than dorsal one, cf. Figs 31 and 41 ). For a complete list of the differences between the males of A. andreimishenini sp. n., A. sergeimishenini sp. n. and A. dimidiatus , see Table 7 . The female of A. andreimishenini sp. n. is similar to that of A. indicus Gravely, 1931 from India, in having the rectangular septal base (SB), but differs in having parallel epigynal teeth (ET) (vs. converging), the posterior part of septal base with rounded angles (vs. sharp), and a wide gap between epigynal teeth and septal base (vs. narrow, cf. Figs 32–33 and Gravely 1931: fig. 3D).

Description. Male (holotype). Total length 11.5, carapace 5.8 long, 5.2 wide. Opisthosoma 6.1 long, 3.5 wide. Eye sizes and interdistances: AME 0.39, ALE 0.2, PME 0.46, PLE 0.43, AME–AME 0.17, AME–ALE 0.26, PME– PME 0.21, PME–PLE 0.29, AME–PME 0.14, ALE–PLE 0.23. Clypeus height at AME 0.49, at ALE 0.93. Labium as long as wide. For palp and legs measurements see Table 3 . For palp and leg spination see Table 4. Coloration ( Figs 3–4 , 10 ), carapace brown, with yellow median band. Clypeus and chelicerae dark brown. Labium and endites brown. Sternum and coxae yellow. Palps and legs yellow-brown, with grey annulations. Opisthosoma dorsally yellow-gray, with yellow cardiac mark. Posterior part of opisthosoma bears several clusters of stiff yellow setae. The venter dirty yellow. Spinnerets yellow-grey.

Male palp as shown in Figs 17–21 , 26–29 , 31 . Tibia ca. 4.5 longer than wide, with five very long spines, the longest is about 0.7 times of tibia length. Retrolateral tibial apophysis (RTA) small, non-bifurcated. Cymbium length/width ratio ca. 2.4. Tip of cymbium about 0.39 of cymbial length, sligthly shorter than bulb. Bulb 1.25 times longer than cymbial apex. Subtegulum (St) oval. Tegular length/width ratio ca. 1.4. Sperm duct (SD) clearly visible only in retrolateral view. Retrolateral margin of tegular process (TP) concave. Tegular apophysis almost round. Conductor (Cn) 2.4 times longer than wide, covering embolic tip. Embolic base with basal process (BP) located near subtegular notch (SN). Membranous extension of embolus (ME) thinner than its adjoining part. Embolus (Em) strongly curved, with a small spike (ES) ventrally. Dorsal branch (DB) of embolus as wide as ventral one (VB).

Female. Total length 14.86, carapace 6.38 long, 5.42 wide. Opisthosoma 8.32 long, 5.66 wide. Eye sizes and interdistances: AME 0.37, ALE 0.23, PME 0.46, PLE 0.48, AME–AME 0.22, AME–ALE 0.34, PME–PME 0.23, PME–PLE 0.35, AME–PME 0.20, ALE–PLE 0.25. Clypeus height at AME 0.53, at ALE 1.05. For palp and legs measurements see Table 5. For palp and legs spination see Table 6 . Coloration ( Figs 5–6 , 11 ), carapace, clypeus, chelicerae, labium and endites as in the male. Sternum and coxae brown. Palps and legs as in the male, but with more contrasting annulations. Opisthosoma as in the male, but somewhat lighter, its posterior part bears several clusters of stiff yellow setae.

Female genitalia as shown in Figs 32–35 . Epigyne slightly wider than long. Septal base (SB) almost square, with heavily sclerotized septal humps (SH). Septal stem (SS) 1.5 times shorter than septal base. Epigynal teeth (ET) parallel, as long as septal stem. Receptacles (Re) subdivided into two chambers: chamber I (RI) and chamber II (RII), both are about of the same size.

Distribution. Only known from the type locality ( Figs 46–48 ).

Figures

FIGURES 1–6. Habitus of Acantheis sergeimishenini sp. n. (1–2), and A. andreimishenini sp. n. (3–6). 1, 3—male, dorsal; 2, 4—male, ventral; 5—female, dorsal; 6—female, ventral. Scale: 2 mm.

FIGURES 7–11. General appearance (7–8), cephalic part (9) and prosoma with legs (10–11) of Acantheis sergeimishenini sp. n. (7–9), and A. andreimishenini sp. n. (10–11). 7—male, dorsal; 8—ditto, ventral; 9—ditto, anterior; 10—ditto, lateral; 11—female, lateral. Scale: 7, 8, 10, 11=1 mm. Abbreviation: CS—cluster of stiff setae.

FIGURES 12–21. Male palp of Acantheis sergeimishenini sp. n. (12–16), and A. andreimishenini sp. n. (17–21). 12, 17—whole palp, retrolateral; 13, 18—terminal part of the palp, prolateral; 14, 19—ditto, ventral; 15, 20—ditto, retrolateral; 16, 21—ditto, dorsal. Scale: 12, 17=1 mm; 13–16, 18–21=0.5 mm. Abbreviations: RTA—retrolateral tibial apophysis.

FIGURES 22–29. Bulb of Acantheis sergeimishenini sp. n. (22–25), and A. andreimishenini sp. n. (26–29). 22, 26—prolateral; 23, 27—ventral; 24, 28—retrolateral; 25, 29—apical. Scale: 0.2 mm. Abbreviations: BP—basal process of embolus, Cn— conductor, DB—dorsal branch of embolus, EB—embolic base, Em—embolus, ES—embolic spike, ME—membranous extension of embolus, SD—sperm duct, SN—subtegular notch, St—subtegulum, TA—tegular apophysis, Te—tegulum, TP—tegular process, VB—ventral branch of embolus.

FIGURES 30–35. Terminal part of the embolus (30–31) and female genitalia (32–35) of Acantheis sergeimeshenini sp. n. (30), and A. andreimishenini sp. n. (31–35). 30, 31—retrolateral; 32—intact epigyne, ventral; 33—macerated epigyne, ventral; 34—endogyne, dorsal; 35—epigyne, posterior. Scale: 0.2 mm. Abbreviations: Cn—conductor, DB—dorsal branch of embolus, Em—embolus, ET—epigynal tooth, Fo—fovea, ME—membranous extension of embolus, RI—receptacle’s chamber I, RII—receptacle’s chamber II, Re—receptacle, SB—septal base, SH—septal hump, SS—septal stem, VB—ventral branch of embolus.

FIGURES 46–48. Collecting localities of A. sergeimishenini sp. n. (circle), A. andreimishenini sp. n. (square), and A. dimidiatus Thorell, 1890 (triangle). The frame on Fig. 48 refers to the content of Fig. 47 and the frame on Fig. 47 refers to the content of Fig. 46.

FIGURES 36–44. Habitus (36), whole palp (37–38), terminal part of the palp (39–42), bulb (43) and labels (44–45) of the holotype of Acantheis dimidiatus Thorell, 1890. 36, 42—dorsal; 37, 39—prolateral; 38, 41—retrolateral; 40, 43—ventral.