Amauropelma mariae, Omelko & Fomichev, 2024

Omelko, Mikhail M. & Fomichev, Alexander A., 2024, A survey of the Sumatran Ctenidae (Araneae). 3. Amauropelma mariae sp. n., one of the tiniest species of the genus, Zootaxa 5474 (2), pp. 173-180 : 174-178

Amauropelma mariae sp. n.

Figs 1–20

Type. INDONESIA: Sumatra Island : Aceh Prov.: Holotype: ♂ ( FEFU), Ketambe Vil. [03°41′N, 97°39′E], 400– 500 m, 1988 (precise date unknown), unknown collector. Paratypes: ♂ ( ISEA), 1♀ ( FEFU), together with the holotype .

Etymology. The specific name is a matronym in honor of Maria М. Omelko (Vladivostok, Russia), an elder daughter of the senior author on the occasion of her 10th anniversary.

Diagnosis. Males of the new species might be easily distinguished from most congeners, except A. saraburi Li & Yao, 2022 , A. anzses Raven & Stumkat, 2001 , A. monteithi Raven & Stumkat, 2001 , and A. mossman Raven & Stumkat, 2001 by the very short retrolateral tibial apophysis (RTA) (length ca. 1/5 of tibia width vs. 1/3–1/2). Amauropelma mariae sp. n. differs from the A. saraburi and A. anzses by the absence of retro-proximal cymbial outgrowth (vs. presence; cf. fig. 6 and 6b in Chu et al. 2022b, and fig. 9b in Raven et al. 2001); from A. monteithi and A. mossman by single tip of RTA (vs. bifurcated; cf. fig. 6 and figs 22d, 24d in Raven et al. 2001).

By general shape of its epigyne, the female of Amauropelma mariae sp. n. is similar to several Australian species such as A. claudie Raven & Stumkat, 2001 , A. leo Raven & Stumkat, 2001 , A. monteithi Raven & Stumkat, 2001 , A. mossman Raven & Stumkat, 2001 , A. pineck Raven & Stumkat, 2001 , A. torbjorni Raven & Gray, 2001 , A. trueloves Raven & Stumkat, 2001 , and A. wallaman Raven & Stumkat, 2001 . It is also similar to A. annegretae Jäger, 2012 , known from Laos. The new species can be distinguished from all of those species except A. claudie and A. leo by the distance between the tips of the lateral teeth (LT) being greater than the width of the epigynal plate (vs. shorter). A. mariae sp. n. might be further differentiated from the two latter species by the straight anterior edge of its epigyne (vs. concave).

Description. Male ( Figs 1–2 ), holotype. Total length 4.06. Carapace 2.17 long, 1.65 wide. Opisthosoma 1.85 long, 1.17 wide. Carapace light brown with dark brown edges, median band almost invisible. Lateral bands yellowish. Fovea thin, brown. Chelicerae light brown with 3 promarginal and 4 retromarginal teeth. Sternum light brown without pattern. Labium and maxillae light brown. Dorsum of opisthosoma grayish with a pattern consisting of yellow cardiac mark, a pair of longitudinal stripes next to it and series of transversal stripes. Lateral sides of abdomen yellow brown with light gray spots. Venter of opisthosoma yellow with indistinct grayish spots. Spinnerets light brown.

Eye diameters: AME 0.11, ALE 0.10, PME 0.14, PLE 0.13; interdistances: AME–AME 0.03, AME–ALE 0.07, PME–PME 0 (eyes touching each other), PME–PLE 0.11, AME–PME 0.02, ALE–PLE 0.03. Clypeus height at AME 0.05, at ALE 0.13.

For palp and leg measurements see Table 1 . Palp joints light brown, cymbium somewhat darker than other segments. Segments of legs light brown (metatarsi III–IV slightly darker than other joints), without annulation. For palp and leg spination see Table 2 .

Palp as shown in Figs 5–14 . Distal part of femur and retrolateral side of patella covered with numerous, tiny spines. Retrolateral patellar apophysis absent. Tibia 1.91 times longer than wide. Tibia with tiny, spine-like retrolateral tibial apophysis (RTA), positioned at right angle to longitudinal axis of tibia and ventral tibial apophysis (VTA). Cymbium length/width ratio 1.64. Cymbium with large bilobated (in prolateral view) prolateral cymbial bulge (PCB). Retrolateral cymbial bulge absent. Tegular apophysis (TA) small, cup-shaped, located almost in middle of bulb. Sperm duct (SD) long, starts at 12 o’clock. Embolus (Em) flat in prolateral view, starting at 8-o’clockposition from tegulum (Te), with small extension (EE) basally. Conductor (Cn) membranous, with its base at 12:30 position.

Female ( Figs 3–4 ). Total length 4.58. Carapace 2.28 long, 1.76 wide. Opisthosoma 2.19 long, 1.40 wide. Coloration as in the male. Chelicerae with 3 promarginal and 5 (1 of them tiny, poorly visible) retromarginal teeth.

Eye diameters: AME 0.10, ALE 0.10, PME 0.14, PLE 0.14; interdistances: AME–ALE 0.11, PME–PLE 0.14, AME–PME 0.04, ALE–PLE 0.08; AME–AME and PME–PME are not measured, because some eyes of the single female are underdeveloped due to deformity. Clypeus height at AME 0.05, at ALE 0.14.

For palp and legs measurements see Table 3 . For leg spination see Table 4 .

Epigyne as shown in Figs 15–18 . Epigynal field with two slit sense organs anterior to epigynal plate. Epigynal plate (EP) width/length 0.58/0.41, anterior width/posterior width 0.40/0.22; posterior part with almost straight lateral margins (LM). Lateral tooth (LT) large with wide base, its distal part of posteriorad. Epigyne with two diagonal internal folds (IF). Receptacles (Re) round, separated from each other by somewhat less than half of their diameter. Fertilisation ducts (FD) laminar, mediad.

Distribution. Type locality only ( Figs 19–20 ).

Figures

FIGURES 1–4. Habitus of Amauropelma mariae sp. n., male (1–2), female (3–4). 1, 3—dorsal; 2, 4—ventral. Scale: 1 mm.

FIGURES 5–14. Male palp (5–9), palp patella (10) and bulb (11–14) of Amauropelma mariae sp. n. 5, 11—prolateral; 6, 12—ventral; 7, 9, 10, 13—retrolateral; 14—anterior. Scale: 0.2 mm (5–9), 0.1 mm (10–14). Abbreviations: Cn—conductor, EE –embolic extension, Em—embolus, PCB—prolateral cymbial bulge, RTA—retrolateral tibial apophysis, SD—sperm duct, Te—tegulum, TA—tegular apophysis, VTA—ventral tibial apophysis.

FIGURES 15–18. Epigyne of Amauropelma mariae sp. n., intact (15) and macerated (16–18). 15, 16—ventral; 17—dorsal; 18—posterior. Scale bar: 0.1 mm. Abbreviations: CO—copulatory opening, EP—epigynal plate, IF—internal fold, FD— fertilization duct, LM—lateral margin, LT—lateral tooth, Re– receptacle.

FIGURES 19–20. Distribution records of Amauropelma spp. (nearby localities in Australia are combined). The frame on Fig. 19 refers to the content of Fig. 20. A. beyersdorfi (1); A. staschi (2); A. ekeftys (3); A. mariae sp. n. (4); A. phangnga (5); A. krabi (6); A. yunnan (7); A. saraburi (8); A. hoffmanni (9); A. annegretae (10); A. jagelkii (11); A. guangxi (12); A. matakecil (13); A. claudie, A. gordon, A. leo, A. mcilwraith (14); A. undara (15); A. anzses, A. monteithi, A. mossman, A. pineck, A. rifleck, A. torbjorni, A. trueloves (16); A. hasenpuschi, A. pineck (17), A. bluewater, A. gayundah, A. wallaman (18).

Tables

TABLE 2. Legs spination of male of Amauropelma mariae sp. n.

	Fe	Pa	Ti	Mt
Leg I	3d 2p	0	1p 2-2-2-2-2v	2-2-2v
Leg II	3d 1p 1(0)r	0	1p 2-2-2-2-2v	1p 2-2-2v
Leg III	3d 3p 1r	1r	2d 2p 2r 2-2-2v	4p 4r 2-2-2v
Leg IV	3d 3p 2r	1r	2d 2p 2r 2-2-2v	4p 5r 2-1-1-2v

TABLE 3. Palp and legs measurements of female of Amauropelma mariae sp. n.

	Fe	Pa	Ti	Mt
Leg I	3d 2p	0	1p 2-2-2-2-2v	2-2-2v
Leg II	3d 1p 1(0)r	0	1p 2-2-2-2-2v	1p 2-2-2v
Leg III	3d 3p 1r	1r	2d 2p 2r 2-2-2v	4p 4r 2-2-2v
Leg IV	3d 3p 2r	1r	2d 2p 2r 2-2-2v	4p 5r 2-1-1-2v

TABLE 4. Legs spination of female of Amauropelma mariae sp. n. Fe Pa Ti

	Fe	Pa	Ti	Mt
Leg I	3d 2p	-	2-2-2-2-2-2v	2-2-2v
Leg II	3d 1p	-	2-2-2-2-2v	2-2-2v
Leg III	3d 3p 1r	1r	2d 2p 3r 2-2-2v	4p 5r 2-2-2v
Leg IV	3d 1(3)p 1r	1r	2d 2p 3r 2-1-2-2v	4p 4r 2-2-2v