Filopalpus kakaensis, Martens, 2022

Martens, Jochen, 2022, From the Ethiopian Bale Mountains hotspot-Filopalpinae subfam. nov., a new taxon of Laniatorean harvestmen based on external and genital morphology (Arachnida, Opiliones, Assamiidae), Zootaxa 5159 (2), pp. 221-244 : 229-231

Filopalpus kakaensis sp. nov.

( Figs 25–39 )

Type material: Holotype (CJM 8999), ♂, ETHIOPIA, Oromia, Mt. Kaka, E-slope above Meraro , 3370–3500 m, leg. 25.11.2017, 07°22’57”N, 39°11’27”E . Paratype (CJM 8968), ♀, ETHIOPIA, Oromia, Mt. Kaka , NE part of crater region, 3900–4100 m, leg. 29.11. – 1.12.2017 ; 07°23’N, 39°10’ E.

Diagnosis: Relatively large species, total body length 3.5, dorsal side of body with a dense layer of polygonal tubercles, not touching each other, male pedipalp femur slender, slightly as long as body length.

Etymology: It refers to the collecting site, Mt. Kaka in the Bale Mountain range; adjective mode.

Description: MALE. Body, dorsal side ( Figs 25–26 ): Relatively large species of the known species set. Scutum densely covered with marked polygonal blackish tubercles, nearly touching each other but slightly separated from each other indicated by light gaps; frontal rim of prosoma equipped with a row of 12 pointed apophyses of various sizes, larger ones on left and right half of distal rim; two relatively long pointed apophyses para-median on the scutal areas I–V; free tergites visible from above, each covered by a narrow row of slender, drawn-out pointed apophyses, longest ones in mid-part of tergites.

Tuber oculorum ( Figs 25 ): Small, front part close to the distal rim of prosomal scutum, irregularly equipped with long pointed blackish apophyses, central distal one longest, slightly surpassing distal rim of prosoma; yellow, small tubercles black.

Colour pattern ( Figs 25–26 ): Most tubercles brownish to blackish, small light yellow parts on prosoma and opisthosoma caused by uncolored tubercles.

Body, ventral side: Cx irregularly all over covered with relatively large apophyses of various form (not markedly polygonal), all pointed and with seta on top. Op gen light yellowish, all sternites brownish, with a row of short apophyses, longest on lateral sides, intersegmental membranes light.

Legs: All articles light brownish to blackish of normal size and proportions, no articles enlarged or inflated, Tr smooth except for few minute tubercles, all articles of all legs round in cross section, all articles irregularly covered with low tubercles, all pointed with small seta (except articles of Ta). Number of tarsomeres on legs I–IV: I 4, II 7, III 5, IV 6 (same numbers in female, see below; equal numbers on right and left leg).

Pedipalp ( Figs 25 , 35 ): Extremely long, thin and filiform, Tr ( Fig. 34 ) with one ve larger apophysis; Fe longer than entire body, all articles slenderer then those of legs I–IV; Pt slightly shorter than Fe; Fe and Pt slightly broadened towards distal end; Ti ( Figs 31, 33 ) extremely short, parallel-sided; Ta shortest article, similar to Ti but fusiform. All pedipalpal articles devoid of any strong and/or elevated tubercles, few fine light setae on all articles, elongated setae on Ta, length similar to depth of article.

Chelicera ( Figs 36–37 ): Basal article slender, dorsally strongly concave at mid portion, less so on ventral side, few strong tubercles dorso- and ventro-distally with minute seta on top, 2 nd article slightly inflated, fusiform, frontally with a dense cover of fine tubercles, single strong setae frontally and distally close to insertion of 3 rd article, a strong but slender Apo near mid-half on pro-lateral side close to frontal side of the base of fixed digit (2 nd article).

Penis morphology ( Figs 29–32 ): Truncus penis slender (la and do/ve views, Figs 29–30 ), from the small slightly enlarged base in proximal third nearly parallel-sided, then continuously enlarged towards distal end (la view). Truncus in do/ve view in distal section with markedly enlarged frontal rim divided in two rounded lobes with slight median crevice. Glans a longish tube, emerging from dorso-distal enlarged part of truncus, slightly surpassing distal end of truncus in everted state ( Figs 31–32 ), stylus and ventral lamella situated close to each other ( Fig. 32 ); glans tube with a dense inner cover of minute stings, their tips directed to distal opening, but reverse when prickly funnel expanded; in everted state stylus projecting the expanded prickly funnel. Truncus equipped with only two stout sensilla close to insertion of glans tube.

Description: FEMALE. Characters of external morphology generally like in male including coloration and equipment of body with tubercles and apophyses though less intensively developed ( Figs 27–28 ).

Chelicera ( Figs 38–39 ): Generally smaller than male, 2 nd article shorter and slenderer, proximal article distally less inflated. Equipment with apophyses similar to male, but lacking the conical apophysis close to the basis of the fixed digit ( Fig. 39 ).

Pedipalp ( Figs 27 , 33 ): Extremely short (total length about body length), Ti and Ta of about equal length, slightly shorter than Fe; Tr with two ve apophyses of different sizes with strong seta on top; Fe smooth, nearly parallel-sided, slightly enlarged distally, dorsally with few low apophyses and three larger ones ventrally in proximal half, all with seta on top; Pt slightly curved to ventral side and slightly enlarged distally, one ventro-distal apophysis; Ti equipped with three elevated tubercles of different sizes ventrally, the central one largest with a long immovable seta on top; Ta with several indistinct and low seta-topped apophyses ventrally and few small additional setae interspersed, few on do side; claw strong, length slightly less than Ta length.

Measurements (male, female in parentheses):

Body length: Including pointed apophysis on distal and proximal rim of scutum 3.0 (3.5), without apophyses, including free tergites: 2.8 (3.4).

Leg II: Tr 0.3 (0.3), Fe 2.1 (1.8), Pt 0.5 (0.5), Ti 1.8 (1.5), Mt 1.3 (1.3), Ta 1.4 (1.4); total: 7.4 (6.8).

Pedipalp: Tr 0.3 (0.3), Fe 2.8 (0.8), Pt 2.7 (0.5), Ti 0.7 (0.4), Ta 0.45 (0.4), claw 0.4 (0.4); total: 7.35 (2.8). Male pedipalp: 2.63 times longer than female pedipalp.

Number of tarsomeres of legs I–IV (right and left leg): I 4/4 (4/4), II 7/7 (6/7), III 5/5 (5/5), IV 6/6 (6/6).

Penis length: 1.15.

Relationships: F. kakaensis sp. nov. is most similar to F. joschmidti sp. nov., which is smaller, has a different genital morphology (concavity on penis ventro-distal plate) and all tubercles of ventral and dorsal side are distally rounded, stump. Pedipalpal proportions are similar in both species, also the lack of elevated tubercles on all pedipalp articles. But in F. kakaensis sp. nov. pedipalp is shorter. The elevation of the collecting localities of both species are separated by about slightly more than 1.000 m.

Distribution, habitat, phenology: Until now only the type and the paratype specimens are known from above Meraro on the eastern slope and from the northeastern part of the crater region of Mount Kaka, a subsidiary shield volcano of Bale Mountains. The two collecting localities are situated at altitudes of 3370–3500 m a.s.l. and 3900– 4100 m a.s.l., the latter in the afro-alpine zone. The lower collecting locality is situated in the (originally) highmontane forest belt of Mount Kaka; to be expected in the former place is a forest formation dominated by the African Redwood ( Hagenia abyssinica , Rosaceae ) in transition to Erica arborea (Ericaceae) forest. But Mount Kaka is completely deforested and hardly any original forest patch is left. Litter and raw humus was sieved; at the lower locality earth was dug along a stream in a steep canyon. Only there were bushes left which are unavailable for cattle and man-made fire.

Figures

FIGURES 25–28. Filopalpus kakaensis sp. nov. Male holotype (25–26); female paratype (27–28). Body lateral view (25, 27) and dorsal view (26, 28), Scale: 1 mm.

FIGURES 29–39. Filopalpus kakaensis sp. nov. Male holotype (29–32, 34–37) and female paratype (33, 38–39). 29–30. Penis, dorsal and lateral view. 31–32. Glans dorsal and lateral view. 33. Pedipalp retro-lateral view. 34. Pedipalpal trochanter and base of femur. 35. Pedipalpal tibia and tarsus, retro-lateral view. 36–39. Chelicera retro-lateral (36, 38) and pro-lateral view (37–39). Scales: 29–39: 0.3 mm.