Friday, May 25, 2018

[Arachnida • 2018] Charinus kakum • A New Species of Charinus (Amblypygi: Charinidae) from Ghana, with Notes on West African Whip Spiders

Charinus kakum  Harms, 2018

The fauna of whip spiders (Amblypygi) in Western Africa is poorly known but probably diverse. Here, I describe the new species Charinus kakum sp. n. based on female morphology, and accompanied by DNA sequence data. The species is small and differs from other African species of Charinus in the low number of pseudosegments on leg IV, female genital features, spination patterns of the pedipalp, and small body size. It was collected from wet tropical rainforest in Kakum National Park, Ghana and is only the fourth species of Charinus to be recorded from the highly diverse Western African biodiversity hotspot. With a total body length of not even 6 mm it is also one of the smallest whip spiders in the world.

Key Words: Amblypygid, Arachnida, Kakum National Park, new species, taxonomy

Figure 2. Female holotype of Charinus kakum sp. n.: A, habitus dorsal; B, genital operculum in ventral view. Arrow indicates the position of the ventral sac covers; C, opisthosoma in dorsal view; D, eggs carried by the female (removed from the genital operculum for imaging).

 Figure 3. Female holotype of Charinus kakum sp. n.: A, details of habitus in dorsal view; B, details of habitus in ventral view; C, carapace in dorsal view; D, prosomal sternites in ventral view.

Charinidae Quintero, 1986
Charinus Simon, 1892

Type species: Phrynus australianus L. Koch, 1867, by original designation.

Taxonomic remarks: Weygoldt (2000a) defined Charinus based on the armature of the pedipalp: with three large dorsal spines on the tibia of which the first one is the largest and the others decrease proximally in length; spine 1 sometimes followed distally by one to three spinelets, pedipalp basitarsus with two spines of which the distal spine is largest. Charinus also differs from the closely related Sarax in lacking ventral sac covers (Rahmadi and Kojima 2010). The genus currently includes more than 70 species (Vasconcelos and Ferreira 2017) but is in need of revision (Weygoldt 2000a, b). Nonetheless, the new species aligns well with the current genus diagnosis and is placed here until such revision has been carried out.

Charinus kakum sp. n.

Diagnosis: Charinus kakum sp. n. differs from the cave-inhabiting species C. milloti Fage, 1939 and C. fagei Weygoldt, 1972 in low number of tibial segments on leg IV (5 in C. millotei and C. fagei vs. 3 in C. kakum), trichobothria patterns of leg IV (compare with Weygoldt 1972, 2000a), small body size (prosoma length 2.6 in C. kakum), and shorter legs; from the island species C. africanus Hansen 1921 through the female genital operculum which has a steep ventral flexure at about two third of its length in C. africanus (Weygoldt 1972; Miranda et al. 2016b) but is uniform in C. kakum, and body size (ca. 8.0–8.5 mm in C. africanus and 5.8 in C. kakum; Hansen 1921).


Etymology: The specific epithet refers to the type locality, Kakum National Park in Ghana.

Distribution: Only known from the type locality by a single female individual. The wider distribution remains unknown and unfortunately no other specimens could be collected, despite targeted searches in the vicinity of the type locality.

 Danilo Harms. 2018. A New Species of Charinus (Amblypygi: Charinidae) from Ghana, with Notes on West African Whip Spiders.  Evolutionary Systematics. 2: 45-53.  DOI: 10.3897/evolsyst.2.24505