Amicactenus mysticus, Henrard & Jocqué, 2017

AMICACTENUS MYSTICUS View in CoL SP. NOV.

( FIGS 7A – D View Figure 7 , 8A – C, 9A – C View Figure 9 , 10A – F)

http://zoobank.org/ urn:lsid:zoobank.org:act:A1EF5C54-53BD-4D42-A39A-217B000D4AB1

Type material

Holotype, male: GUINEA, Mt. Nimba, Foret de Seringbara , 7 ° 39 0 N, 8 ° 26 0 W, 601 m asl, 8.X.2008, in secondary forest, hand collecting on lower vegetation and dead tree trunks, Van den Spiegel D. ( DNA-N06 , MRAC238226 View Materials ). GoogleMaps

Paratypes: GUINEA: 2 ♂: on abandoned termite mound, further data as holotype ( DNA-N59 , MRAC 240402 View Materials ) GoogleMaps ; 1 ♂: 6.X.2008, further data as holotype ( MRAC225788 View Materials ) GoogleMaps ; 1 ♀: Mt. Nimba, Foret de Seringbara , 7 ° 39 0 N, 8 ° 26 0 W, 23.II.2012, secondary forest, hand collecting, Van den Spiegel D., Henrard A., Allard C., Bimou P. & Sidibe M. ( DNA-N08 , MRAC 238919 View Materials ) GoogleMaps .

Other material

LIBERIA: 1 ♀: Bong Range Forest , 6 ° 49 0 N, 10 ° 17 0 W, 170 m asl, 15.II.2006, pitfalls in rainforest, Flomo D. ( MRAC 243295 View Materials ) GoogleMaps ; 1 ♀: 8.VII.2005, in rainforest, night catch, further data as previous ( MRAC 243294 View Materials ) GoogleMaps ; 1 ♂: as previous, 8.VIII.2005 ( MRAC 240404 View Materials ) ; 1 ♂: as previous, I.2006, pitfalls in rainforest ( MRAC 219412 View Materials ) ; 1 ♂: as previous ( MRAC 240403 View Materials ) .

Etymology

The position of the species was somewhat mysterious until its assumed position in Amicactenus was corroborated by both morphological and molecular analyses, hence its name ‘ mysticus ’.

Diagnosis

Males of Amicactenus mysticus are recognized by the shape of the RTA ( Figs 8A, 9C View Figure 9 ) with a tiny tooth along the base of the ventral rim and by the deeply incised MA ( Figs 8B, 9A View Figure 9 ); epigyne ( Figs 8C, 10A – F) with large copulatory openings visible in the anterior part on either side of the MS.

Description

Male (holotype). Total length 20.6. Carapace 10.6 long and 8.5 wide. Clypeus 0.56 high. Eye diameters: AME 0.56, ALE 0.33, PME 0.56, PLE 0.49. Coloration ( Fig. 7A, B View Figure 7 ): carapace reddish brown with network of fine dark lines; chelicerae and sternum dark brown; legs uniform medium brown with longitudinal darker stripes; abdomen: dorsum dark grey with numerous long, dark, erect setae; in front with broad, short, lancet-shaped pale spot; venter dark grey with two rows of small apodemes. Chelicerae with three promarginal teeth, median larger; four retromarginal teeth, proximal distant from the remaining three, basal smallest; intermarginal denticles present. Leg measurements: I: femur 13.5/ patella 5.5/ tibia 10.2/ metatarsus 13.8/ tarsus 5.0/ total 48.0; II: 12.1/ 5.2/ 9.9/11.8/ 4.8/ 43.8; III: 10.9/ 4.1/ 9.2/ 10.9/ 4.8/ 39.9; IV: 13.5/ 4.5/ 12.3/ 15.6/ 5.0/ 50.9. Leg formula 4123. Leg spination: femur I pl1-1- 1-1 d1-1-1 rl1-1, II pl1-1-1 d1-1-1 rl1-1-1, III pl1-1-1- 1 d1-1-1 rl1-1-1, IV pl1-1-1-1 d1-1-1 rl1-1; patella I pl1 rl1, II pl1 rl1, III pl1 rl1, IV pl1 rl1; tibia I v2-2- 2-2-2 d1-1-1 rl1-1-1, II v2-2-2-2-2 d1-1-1 rl1-1-1, III v2-2-2 pl1-1-1 d1-1-1 rl1-1, IV v2-2-2 pl1-1 d1-1 rl1-1; metatarsus I v2-2-2 pl1-1-1, II v2-2-2 pl1-1-1, III 8 dispersed dw6, IV 8 dispersed dw4; Mt IV slightly modified: narrow, elongate, slightly flattened ventrally in the middle, without field of nodules. Palp ( Figs 8A, B, 9A – C View Figure 9 ): tibia curved outward, ventral projection on distal margin present, with three long spines; RTA near distal margin, conical, with small but conspicuous tooth on inferior margin cymbium slender, curved inward, densely hairy in distal half, with blunt, retrolateral proximal projection; MA deeply incised prolaterally; embolus with fairly broad base and sharp tip; conductor membranous, c-shaped.

Female paratype ( DNA-N 08, MRAC 238919). Total length 21.7. Carapace 9.7 long and 8.4 wide. Clypeus 0.59 high. Eye diameters: AME 0.53, ALE 0.36, PME 0.62, PLE 0.59. Coloration ( Fig. 7C, D View Figure 7 ): carapace uniform chestnut brown with faint pattern of darker stripes; chelicerae dark brown; sternum and legs uniform medium brown; abdomen: dorsum dark with broad median paler bar in anterior half; venter dark grey with two rows of small apodemes; paler in front of epigastric fold. Chelicerae with three promarginal teeth, median larger; four retromarginal teeth, proximal tooth distal from the remaining three, basal smallest; intermarginal denticles present. Leg measurements: 9.8/ patella 4.7/ tibia 9.7/ metatarsus 9.1/ tarsus 2.6/ total 35.9; II: 9.7/ 4.4/ 8.5/ 8.8/ 2.6/ 34.0; III: 8.2/ 3.3/ 6.2/ 7.5/ 2.4/ 27.6; IV: 9.9/ 3.8/ 8.5/ 12.2/ 3.3/ 37.7. Leg formula 4123. Leg spination: femur I pl1-1-1-1 d1-1-1 rl1-1, II pl1 d1-1-1, III pl1-1-1-1 d1- 1-1 rl1, IV 1-1-1 d1-1-1 rl1; patella none; tibia I v2-2- 2-2-2 pl1-1, II v2-2-2-2 pl1-1 rl1, III v2-2-2 pl1-1 d1- 1-1 rl1-1, IV v2-2-2 pl1-1 d1-1-1 rl1-1; metatarsus I v2-2-2, II v2-2-2, III v2-2-2 pl1-1 rl1-1, IV v2-2-2 pl1-1 d1-1; Mt IV unmodified. Epigyne ( Figs 8C, 10A – D): MS with clearly sclerotized rims; large copulatory opening in anterior half on either side of MS; posterior plate bulging, almost as large as MS, with setae; LP lost in this specimen ( Fig. 10C, D); flattened, roughly triangular with blunt tip in Pt ( Figs 8C, 10A, B). Vulva ( Fig. 10E, F) with large, oval spermathecae.

Remarks

Almost all females in our collections have the epigynes marked by what is apparently the result of copulation: one or both of the processes of the LS are missing, and the MS is damaged and ‘eroded’ along the sides; along these areas the MS is bordered by dark sclerotization which can only be explained as an effect of the healing process. In one female ( Figs 8C, 10A), one of the copulatory openings is blocked by a structure that is apparently an MA of the male palp. This is the first instance in spiders in which an MA is used as an epigynal plug. In combination with the broken LP, the presence of a plug might represent an efficient postcopulatory barrier. J ager € & Minn (2015: fig. 40) also reported a peculiar case of plugging in Ctenus natmataung J€ ager & Minn, 2015, in which the male uses a breakable tip of its RTA to block the entry of the epigyne.

Distribution

Known from Seringbara Forest on Mt. Nimba , Guinea and Bong Range Forest in Liberia.