Knoflachia, Marusik & Eskov, 2024

Marusik, Yuri M. & Eskov, Kirill Y., 2024, A new monotypic genus of cobweb spiders from the Russian Far East (Araneae, Theridiidae), ZooKeys 1195, pp. 219-238 : 219

publication ID

https://dx.doi.org/10.3897/zookeys.1195.118632

publication LSID

lsid:zoobank.org:pub:D1D346D3-EFB2-48F9-B729-DDA31A6E8270

persistent identifier

https://treatment.plazi.org/id/B5704C12-015F-4408-A670-CE9CB44CA6CB

taxon LSID

lsid:zoobank.org:act:B5704C12-015F-4408-A670-CE9CB44CA6CB

treatment provided by

ZooKeys by Pensoft

scientific name

Knoflachia
status

gen. nov.

Knoflachia gen. nov.

Etymology.

Named after Barbara Knoflach (Innsbruck, Austria), an outstanding expert in theridiid taxonomy. Gender is feminine.

Type species.

Knoflachia kurilensis sp. nov.

Diagnosis

(comparison of the generotype). The new genus is most similar to Anelosimus Simon, 1891 in both copulatory organ characters (cymbial mesial margin with an incision; conductor with a groove for a distal portion of the spiral embolus) and somatic characters (male leg I extremely elongated, femur longer than carapace). It differs from the latter by: 1) carapace uniformly orange, abdomen uniformly black (vs carapace pale coloured with dark medial strip, abdomen with characteristic leaf-shaped pattern); 2) carapace cuticle rugose (vs smooth); 3) fovea transversal (vs rounded); 4) pars cephalica mildly sloping (vs not elevated, flat); 5) eye area not projected (vs projected); 6) male prosomal stridulatory ridges (PSR) separated into two patches (vs continuous); 7) female PSR absent (vs weak); 8) sternum equilateral triangle (vs elongated orthogonal); 9) labium fused with sternum (vs separated by distinct seam); 10) bristles of the tarsus IV comb flattened and straight (vs conical and hooked); 11) tarsus IV central claw subequal to laterals in length, thickness and shape (vs elongated, thin and S-shaped); 12) tarsal organ clearly proximal: 0.33-035 (vs slightly distal: 0.55-0.60 to slightly proximal: 0.45); 13) abdominal stridulatory pick row (SPR) setal bases strongly elongated, keeled in male, and dome-like in female (vs moderately elongated and rounded in both sexes); 14) male palpal tibia spoon-like, extremely enlarged, covers more than a half of the bulb (vs cyathiform, usual for theridiids); 15) male palpal tibia with only 2 retrolateral trichobothria (vs 2 retrolateral and 1 prolateral trichobothria); 16) cymbial mesial margin incision fold-like (vs semicircular notch); 17) the tegular apophysis (Ta) is a curved spine (vs not pointed); 18) conductor semimembraneous, its groove forming a sheath for a distal portion of the embolus (vs not membranous, its grove for embolus more shallow); 19) tip of embolus unmodified (vs. modified); 20) epigynal plate smooth (vs ridged); 20) copulatory openings located in two foveae separated by a septum (vs. foveae and septum absent); 21) each fovea with a spiral ridge (epigynal plate with transverse ridges); 22) copulatory ducts (Cd) coiled (vs. not coiled); and 23) receptacles dumbbell-shaped located inside loops of copulatory ducts (vs. oval, not surrounded by copulatory ducts).

Description.

Small (1.8-2.85) brightly coloured (orange and black) with unmodified carapace and abdomen in both sexes (Fig. 1A-F View Figure 1 ) and modified leg I in male (Figs 1D, F View Figure 1 , 2A, B View Figure 2 ).

Carapace - rounded, almost as wide as long, moderately high, pars cephalica slightly elevated, clypeus vertical; fovea shallow, transversal (Figs 2C View Figure 2 , 3A, C, D View Figure 3 ); 8 medium-sized eyes, AME same as others (ca 1/3 of clypeus height), lateral eyes adjacent, eye area not projected (Figs 2C View Figure 2 , 3A, C View Figure 3 ); carapace pars stridens consist of two separated patches of regular parallel fine ridges in male (Fig. 4 View Figure 4 , B) indistinct under light microscope (Fig. 2C View Figure 2 ) and completely absent in female (Fig. 4C View Figure 4 ,); carapace cuticle rugose, setal bases elevated (Fig. 3C, D View Figure 3 ).

Sternum - almost equilateral triangle (Figs 1E View Figure 1 , 3B View Figure 3 ); sternal cuticle rugose, setal bases elevated (Fig. 3E View Figure 3 ).

Labium - sub-rectangular, completely fused to sternum (Fig. 3B, E View Figure 3 ).

Chelicera - unmodified, without humps; promargin in both sexes with 3 teeth (2 basal fused) and pair of raised, fused setal sockets adjacent to fang base (Fig. 3E, F View Figure 3 ); cheliceral cuticle rugose, setal bases elevated (Fig. 3F View Figure 3 ).

Legs - Leg formula 1243 in males and 1423 in females, leg I of male extremely long and stout, Fe I can be almost 1.5 times longer than carapace length (Figs 1A-D View Figure 1 , 2A View Figure 2 ) in large specimens; distal part of femur 1.5 times wider than proximal; metatarsus and tibia I in large specimens with 2 ventral rows of tubercles, surmounted by robust blunt suberect macrosetae (Figs 2A, B View Figure 2 , 5A View Figure 5 ); bristles of tarsus IV theridiid comb flattened and straight, not hook-like (Fig. 5B, C View Figure 5 ); tarsus IV central claw subequal to laterals by length, thickness and shape in both sexes, and not distinguished from claws of other leg pairs (Fig. 6A-C View Figure 6 ); metatarsal trichobothria 1-1-1-0, bothria dome-like (Fig. 5F View Figure 5 ), usual for theridiids ( Eskov and Marusik in prep.); tarsal organ clearly proximal (0.33-0.35), its opening large, more than setal sockets (Fig. 5D, E View Figure 5 ); leg cuticle imbricate (Fig. 5E View Figure 5 ).

Female palp - full-segmented; palpal tibia with 2 trichobothria; palpal claw simple, non-semipalmate, strongly dentated (Fig. 6D View Figure 6 ).

Abdomen - more or less globular; pedicel area with suprapedicillate dorsal (11 o’clock) proprioceptor setae (Figs 4F View Figure 4 , 7A View Figure 7 ); stridulatory pick row (SPR) lateral of pedicel, regular, not curved, consist of few (<7) setae (Fig. 4D, F View Figure 4 ); SPR setal bases strongly elongated and keeled, tetragonal in profile, with setae vertically protruded from its middle portion in male (Fig. 4D, E View Figure 4 ), and rounded, dome-like in female (Fig. 4F View Figure 4 ); epiandrous gland spigots arranged in a pair of distinct depressions (sockets), 3 spigots per socket (Fig. 5D View Figure 5 ); wide tracheal spiracle near spinnerets, not straight, with pair of lobes (Sl, Fig. 7C View Figure 7 ); colulus absent, but median pair of colular setae persists (Fig. 7C View Figure 7 ); ALS piriform field small, less than 20 spigots (Fig. 8A, B, E View Figure 8 ); PLS posterior AG spigot enlarged and flattened, subquadrate in profile (Fig. 8A, C View Figure 8 ); PMS with 3 spigots (1 mAP + 2 AC) in male (Fig. 8E, F View Figure 8 ) and 4 spigots (1 mAP + 2 AC + 1 CY) in female (Fig. 8A, E View Figure 8 ); abdominal cuticle fingerprint (Fig. 7A View Figure 7 ), booklung cuticle smooth.

Male palp - patella short, almost as wide as long, 2.4 times shorter than tibia; tibia spoon-like, extremely enlarged, ca 2/3 of cymbial length, covers more than half of proximal part of bulb (Figs 9A View Figure 9 , 10A View Figure 10 ), with 2 retrolateral trichobothria (Fig. 10D View Figure 10 ) and with several setae on its inner surface (probably artifact) (Fig. 11A View Figure 11 ) and; cymbium 1.9 times longer than wide, with round proximal part and finger like tip slightly bent retrolaterally; cymbial mesial margin distally with small bulge (Sb) (when observed with light microscope: Fig. 9A-C View Figure 9 ), which is dissected longitudinally by fold-like excavation (when observed with SEM: Figs 10B, C View Figure 10 , 11D View Figure 11 ); cymbial ectal margin distally with groove-like cymbial hood (Ch) (Fig. 11D View Figure 11 ). Bulb as long as wide, with relatively small tegulum (Te), tegular apophysis (Ta) appears as simple curved, weakly sclerotized spine (Figs 9A View Figure 9 , 10A, B View Figure 10 , 11B, D View Figure 11 ); elongated hyaline conductor (Co) with groove serving as sheath for distal portion embolus (Fig. 10B, C View Figure 10 ); embolus filamentous coiled forming loop ca. 400°, (Fig. 11B View Figure 11 ); radix (Ra) and median apophysis (Ma) (we are not sure about homology) in unexpanded palp completely hidden by enlarged retroventral part of tibia (Figs 10A View Figure 10 , 11C View Figure 11 ); median apophysis (?) with 2 arms: large spine like posterior (Mp) and small prolateral (Pm).

Epigyne - as seen by light microscope (Fig. 9D, E View Figure 9 ): epigynal plate about as long as wide, weakly sclerotized, with pair of round membranous parts (Rm) separated by thin septum; endogyne with long coiled weakly sclerotized copulatory ducts (Cd) and dumbbell-shaped receptacles (Re) standing perpendicular to epigynal plate behind Rm. As seen by SEM (Fig. 7A, B View Figure 7 ): epigyne with kind of foveae, well delimited by latero-posterior rim (Lp) and septum (Sp). Rim and septum forming guide groove (Gg) for embolus, anteriorly from septum Gg shallower, Gg forms 2 coils (about 720°) and terminates in copulatory opening (Oc).

Composition and distribution.

Only the type species, K. kurilensis sp. nov., known only from the type locality (South Kurile islands, Kunashir Island: Fig. 12 View Figure 12 ). The future records of this genus are surely anticipated in other Far East regions such as Hokkaido.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Theridiidae