Spinibdella polyattenuata, Theron, Elizabeth Omukunda Pieter D & Ueckermann, E A, 2012

Theron, Elizabeth Omukunda Pieter D & Ueckermann, E A, 2012, Spinibdella Thor (Acari: Bdellidae) from southern Africa: descriptions of five new species and the redescription of S. thori (Meyer & Ryke), Zootaxa 3304, pp. 1-24 : 6-8

Spinibdella polyattenuata sp. nov. Omukunda, Theron & Ueckermann

( Figs 11–19 )

Description. Female (n=3). Dimensions: length including gnathosoma 761–893 (827); width 353–415 (384); length of gnathosoma 191–220 (205); length of chelicerae 172–191 (182); DHS 15–19 (17); length of palp segments: I 10–13 (12); II + III 105–113 (109); IV 19; V 36 –42 (39); des 138–145 (142); ves 99; length of legs: I 406–422 (414); II 359–376 (368); III 403–430 (417); IV 443–514 (479); length of setae: vi 114 –109 (112); ve 23–25 (24); sci 119–129 (124); sce 56 – 60 (58); c1 37–40 (39); c2 39–42 (42); d 38–44 (38); e 39–44 (42); f1 47 – 48 (48); f2 44–46 (44); h1 42–56 (49); h2 40–60 (51)); distance: vi– vi 59–63 (58); first interspace (c1 to d) 86–92 (90).

Gnathosoma ( Figs 11–13 ). Chelicerae with fine continuous longitudinal striations, each with a pair of strong dorsal setae inserted as shown on figure 11. Chelae are short and thick, movable digit slightly curved. Fixed digit straight and slightly shorter than movable digit. Palp ( Fig. 12 ) almost as long as hypostome. Length of tibiotarsus about twice that of genu. Palp chaetotaxy: from trochanter to tibiotarsus; 0-8-1-4-4 sts, 1 ω, 1 des, 1 ves. Hypostome has two pairs of strong ventral setae inserted as shown in figure 13 and one pair of dorsal setae (DHS). Anterior region has fine continuous longitudinal striations, but transversely striated basally. Two pairs of adoral setae are present.

Dorsum ( Figs 14–15 ). Next to naso are two conspicuous tracheal openings, external verticals nude, relatively thin and short, situated in the posterior half of prodorsum; internal scapulars modified to trichobothria and external scapulars thick, long and finely pilose. Centre of prodorsum with fine broken transverse striations. One pair of detectable eyes and posterior region marked with characteristic striation pattern ( Fig. 14 ). Beneath cuticle in same position is a raised region resembling the eye, but not differentiated. Median eye not detectable in this species. Except vi, ve and sci, the remaining dorsal setae are pilose. Setae c1 less than ½ first interspace. Striation pattern finely broken as shown on figure 15. Sejugal groove conspicuous

Venter ( Fig. 16 ). Thirty–four aggenital setae finely pilose, anterior pair between coxae IV, two unpaired setae posterior to second pair. Nine or 10 pairs of thick, short attenuate genital setae linearly arranged on genital plates. Two pairs of small genital discs occur in posterior half and third in anterior half. Genital tracheae conspicuous. Ovipositor has 12 subapical and six medial setae. Anal valves terminal and bordered by one pair of ad1, ad2, ad3, an1, an2, ps2, and ps3 setae. Setae ad3 very small. Striae bordering valves parallel as shown in figure 16.

Legs ( Figs 17–18 ). Legs shorter than idiosoma. All femora divided; tactile setae on coxae are finely pilose; setae on trochanters may be nude or pilose; other segments may have both pilose and nude or either setae. All genua have duplex setae in proximal half, genua I has 13 attenuate solenidia while rest have three. This species is unique in that genu IV also has duplex setae. Tibiae I have a very long attenuate blunt solenidion ( Fig. 17 ), a trichobothrium and many attenuate solenidia (13); tibiae II have a reduced blunt and one attenuate solenidia; tibiae III have 1 attenuate solenidion and tibiae IV with a trichobothrium. Tarsi I–IV apparently with about three pairs of serrated setae distally. Tarsi I have two long attenuate blunt solenidia, three attenuate solenidia and a peg. Tarsi II have two long blunt solenidia ( Fig. 18 ) and a simple peg. Tarsus III with a proximal trichobothrium. Tarsus IV with a proximal attenuate solenidion, a trichobothrium. Claws longer than pretarsus and have two rows of rays, outer row with four strong rays, inner with numerous weaker rays. All coxal setae are pilose; other segments may have both simple and pilose setae. Leg chaetotaxy as follows: coxae I–IV 6-7 -7-5 sts (pilose); trochanters I–IV 1-1 -2-1 sts; basifemora I–IV 9-9 -6-3 sts; telofemora I–IV 8-8 (7)-9-6 sts; genua I–IV 7 sts 1 duplex, 12 σ – 7 sts; 1 duplex, 2 σ – 8 sts; 1 duplex, 2 σ – 7 sts; 1 duplex, 2 σ; tibiae I–IV 14 sts, 13φ, 1tr, 1ĸ – 15(14) sts, 1 φ, 1 recessed blunt ϕ – 14 sts, 1 φ– 14 sts, 1tr, tarsi I–IV 26 sts, 5 ω, 1 ĸ – 26 sts, 2 ω, 1 ĸ – 23(24) sts, 1tr – 23 sts, 1 ω, 1tr.

Male ( Fig. 19 ). Dimensions: Length including gnathosoma 848; width 363; length of gnathosoma 197; length of chelicerae 178; length of palp segments: I 10; II + III 101; IV 19; V 38; des 133; ves 96; length of legs: I 405; II 346; III 405; IV 483; length of setae: DHS 19; vi 111; ve 18; sci 117; sce 54; c1 44; c2 46; d 39; e 43; f1 50; f2 46; h1 35; h2 29; distance: vi– vi 55; first interspace (c1 to d) 84.

Male small in size and genital region ( Fig. 19 ) and leg chaetotaxy differs from that of female. There are 42 fine pilose aggenital setae, anterior one unpaired seta between coxae IV, 14 pairs of attenuate genital setae present, arranged linearly in posterior half in one row with two rows in anterior half. Leg chaetotaxy as follows: coxae I–IV 6-5 -6-5 (pilose) sts; trochanters I–IV 1-1 -2-1 sts; basifemora I–IV 10-10-7 -3 sts; telofemora I–IV 9-9 -8-6 sts; genua I–IV same as female; tibiae I–IV 13 sts, 12φ, 1tr, 1ĸ-16 sts, 1 recessed blunt ϕ – 14(15) sts, 1 φ - 13 sts, 1tr; tarsi I–IV as female.

Type material. SOUTH AFRICA, Eastern Cape Province: Holotype female, 2 females and 2 males paratype, from rocks in between supralittoral and littoral zone, Schoenmakerskop, 3 July 1994, Coll. M. Marshall.

Etymology. Poly is the Greek word for many and attenuatus Latin word for thin and tapered, thus referring to many attenuate solenidia on tibiae and genua I in this species.

Differential diagnosis. This species closely resembles S. trinomma by the presence of one pair of eyes, but can easily be differentiated by: absence of anterior median eye; two clear tracheal openings on naso; 13 attenuate solenidia on genu I; three attenuate solenidia on genua II–IV; duplex setae on genua IV; 13 attenuate solenidia on tibia I and a very long attenuate blunt solenidion on same segment. It is a remarkable species with a striation pattern different from other Spinibdella species (dorsum and venter finely broken). The chelae are strong, relatively short and curved. This species has the highest number of attenuate solenidia in this genus.

Figures

FIGURES 11 – 16. Spinibdella polyattenuata sp. n.: 11. Female chelicera; 12. Female palp; 13. Female hypostome; 14. Female prodorsum; 15. Female dorsal view; 16. Female ventral view.

FIGURES 17 – 19. Spinibdella polyattenuata sp. n.: 17. Female leg I; 18. Female leg II; 19. Male genitalia.