Ptilototheca soutpansbergensis, Herbert, 2016

Herbert, David G., 2016, New narrow-range endemic land snails from the sky islands of northern South Africa (Gastropoda: Streptaxidae and Urocyclidae), European Journal of Taxonomy 236, pp. 1-29 : 10-15

Ptilototheca soutpansbergensis gen. et sp. nov.

urn:lsid:zoobank.org:act:F3F6A7DF-A655-483B-9865-AB0AA56DCCE8

Figs 4–8

Etymology

Named after the Soutpansberg massif, to which the species is endemic.

Material examined

Holotype

SOUTH AFRICA: Limpopo, Soutpansberg, Sibasa area, Phiphidi Falls , 22.9483° S, 30.3950° E, ~ 1000 m, indigenous forest, in leaf-litter, D. Herbert, 20 Nov. 1997, diameter 9.2 mm, height 6.1 mm ( NMSA V5567 /T4069, body in ethanol).

Paratypes (listed west to east)

SOUTH AFRICA: Limpopo, Soutpansberg, Hanglip Forest, picnic site, 22.99951° S, 29.88643° E, 1540m,northern mist-belt forest, in leaf-litter,leg.D.Herbert, L. Davis &M.Cole, stn 14-14, 29 Nov.2014 ( NMSA P0214/T4070, three specimens, body of one in ethanol); Hanglip Forest, 23.017° S, 29.900° E, indigenous forest, J. Swaye, Mar. 2001 ( NMSA V9485/T4071, five dry specimens; ELM D18041/T039, one dry specimen); Goedehoop Forest, 23.067° S, 30.121° E, 1250 m, sorted from leaf-litter, C. Symes, 30 Oct. 1999 ( NMSA V7506/T4066, six dry specimens); Entabeni Forest, 22.99092° S, 30.27829° E, Afromontane forest, in leaf-litter, J. Swaye, L91, L95, Oct.–Nov. 2001 ( NMSA W2259/T4067, nine dry specimens, seven in ethanol); Entabeni Forest, environs of Kliphuis, 22.98589° S, 30.28127° E, 1345 m, northern mist-belt forest, in leaf-litter, D. Herbert, L. Davis & M. Cole, stn 14-17, 30 Nov. 2014 ( NMSA P0183/T4068, 11 specimens, bodies of five in ethanol; NHMUK 20160040, one dry specimen; RMNH.5004144, one dry specimen); Entabeni Forest, environs of Kliphuis, 22.98455° S, 30.28272° E, 1365 m, northern mist-belt forest, in leaf-litter, D. Herbert, L. Davis & M. Cole, stn 14-16, 30 Nov. 2014 ( NMSA P0186/T4063, 10 specimens, bodies of five in ethanol); Thathe Vondo Forest, 22.87705° S, 30.35026° E, Afromontane forest, in leaf-litter, J. Swaye, L41, Oct.–Nov. 2001 ( NMSA W2080/T4064, 18 dry specimens, two in ethanol); Thathe Vondo Forest, near sacred shrine, 22.92649° S, 30.35270° E, 1075 m, northern mist-belt forest, in leaf-litter, D. Herbert, L. Davis & M. Cole, stn 14-18, 1 Dec. 2014 (P0225/T4065, one specimen, body in ethanol; ELM D18049/T040, one dry specimen); Thathe Vondo Forest, near sacred shrine, 22.92173° S, 30.35760° E, 1090 m, northern mist-belt forest, in leaf-litter, D. Herbert, L. Davis & M. Cole, stn 14-19, 1 Dec. 2014 ( NMSA P0304/T4060, two specimens, body of one in ethanol).

Other material (listed west to east, all in NMSA)

SOUTH AFRICA: Limpopo, Soutpansberg, Dundee Forest, 23.017° S, 29.515° E, 1525 m, sorted from leaf-litter, C. Symes, 24 Jul. 1999 (V7516); Hanglip Forest, 23.00002° S, 29.88789° E, 1360 m, mist-belt forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 16 Dec. 2006 (W5637); Hanglip Forest, 23.017° S, 29.900° E, 1370 m, A.C. & W.H. van Bruggen, Feb. 1965 (A8342); Entabeni Forest, 23.013° S, 30.080° E, 1175 m, sorted from leaf-litter, C. Symes, 16 Jul. 1999 (V7494); Goedehoop Forest, 23.07253° S, 30.11494° E, 1190 m, Afromontane forest, in leaf-litter, J. Swaye, L59, Oct.–Nov. 2001 (W2064); Entabeni Forest, 23.000° S, 30.233° E, indigenous forest, J. Swaye, L19a, Mar. 2001 (V9475); Entabeni, Matiwa Kop, 22.983° S, 30.250° E, 1310 m, in forest, A.C. & W.H. van Bruggen, Feb. 1965 (A8352); Entabeni Forest, 22.983° S, 30.250° E, 1160 m, A.C. & W.H. van Bruggen, Feb. 1965 (A8341); Entabeni Forest, 22.99541° S, 30.28023° E, Afromontane forest, in leaf-litter, J. Swaye, L30, Feb.–Mar. 2001 (W2261); Thathe Vondo Forest, 22.872933° S, 30.338783° E, 1280 m, indigenous Afromontane forest, in leaf-litter, J. Horn, 1 Mar. 2006 (W7717); Thathe Vondo Forest, 22.876° S, 30.349° E, 1430 m, indigenous forest, in leaf-litter, C. Symes, 4 Nov. 1999 (V7639).

Type locality

SOUTH AFRICA: Limpopo, Soutpansberg, Sibasa area, Phiphidi Falls, 22.9483° S, 30.3950° E, ~ 1000 m.

Identification

Easily identified on account of the fact that it is the only heliciform urocyclid occurring in the Soutpansberg that has a spirally punctate protoconch. Additional distinctive anatomical characters are given in the generic diagnosis above.

Description

SHELL ( Fig. 4 ). Small, globose-lenticular, largest specimen with diameter 10.0 mm, height 4.9 mm; H:D 0.62–0.71; periphery below mid-whorl, evenly rounded; suture indented, but not strongly so, inserting above periphery; very thin and delicate. Protoconch diameter 1.1–1.4 mm; junction with teleoconch weakly marked; nucleus more or less smooth, but protoconch thereafter with numerous microscopic punctations arranged in close-set spiral lines ( Fig. 4 E–F), also with some collabral alignment; in last quarter whorl punctations coalesce to form fine incised spiral lines. Teleoconch of up to 2.5 whorls; whorl expansion moderate; sculptured with fine, close-set, microscopic spiral striae, relatively weak on first whorl but strengthening and relatively distinct from start of second whorl onward; teleoconch otherwise only with weak, uneven growth irregularities. Columella concave, adapical region whitish and reflected over umbilical region and fused to adjacent part of base, forming a distinct umbilical channel; aperture obliquely lunate. Translucent, more or less uniformly yellowish-brown; apical and basal surfaces both glossy.

EXTERNAL FEATURES ( Fig. 5 ). Head and neck usually dark grey dorsally, pale greyish-white ventrally; grey pigmentation associated with skin granules and thus appearing as dense spotting; pigmentation weaker in some specimens; tentacles brownish-grey, yellowish-brown in pale individuals; posterior of foot more uniformly grey, caudal appendage somewhat darker. Body lobes of mantle edge grey; right and left shell lobes elongate-trigonal to spathulate when extended over shell, pale and translucent; posterior of foot and mantle lobes with scattered, minute, bluish-grey pigment granules. Pulmonary lining behind mantle edge variously bordered with cream and black pigmentation, often as collabral bands; additional dark blotches and lines posterior to this, with a very prominent and well-defined black band overlying primary ureter, to the right of pale tissues of kidney, sometimes with a further well-defined line of cream pigment to the right of (i.e., dorsal to) black band ( Fig. 5B ). Spire viscera dark brown with irregularly branching, cream venation, usually sparse and sometimes virtually absent. Caudal pit and appendage well developed.

RADULA ( Fig. 6 ). Formula R+9+(1–2)+(70–80); rachidian tricuspid, laterals essentially bicuspid with a mesocone and strong basal ectocone, but also with a minute endocone on side of mesocone; laterals followed by 1–2 intermediary teeth and then a long series of marginals; marginals curved and terminally bicuspid, but with a series of smaller cusps or serrations on concave outer edge, these proportionately stronger on smaller teeth toward radula margin.

DISTAL GENITALIA ( Fig. 7 ). Penis cylindrical, tapering toward apex, surrounded in a thin sheath, occasionally slightly kinked in mid region; penis divided into two portions, a thick muscular apical region (~¾ of penis length) ending at a conical penial verge, and a basal thinner-walled preputial region lined internally by coarse rounded papillae ( Fig. 7B ). Epiphallus extremely short, with a small caecum arising close to penis-epiphallus junction; retractor muscle attached to penis apex, close to base of caecum. Flagellum very short and squat, divided into F1 and F2, but not sharply so ( Fig. 7C ); F1 broad basally, twisted into approximately one revolution, internal diverticulae poorly delineated; F2 a small papilla-like structure at tip of F1, internal diverticulae more visible. Vas deferens long, thick and much convoluted in proximal portion between base of spermoviduct and penis base; inserts at junction of epiphallus and flagellum without evidence of chalky internal material. Genital atrium simple; vagina short; gametolytic sac capacious, its duct of moderate length; base of free oviduct somewhat swollen, pale apricot; spermoviduct divided into distinct prostatic and oviductal portions. Spermatophore elbowed ( Fig. 7D ), with a relatively slender capsule; most of tail with well-developed, fan-like spines with multiple branches (often in clumps), the tips finely pointed and recurved; tail initially relatively slender, but broader and more robust in mid-region; unbranched tip of tail very short.

Distribution ( Fig. 8 )

A narrow-range endemic, known only from the Soutpansberg massif, Limpopo, South Africa; at altitudes between 1000 and 1525 m above sea level.

Habitat

Northern mist-belt forest ( Mucina & Rutherford 2006); all material collected to date has been found in forest floor leaf-litter.

Figures

Fig. 4. Ptilototheca soutpansbergensis gen. et sp. nov. A–D. Holotype, diameter 9.2 mm (NMSA V5567/ T4069). E. Protoconch showing sculpture of punctate spiral lines, Entabeni Forest (paratype, NMSA P0186/T4063). F. SEM of protoconch microsculpture, Thathe Vondo Forest (paratype, NMSA W2080/ T4064). Scale bars: E = 0.5 mm; F = 250 µm.

Fig. 5. Ptilototheca soutpansbergensis gen. et sp. nov., living animals, Entabeni Forest, Soutpansberg, Limpopo. A. Darkly pigmented individual, shell diameter 8.4 mm (paratype, NMSA P0186/T4063). B. Paler individual showing contrasting pigmentation overlying the renal area, shell diameter 8.0 mm (paratype, NMSA P0183/T4068).

Fig. 6. Ptilototheca soutpansbergensis gen. et sp. nov., radula, holotype (NMSA V5567/T4069). A. Rachidian and left lateral teeth. B. Rachidian and innermost lateral teeth. C. Inner left marginal teeth. D. Outer left marginal teeth. Scale bars: A, C = 50 µm; B, D = 25 µm.

Fig. 7. Ptilototheca soutpansbergensis gen. et sp. nov., genitalia. A. Entire genital system. B. Basal portion of penis opened to show penial verge and coarsely papillate preputial region. C. Flagellum and epiphallus. D. Spermatophore. A–C. Paratype, NMSA P0304/T4060. D. Paratype, NMSA W2259/T4067.

Fig. 8. Map showing the distribution of new urocyclid species in relation to centres of plant endemism (Van Wyk & Smith 2001). Green circles = Ptilototheca soutpansbergensis gen. et sp. nov.; blue triangles = Sheldonia wolkbergensis sp. nov.; maroon squares = Sheldonia monsmaripi sp. nov.; pale blue = Soutpansberg Centre; pale orange = Wolkberg Centre (Serala Subcentre); pale green = Wolkberg Centre (Blyde Subcentre). Contours at 1000 and 2000 m.