Cteniogaster gen. nov.

urn:lsid:zoobank.org:act:4D38E26E-FE0F-4FD9-ADB2-9B4728BE56AD

Type species

Cteniogaster toxarchus sp. nov.

Diagnosis

Cteniogaster gen. nov. differs from all other genera of Liocranidae by the presence of a small posterior ve abdominal Feld of strong setae in males, the presence of two pairs of tenent hairs on the tarsal tips and the consistent presence of one plv and one rlv spine on mt IV. The genus differs from all other liocranid genera except Apostenus by the wide patellar indentations.

Etymology

The genus name is derived from the Greek KTENIoN, little comb, and γaSTHR, belly, referring to the small array of strong, modiFed ventral setae on the abdomen of the males of the new genus. The gender is feminine.

Description

Small (males 1.7-3.0, females 2.0-3.0) spiders. Carapace longer than wide, almost Fat but slightly higher at fovea (Fig. 9F, G), smooth (Fig. 6A), yellow or brown, covered with feathery hairs (Fig. 6B), unicoloured or with faint pattern, iridescent in some species. Distinct fovea in posterior half. MOQ widest posteriorly (Fig. 9H). Eight, six or four eyes, ringed with black. AME dark, LE pearl, PME very pale and in most species reduced, or absent. AME smaller than LE. Both eye rows straight in frontal view (Fig. 12E). Chilum single, small and subtriangular, indistinct or absent in the smaller species. Chelicerae small, yellow or brown, with a knee-shaped shaggy hair in front of fang base. Promarginal cheliceral rim with three teeth at a small distance from fang base, largest one in the middle. Retromarginal cheliceral rim with two small teeth close to fang base. Labium subtriangular, about as wide as long, with a thickened anterior rim. Endites with a lateral notch and an apical serrula, no apical hair tuft. Sternum shield-shaped, smooth, unicoloured yellow or brown, in some species with a thin border. Three pairs of weak PCT present, ICS absent.

Abdomen in different shades of grey, with an anterior row of curved strong hairs in both sexes (Figs 2N, 9A), and with broad, Fattened feathery hairs on ve surface (Fig. 6E, F). The male abdomen has a small and weak anterior do scutum and a small ve posterior patch of strong setae (Figs 2B, F, P, 3E, 6D, E, 9B, 10B). Males with ALS cylindrical and separated from each other, bearing apical EPGS (Fig. 7 E), PMS and PLS thin and slender, PLS separated by more than their length and having a dome-shaped apical segment (Fig. 7E, F). Females with non-contiguous cylindrical ALS with one major ampullate and a small number of unmodiFed piriform gland spigots, subtriangular PMS with three cylindrical and one minor ampullate gland spigot and non-contiguous subcylindrical PLS about as large as ALS bearing two cylindrical gland spigots and about a dozen aciniform gland spigots (Fig. 7A-D). Legs pale yellow to brown, unicoloured, iridescent in some species, with trichobothria with basal socket (Fig. 6G) and oval tarsal organ (Fig. 6I). Patellar indentation wide, length 2/3 of pa length in legs I to III, 1/2 of patella length in leg IV. Retrocoxal hymen present, but often pale and weak. Trochanter notch present. Tarsus IV bent with pseudoarticulations in males (Fig. 11D), and slightly bent in females. Leg formula 4123. Tarsal tips without true claw tufts but with two pairs of tenent hairs (Figs 6H, 11C, E). Metatarsus IV with one plv and one rlv spine, both in proximal half of article (Appendix 1). Minimal leg spination for the genus: males fe: palp do 0-1-1; I pl 0-0-1, do 1-1-0; II do 1-1-0; III do 1-1-2; IV do 1-1-0; pa: palp do 0-1; ti: palp pl 2-0-1; I plv 1-0-1, rlv 1-0-1; II rlv 1-0-1; III pl 1-0-1, do 1-0-0, rl 0-0-1, plv 1-1-1, rlv 0-0-1; IV pl 1-0-1, do 1-0-0, rl 1-0-1, plv 1-1-1, rlv 0-1-1; mt: I plv 1-0-0, rlv 1-0-0; II plv 1-0-0, rlv 1-0- 0; III pl 0-0-1, do 0-2-2, rl 1-0-1, ve 2-0-1; IV pl 0-0-1, do 2-2-2, rl 1-0-1, ve 2-0-1; ta: palp pl 1-0-1, do 1-0-0; females fe: palp do 0-1-1; I pl 0-0-1, do 1-1-0; II do 1-1-0; III do 1-1-2; IV do 1-1-0; pa: palp pl 1-0, do 0-1; ti: palp pl 2-0-1, do 1-0-1; I plv 1-0-1, rlv 1-0-1; II rlv 1-0-1; III pl 1-0-1, do 1-0-0, rl 0-0-1, plv 1-1-1, rlv 0-1-1; IV pl 1-0-1, do 1-0-0, rl 1-0-1, plv 1-1-1, rlv 0-1-1; mt: I plv 1-0-0, rlv 1-0-0; II plv 1-0-0, rlv 1-0-0; III pl 0-0-1, do 0-2-2, rl 1-0-1, ve 2-0-1; IV pl 0-0-1, do 2-2-2, rl 1-0-1, ve 2-0-1; ta: palp pl 2-0-1, do 1-0-0, rl 0-1-0, ve 0-0-2.

Male palp with a simple, blunt or pointed RTA, a cymbium with a spine on the distal pl edge (Figs 9C, 10C), a pl subtegulum, a short apical embolus, a membranous or sclerotised conductor and a simple, subtriangular or subrectangular MA (Fig. 11A, B). Epigyne with an anterior hood and a central depression (Figs 9E, 10E, 12C-G, K-L). Vulva with isodiametric, oval or kidney-shaped ST1 with internal spikes and ST2 with a porous glandular structure (Figs 4, 5, 8).

Distribution

The genus is known from the Taita hills in Kenya and from the East and West Usambara mountains in Tanzania. So far no specimens of Cteniogaster gen. nov. have been found outside the Eastern Arc (Fig. 13), which is a fair indication that the genus is endemic to that mountain range.

IdentiFcation Key

Females

(not known for C. nana sp. nov.)

1. Frontal hood on epigyne large, wider than half epigyne width (Fig. 5) .......................................... 2

– Frontal hood on epigyne narrow, less than one fourth epigyne width (Fig. 4) ................................ 4

2. Frontal hood as large as half epigyne width; spermathecae 1 pear shaped, oriented diagonally, spermathecae 2 oriented transversally, touching in the middle (Fig. 5E-F) ..... C. taxorchis sp. nov.

– Frontal hood almost as wide as epigyne; spermathecae 1 rounded, spermathecae 2 oriented along longitudinal axis (Fig. 5A-D) .......................................................................................................... 3

3. Frontal hood very wide and sclerotized; spermathecae 2 curved, slightly separated, not touching (Fig. 5C-D) ..................................................................................................... C. sangarawe sp. nov.

– Frontal hood less wide and hardly sclerotized; spermathecae 2 sinuous, touching in the middle (Fig. 5A-B) .......................................................................................................... C. conviva sp. nov.

4. Anterior hood in larger oval depression; spermathecae 1 piriform, widely separated (Fig. 4E-F) .... ......................................................................................................................... C. lampropus sp. nov.

– Anterior hood not surrounded by oval depression; spermathecae 1 not piriform ........................... 5

5. Spermathecae 1 very large, oval, touching in the middle (Fig. 4C-D) ............ C. hexomma sp. nov.

– Spermathecae 1 much smaller, not touching (Fig. 4A-B) ................................ C. toxarchus sp. nov.

Males

(not known for C. lampropus sp. nov., C. sangarawe sp. nov. and C. taxorchis sp. nov.)

1. Cymbium with retrolateral bulge; sclerotized conductor large and coiled; RTA large, hookshaped, sharp (Fig. 12A, B) .............................................................................................. C. conviva sp. nov.

– Without cymbial bulge; conductor small; RTA less large or straight or blunt (Figs 9C-D, 10C-D, 12A-B) ............................................................................................................................................. 2

2. RTA very short, sharp and straight (Fig. 10C-D) ............................................. C. hexomma sp. nov.

– RTA longer and blunt or curved upwards (Figs 9C-D, 12H-I) ........................................................ 3

3. RTA straight, obliquely truncated; conductor membranous (Fig. 9C-D) ........ C. toxarchus sp. nov.

– RTA curved upwards, truncated tip; conductor sclerotized (Fig. 12H-I) ................. C. nana sp. nov.