Amicactenus, Henrard & Jocqué, 2017

Henrard, Arnaud & Jocqué, Rudy, 2017, Morphological and molecular evidence for new genera in the Afrotropical Cteninae (Araneae, Ctenidae) complex, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 180 (1), pp. 82-154 : 97-100

AMICACTENUS GEN. NOV.

http://zoobank.org/ urn:lsid:zoobank.org:act:C9E86623-A29B-4237-A033-808421CE2676

Type species

Amicactenus pergulanus (Arts, 1912) . Designated here. Detailed description in Steyn et al. (2003).

Etymology

The generic name is a combination of ‘ amicus ’ (friendly) and ‘ Ctenus ’. It refers to the docile behaviour of the species belonging to the genus. The gen- der of the genus is masculine.

Diagnosis

Amicactenus species can be distinguished from the remaining Ctenidae by the presence of the particular modification of Mt IV on the legs of the male, consisting in a dense field of nodules (figs 32, 38, 57, 62, 63 in Steyn et al., 2003) [character 76(2)] in combination with an incised MA. Epigyne with a broad anterior part with a lateral flap on either side of a fairly densely setose central part.

Description

Ecribellate ctenids. Medium to large size, body length (males and females) 9 – 24. Carapace piriform ( Figs 7A, C; S 2A, S 3A, S 4A ), dark brown to black with pattern of pale stripes; thoracic groove longitudinal, in the posterior third. Chilum divided. Clypeus with long erect black bristles. Ctenid eyes pattern 2 – 4 – 2, with the anterior and posterior row recurved in dorsal view. Eyes round, except oval anterior lateral eyes. Chelicerae dark brown, with long erect hairs; promargin with three teeth, the median higher than the laterals; retromargin with four teeth of equal size; intermarginal denticles present. Endites brown with lighter apical area, external lateral margin excavated, distally bearing dense apical scopulae and subapical serrula. Labium brown, distally rounded bearing dense apical scopula. Sternum medium to dark brown, shield-shaped, not extending between coxae IV. Legs brown. Male legs more elongate and slender than female legs. Mt IV elongate, with dense, ventrolateral field of nodules ( Fig. S3B, C ). Trochanters notched. Abdomen oval ( Fig. 7B, D; S 2A, S 3A, S 4A, B ), with dispersed setae forming specific pattern often with pairs of dark spots; ventral coloration pattern species-specific, often dark. Male palp ( Figs 8A, B, 9A – C; S 2F, G, S 3D – F, S 4C, D ): tibia with ventral process on distal margin; RTA bifid, originating at short distance from distal margin; cymbium with elongate tip, without horn at base; subtegulum prolateral; tegulum oval; MA with dorsal concavity, short, widened and rounded at extremity, prolateral margin deeply incised; embolus wide, short, curved apex provided with laminar process; locking lobes present; conductor c-shaped hyaline. Epigyne ( Figs 8C, 10A – D; S 2B, C, S 3G, H, S 4E ): divided in MS and two lateral sectors LS; MS with broad frontal part with two lateral flaps, centrally constricted, posterior part widened; LS with sharp, curved LP; vulva ( Figs 10E, F; S 2D, E, S 4F, G ) with spermathecae oval, sometimes slightly constricted.

Composition

Four species: A. eminens ( Fig. S2A – G ), A. pergulanus (Arts, 1912) ( Fig. S4A – G ), A. fallax (Steyn & Van der Donck, 2003) ( Fig. S3A – H ), A. mysticus sp. nov.

Distribution

Rainforest of Central and West Africa.

Figures

Figure 2. Phylogeny reconstruction based on the ctenid spiders sequenced during this study only (= ’ctenids only’ alignments). Support values from the different analyses run on the combined alignment and on each marker are summarized here on the majority rule consensus Bayesian tree. Squares at nodes indicate the analysis method (MB, Bayesian Inference performed with MrBayes; ML, maximum likelihood). Colour of squares represents support values: strong support in black (MB ≥ 0.95; ML ≥ 0.70), moderate support in grey (0.75 ≤ MB <0.95; 0.60 ≤ ML <0.70), weak support in white (0.50 <MB <0.75; 0.50 <ML <0.60) and no support in white with diagonal line. No squares are shown at nodes without any support.

Figure 3. Phylogenetic reconstruction based on the ‘ctenids only’ alignment with addition of morphological data. The majority rule consensus Bayesian tree is shown. Support values (bootstraps and posterior probabilities) are shown at nodes as follows: ML/MB. Values below 0.5 are not shown (stars).

Figure 4. Phylogenetic reconstruction based on the ctenid spiders sequenced during this study with additional sequences from GenBank (Table 2, further explanation in the text). The majority rule consensus Bayesian tree is shown. Support values (bootstraps and posterior probabilities) are shown at nodes as follows: ML/MB. Values below 0.5 are not shown (stars).

Figure 7. Amicactenus mysticus sp. nov.: A, B, Ht male (DNA-N06, MRAC 238226); C, D, Pt female (MRAC 238919); A, male carapace, dorsal view; B, male abdomen, dorsal view; C, female carapace, dorsal view; D, female abdomen, dorsal view. Scale bars = 2 mm.

Figure 9. Amicactenus mysticus sp. nov., Ht male (DNA-N06, MRAC 238226): A, palp, ventral view; B, as previous, retrolateral view; C, male palpal tibia, retrolateral view. C: conductor, E: embolus, MA: median apophysis, RTA: retrolateral tibial apophysis, Teg: tegulum. Scale bars A, C = 0.5 mm; B = 1 mm.