Simonia Yu & Lin, 2023

Zhang, Jianshuang, Yu, Hao & Lin, Yucheng, 2023, Simonia gen. nov., a new spider genus (Araneae, Theridiosomatidae) from Southeast Asia, ZooKeys 1185, pp. 277-294 : 277

Simonia Yu & Lin gen. nov.

Type species.

Baalzebub youyiensis Zhao & Li, 2012 (from Guangxi, China).

Etymology.

The generic epithet is named after the French arachnologist Eugène Louis Simon, in recognition of his inception of Theridiosomatidae .

Diagnosis.

Simonia gen. nov. resembles Sennin Suzuki, Hiramatsu & Tatsuta, 2022 in general shape of copulatory organs. Male palps of these two genera have similar embolic divisions with at least three bristle-like, sharp embolic apophyses; epigynes of both genera have similar spoon-shaped or equicrural triangular scape. Simonia gen. nov. can be distinguished from Sennin by a combination of following characters: cymbial outgrowth (cymbial apophysis) absent (vs present), conductor axe-shaped, almost hyaline and with vein-shaped grains (vs not axe-shaped, membranous, without vein-shaped grains), embolus long, extending to the distal part of embolic division, terminally torch-shaped, with a cylindric stalk and a multiramose apex (vs shorter and apex blunt, located at the proximal part of embolic division, embolic terminal absent), all embolic apophyses are not coiled (vs strongly curved or coiled), embolic division dorsally with large, hyaline lobe (vs embolic lobe absent) (cf. Figs 1 - 3 and Suzuki et al. 2022: figs 7, 9); epigynal plate surface distinctly wrinkled, with a distinctive transverse fold at midlength between anterior and posterior margins (vs surface slightly wrinkled, medially without the distinctive transverse fold), the anterior part of spermathecae fused (vs not fused, just only overlapped), copulatory duct indistinct, the course of the copulatory duct simple, forming a loop in the inside of copulatory bursa (vs distinct, and course more complex, with a coiled trajectory at the basal side of the spermathecae), copulatory bursa large, nearly as long as epigyne length (vs smaller or indistinct, barely longer than 1/2 length of epigynal plate) (cf. Figs 4E-G , 5C-E , 6C-E and Suzuki et al. 2022: figs 8, 10).

Description.

Small sized with body length 1.50-1.65 in males and 1.90-2.45 in females; carapace 0.83-0.96 long in males and 0.91-1.08 in females. Carapace nearly pyriform, in profile highest just behind ocular area, gradually sloping to pedicel, c. 1.35-1.45 times longer than high; carapace smooth, with long, sparse setae, yellow brown to dark brown, slightly darker anteriorly; cervical groove V-shaped, radial grooves and fovea indistinguishable. Sternum yellowish brown to dark, distinctly darker than carapace, clothed with dense setae, heart-shaped, anterior edge truncate, anterior and lateral margins with brown extensions fitting intercoxal concavities; posterior region strongly protruding between coxae IV. Female palp distally with erect, thin, dark bristles. Chelicerae slightly darker than carapace. Labium triangle shaped. Maxillae nearly trapezoidal, anterior edge straight, anterior and lateral margins slightly curved, slightly convergent posteriorly, with dense scopulae on inner margins. Legs long, uniformly coloured, slightly lighter than carapace, with darker femora and coxae I. Leg formula 1243. Abdomen ovoid, nearly as long as wide, abdominal colours and patterns variable; marginally clothed with sparse long setae, ventrally covered by fine short setae. Spinnerets brown. Male palp: same as in type species. Epigyne with small, hyaline scape (SC); epigynal plate surface distinctly wrinkled, with distinctive transverse fold (TF) at midlength between anterior and posterior margins; scape (SC) extending from posterior margin of epigynal plate, translucent; copulatory openings indistinct; copulatory duct (CD) indistinct, with simple course, forming loop in inside of copulatory bursa; spermathecae (Sp) consist of relatively large head (SS, anterior part) and slightly narrower stalk (SS, posterior part), and in addition with distinctly small base (SB, distal part) in S. sumatra sp. nov.; spermathecal heads fused, located centrally and juxtaposed; fertilization ducts (FD) acicular, membranous, located on basal surface of spermathecae; copulatory bursae (CB) represented spherical or oval sacs, large, nearly as long as epigyne length, surface hyaline, wrinkled and ribbed, bursae touching each other.

Composition and distribution.

Simonia youyiensis (Zhao & Li, 2012) from Laos, Vietnam and Guangxi in China, S. steineri sp. nov. from Laos, and S. sumatra sp. nov. from Sumatra.

Comments.

A preliminary genus-level taxonomic molecular analysis of Theridiosomatidae from Southeast Asia was carried, based on five targeted genes (two mitochondrial genes: 16S and COI; three nuclear genes: 18S, 28S, and H3). According to the results (unpublished): (1) the monophyly of the genus Simonia gen. nov. is supported; (2) this new genus is related to two genera exclusively distributed in SE Asia, Karstia and Sennin . Morphologically, the new genus is also similar to Karstia , but can be distinguished by the absence of cymbial outgrowth, presence of torch-shaped embolic terminal and large, hyaline embolic lobe, and by the fused anterior parts of the spermathecae, large copulatory bursa, as well as a set of other characters of the copulatory organs (see diagnosis of the genus above and key to theridiosomatid genera endemic to Oriental Realm below).

The type species of Simonia gen. nov., S. youyiensis was originally assigned to the Baalzebub , although it did not show typical Baalzebub features. Baalzebub is definitely not monophyletic. There is a strong possibility that Baalzebub sensu stricto contains only two species from the Neotropical Realm: B. baubo and B. albonotatus (Petrunkevitch, 1930). These Neotropical Baalzebub species share the following distinctive suite of characters, here contrasted with the corresponding condition in Simonia gen. nov.: 1) embolic apophyses spatulate, thick and blunt (vs bristle-like and slender, apically sharp); 2) embolus claw-shaped, not branched (vs torch-shaped, with a cylindric stalk and a multiramose apex); 3) embolic lobe absent (vs present); 4) conductor not axe-shaped, surface smooth (vs axe-shaped, surface with many vein-shaped grains); 5) scape large, at least longer than 1/2 length of epigynal plate (vs small, no more than 1/4 length of epigynal plate); 6) epigynal plate surface smooth (distinctly wrinkled, with a distinctive transverse fold); and 7) copulatory bursa surface smooth, small, less than 1/2 length of epigynal plate (surface wrinkled and ribbed, large, as long as length of epigyne) (cf. Coddington 1986: figs 161-164, 183, 184, 186, 187 and Figs 1 - 3 , 4E-G , 5C-E , 6C-E ). In view of the above-mentioned facts, it is currently impossible to discern any obvious derived features that could indicate a close relationship between S. youyiensis and the genus Baalzebub sensu stricto, leaving no doubts that our new combination and the establishment of a new genus are correct.

Figures

Figure 1. Male palp of Simonia youyiensis A prolateral B retrolateral C dorsal D ventral. Abbreviations: Co = conductor; CL = cymbial lobe; Cy = cymbium; ED = embolic division; MA = median apophysis; Pc = paracymbium; SCy = cymbial setae; St = subtegulum; Te = tegulum. Scale bars: 0.2 mm (A-D).

Figure 3. Male palpal sclerites of Simonia youyiensis, cited from Zhang and Lin (2016) A bulb, prolateral B embolic division, ventral C conductor, ventral D cymbium, retrolateral. Abbreviations: Co = conductor; CL = cymbial lobe; EA = embolic apophysis; ED = embolic division; EL = embolic lobe; ET = embolic terminal; MA = median apophysis; Pc = paracymbium; SCy = cymbial setae; St = subtegulum; Te = tegulum. Scale bars: 0.1 mm (A-D).

Figure 4. Simonia youyiensis, male habitus (A, B), female habitus (C, D) and epigyne (E-G) A dorsal B ventral C dorsal D ventral E intact, ventral F cleared, ventral (blue dashed line showing the anterior margin of the epigynal plate) G cleared, dorsal (green dashed line showing schematic course of copulatory duct). Abbreviations: CB = copulatory bursa; CD = copulatory duct; FD = fertilization duct; Sc = scape; SH = spermathecal head; SS = spermathecal stalk; Sp = spermatheca; TF = transverse fold of epigynal plate. Scale bars: 0.5 mm (A-D); 0.2 mm (E-G).

Figure 5. Holotype female of Simonia steineri sp. nov., habitus (A, B) and epigyne (C-E) A dorsal B ventral C intact, ventral D cleared, ventral (blue dashed line showing the anterior margin of the epigynal plate) E cleared, dorsal (green dashed line showing schematic course of copulatory duct). Abbreviations: CB = copulatory bursa; CD = copulatory duct; FD = fertilization duct; Sc = scape; SH = spermathecal head; SS = spermathecal stalk; Sp = spermatheca; TF = transverse fold of epigynal plate. Scale bars: 0.5 mm (A, B); 0.2 mm (C-E).

Figure 6. Holotype female of Simonia sumatra sp. nov., habitus (A, B) and epigyne (C-E) A dorsal B ventral C intact, ventral D cleared, ventral (blue dashed line showing the anterior margin of the epigynal plate) E cleared, dorsal (green dashed line showing schematic course of copulatory duct). Abbreviations: CB = copulatory bursa; CD = copulatory duct; FD = fertilization duct; SB = spermathecal base; Sc = scape; SH = spermathecal head; SS = spermathecal stalk; Sp = spermatheca; TF = transverse fold of epigynal plate. Scale bars: 0.5 mm (A, B); 0.2 mm (C-E).