Ceratinella playa Cokendolpher, Torrence, Smith & Dupérré, 2007

Cokendolpher, James C., Torrence, Shannon M., Smith, Loren M. & Dupérré, Nadine, 2007, New Linyphiidae spiders associated with playas in the Southern High Plains (Llano Estacado) of Texas (Arachnida: Araneae), Zootaxa 1529, pp. 49-60 : 52-54

Ceratinella playa Cokendolpher, Torrence, Smith & Dupérré , new species

( Figs 4–6 , 8 , 10–16 )

Type material.— HOLOTYPE male: U.S.A.: Texas: Briscoe County: Playa BR13, 15 June 2005, S.M. Torrence, L.M. Smith, N34°32'12.336" W101°17'37.212" (TTU-Z 29,902). ALLOTYPE female: U.S.A.: Texas: Briscoe County: Playa Br59, N34°24'40.896" W101°17'16.54800", 22 June 2005, S.M. Torrence, L.M. Smith, (TTU-Z 29,903).

Diagnosis.—The unmodified cephalic region, coiled pedipalpal embolus, distally arising tibial apophysis, cheliceral dentition pattern–promargin 5–6, retromargin 2, and cheliceral fang not double-curved separate this species from all Ceratinella , Ceraticelus , and Idionella .

Description.— Male (Holotype, Fig. 8 ): Total length: 1.54 mm; carapace length: 0.68 mm; carapace width: 0.51 mm. Carapace smooth to slightly rugose, cephalic region unmodified, without pits, brownishorange infuscate with dark brown ( Fig. 4 ). Sternum wide brownish-orange infuscate, smooth, coxae of legs IV widely separated, posterior of sternum broadly truncate, its flat end about 1/3 sternum maximum width ( Fig. 5 ). Chelicerae uniformly colored as carapace. Cheliceral stridulatory file not evident with dissection microscope (visible as striae at 200X). Cheliceral fang straight, not shortened, unmodified; promargin with 1 large and 5 smaller denticles ( Fig. 4 ), retromargin with 2–3 smaller denticles ( Fig. 5 ) (small denticles on both margins equal in size). Abdomen unpatterned, scutum 0.75 mm long, remainder of abdomen 0.12 mm long. Scutum amber to orange with numerous large granules (anterior granules pointed and hooked) tipped with long setae ( Fig. 6 ), dorsal scutum extends over anterior of abdomen to near the pedicel. Epigastric scutum extends up only to pedicel. Abdomen pale tan, sclerotized and amber colored around spinnerets ventrally. Legs light amber; tibia II–IV with one dorsal macroseta; TmI 0.49, TmIV absent. Pedipalpal tibia with a thick, stout, curved apophysis ( Figs 10–12 ); tibial apophysis with a fine field of minute denticles on mesal side of tip (visible at 400X); embolus thin, coiled basally, not separate from ductule, no break or prong in distal half ( Fig. 10, 11 ), distally with final loop, distal loop not recurved upon itself at an acute angle (more gently rounded); radical tailpiece elongated and spiraled throughout ( Fig. 10 ); protegulum white to light gray colored, contrasting with darkened sclerotized parts; other details of the pedipalp are as in Figs 10, 11 .

Female: Total length: 1.54 mm, carapace length: 0.75 mm, carapace width: 0.46 mm. Carapace colored like legs, chelicera slightly darker. Carapace setal pattern with 4 erect setae along midline. Sternum colored as carapace but more infuscate with dark brown. Cheliceral promargin with 2 large and 3 small denticles and retromargin with 2 denticles. Cheliceral stridulatory file not visible with dissection microscope (visible as striae at 200X). Abdomen length 0.79 mm, seta-crowned tubercles much less pronounced than in male, uniformly colored (no pattern nor maculations) dark brown, densely covered with semi-erect setae; without scutum. Legs light yellow to amber; tibia II–IV with one dorsal macroseta each, tibia I with 2 smaller macrosetae; TmI 0.44, TmIV absent. Posterior portion of the epigynal plate sclerotized as in Fig. 13 . Spermathecae only faintly visible through the cuticle and not extending beyond the epigynal plate ( Figs 14–16 ). Spermathecae oval, fertilization ducts strongly curved inwards, copulatory ducts short and curled/looped ( Figs 14–16 ).

Distribution.—Thus far only collected within about an 11 km radius of Silverton, Briscoe County, Texas, U.S.A.

Habitat.— The canopy of emergent aquatic vegetation within playa wetlands. The type locality had primarily grasses when it was photographed ( Figs 2, 3 ), a year before the collections were made.

Etymology.—The specific name is a noun in apposition to the genus, Ceratinella ; from the western U.S.A. English " playa " meaning shallow depressional wetlands in the Southern High Plains, U.S.A. (not the Spanish " playa " = beach). The name refers to discovering this species in playas.

Figures

FIGURES 4 – 7. Males: 4 – 6, Ceratinella playa new species, 4, anterior view of carapace and chelicera; 5, ventral view of pedicel to chelicera; 6, closeup view of anterior edge of dorsal scutum of abdomen; 7, Erigone denticulata Chamberlin & Ivie cephalothorax and appendages anteriolateral view; 7, Scale bars = 0.1 mm, except Fig. 6 = 0.05 mm.

FIGURES 8 – 9. Habitus of males: 8, Holotype of Ceratinella playa new species; 9, Erigone denticulata Chamberlin & Ivie. Scale bars = 0.25 mm.

FIGURES 10 – 16. Male holotype and female allotype Ceratinella playa new species: 10, distal end of pedipalpus of male, ventral view; 11, distal end of pedipalpus of male, retrolateral view; 12, pedipalpal tibia of male, dorsal view; 13, epigynum, ventral view; 14, spermathecae, ventral view; 15, spermathecae, dorsal view; 16, spermathecae, posterior view. Abbreviations used: CO copulatory opening, CD copulatory ducts, E embolus, FD fertilization ducts, PC paracymbium, PT protegulum, PTA pedipalpal tibia apophysis, S spermatheca, SPT suprategulum, ST subtegulum, TE tegulum, TP radical tailpiece. Terminology follows Hormiga (2000). Scale bars = 0.05 mm.

FIGURES 1 – 3. 1, Aerial view of some playa lakes on the flat landscape of the Southern High Plains (Llano Estacado) of Texas (photograph by Wyman Meinzer, courtesy of the U. S. Fish and Wildlife Service). 2, Panoramic view (stitched from four photographs) from the dirt road west of Playa BR 13 looking east on the High Plains of Texas. Note the very flat landscape and lack of larger vegetation [photographs by Jo-Szu (Ross) Tsai] during August 2004. 3, Closeup of the left corner of Fig. 2 showing the short vegetation (mostly grasses); pick-up truck not cropped to indicate size of playa [photograph by Jo-Szu (Ross) Tsai].