Allokoenenia afra Silvestri, 1913

Souza, Maysa Fernanda Villela Rezende & Ferreira, Rodrigo Lopes, 2022, Two extraordinary troglobitic species of Allokoenenia (Eukoeneniidae: Palpigradi) from Brazil: first records of this initially monotypic genus more than a century after its description, European Journal of Taxonomy 789, pp. 11-48 : 14-17

Allokoenenia afra Silvestri, 1913

Figs 1–2

Material examined

Typus (♀) and cotypus (immature)

GUINEA • Mamou .

Description

MEASUREMENTS AND RATIO. See Tables 1–2.

ADULT FEMALE (“ typus ”). Relative width of opisthosomal segments VIII–XI as described in the diagnosis of the genus by Rowland & Sissom (1980) ( Fig. 1A ); last opisthosomal segment with dorsal row of 2 +2 setae inserted around its half and two pairs of ventral setae, one inserted around middle of segment and other inserted in its distal half ( Fig. 2 ); flagellum formed by 14 short and rounded segments ( Fig. 1A– B ), each with whorl of setae of similar shape (at least one setae smaller than others in each segment); flagellar segments 1–3, 5, 7 and 9 with apical cuticular spines.

IMMATURE SPECIMEN (“cotypus”). Frontal organ formed by two branches distally pointed and basally expanded, with fine reticulation ( Fig. 1C ); cheliceral fingers with 8 teeth each; 6 setae (grt, r, gla, esp and 2 esd) on basitarsus of leg IV; relative width of last opisthosomal segments and chaetotaxy of segment XI as in adult.

Remarks

As previously mentioned, the poor condition of the type material allowed us to observe and describe only a small number of morphological features. From the simple and short description of the female adult of this species provided by Silvestri (1913), which includes a few drawings, it is possible to recognize the following additional characters: lateral organ with a single blade, deutotritosternum with a single seta, and opisthosomal sternites IV–VI with three pairs of a setae flanked by one s seta on each side (1 s +3 a +3 a +1 s). The author also described and illustrated the chaetotaxy of the genital lobes (10 +10 and 2+2 setae on first and second lobes respectively), and illustrated the articles of the palp, leg I and leg IV. However, it is not clear whether he represented the complete chaetotaxy of these body parts. According to the drawing of the opisthosoma presented by Silvestri (1913: 217, fig. VII, 2), the immature already has the primordia of genital lobes, but it was not possible to confirm whether it is a male or a female juvenile.

Due to the poor preservation of the type specimens, the collection of new specimens from the type locality is essential for its redescription according to the modern taxonomy of Palpigradi , thus allowing a more detailed comparison with the congeneric species.

Figures

Fig. 1. Allokoenenia afra Silvestri, 1913. A. Opisthosomal segments VIII–XI and first flagellar segment, ♀, typus. B. Flagellum (second to fourteenth flagellar segments), ♀, typus. C. Frontal organ, immature, cotypus. Scale bars: A–B = 100 μm; C = 10 μm.

Fig. 2. Allokoenenia afra Silvestri, 1913, immature, cotypus, ventral view of opisthosomal segment XI (the insertions of the dorsal setae are represented in dashed line). Scale bar = 40 μm.