Kerkophorus vittarubra, Herbert, 2017

Herbert, David G., 2017, A new genus and eight new species of tail-wagger snails from eastern South Africa, with a key to genera within Sheldonia s. l. (Gastropoda: Urocyclidae), European Journal of Taxonomy 309, pp. 1-50 : 11-17

Kerkophorus vittarubra sp. nov.

urn:lsid:zoobank.org:act:B8D472B5-F565-47B1-B8D2-FDACFD810B3F

Figs 6–10

Sheldonia inuncta (non Melvill & Ponsonby, 1899) – Connolly 1939: 145 (in part). — Herbert & Kilburn 2004: 264 (in part), un-numbered figure.

Diagnosis

Shell characterised by its large size, weakly angled periphery, elevated spire, silky surface, narrow redbrown peripheral line slightly above mid-whorl and large protoconch. Genital atrium large, containing a well-developed stimulator.

Etymology

From the Latin ‘ vitta ’, f., ribbon and the Latin ‘ ruber, rubra ’, red; referring to the infernal bureaucratic red tape now bedevilling scientific endeavour (and the red-brown peripheral spiral line on the shell). Noun in apposition.

Material examined

Holotype

SOUTH AFRICA: KwaZulu-Natal, Maphelane , 28.4050° S, 32.4217° E, 0–60 m, dune forest, on understorey vegetation, D. Plisko leg., May 1997 ( NMSA P0353/T4061 , dry shell with body in ethanol). Paratypes (listed north to south, all KwaZulu-Natal)

SOUTH AFRICA: Greater St Lucia Wetland Park, Manzimbomvu-Ozabeni area, 27.6167° S, 32.5500° E, woodland, under leaves, G. Davies leg., 28 May 2006 ( NMSA W4283/T4042, one dry shell with body in ethanol); Cape Vidal, 28.128° S, 32.550° E, dune forest, P. Reavell leg., 1 Dec. 1978 ( NMSA W2277/ T4047, four dry shells); same data as holotype ( NHMUK 20160241, one dry shell; NMSA V4725/T4062, six dry shells with bodies in ethanol; RMNH.5004184, one dry shell); Maphelane, forest between dunes and Umfolozi swamp, 28.407° S, 32.418° E, 0–15 m, on vegetation, abundant, D. Herbert leg., 30 Nov. 1995 ( NMSA V 2194 /T4044, 51 dry shells with 46 bodies in ethanol); Ongoye Forest, 28.830767° S, 31.736298° E, 307 m, M. and K. Cole and G. Williams-Wynn leg., 11 Apr. 2015 ( ELM W3904/T155, one dry shell with body in ethanol); Ongoye Forest, 28.83617° S, 31.71252° E, 327 m, on understorey trees and bushes, C. Stoffels leg., 9 Jan. 2014 ( NMSA W9692/T4046, seven dry shells with bodies in ethanol, plus one whole specimen in ethanol); Eshowe, 28.885° S, 31.468° E, 500 m, Falcon collection ( NMSA A8166/T4043, 37 dry shells with 11 bodies in ethanol); Eshowe, Dlinza Forest, 28.893419° S, 31.451602° E, on Dracaena leaf, M. Cole leg., 13 Jan. 2010 ( ELM W3447/T154, one dry shell with body in ethanol); Eshowe, Dlinza Forest, 28.90° S, 31.45° E, 500 m, scarp forest, on Tabernaemontana leaf, D. Eckard leg., 4 Sep. 1997 ( NMSA V5270/T4045, three dry shells).

Other material (listed north to south, all KwaZulu-Natal, NMSA)

SOUTH AFRICA: St Lucia, Eastern Shores, 28.175° S, 32.500° E, swamp forest, on Barringtonia racemosa leaves, P. Reavell leg., 5 Jan. 1990 (S869); Greater St Lucia, near St Lucia River mouth, 28.38213° S, 32.41981° E, dune forest, attached to understorey vegetation, A. Moussalli and D. Stuart- Fox leg., 17 Dec. 2003 (W4301); St Lucia Village, forest walk, coastal lowland forest, on low vegetation, D. Herbert leg., 19 Oct. 1997 (V5380); Maphelane, 28.4033° S, 32.2034° E, dune forest, H. van der Bank et al. leg., 17 Oct. 2011 (W8617) ( CO 1 barcode vouchers, BIN ABW7223); Maphelane, 28.4050° S, 32.4217° E, dune forest, R. Kilburn leg., 11 Jan. 1983 (B6045), O. Bourquin leg., 15 Jul. 1981 (B6046, V7216), S. Mclean leg., 16 Jul. 1987 (E1100), R. Kilburn, D. Herbert and R. Fregona leg., 10 May 1987 (E382), D. Morgan leg., 16 Feb. 1991 (S3401), D. Herbert leg., 30 Dec. 1995 (V2274), D. Plisko leg., 1 May 1997 (V5017); Maphelane area, 28.51162° S, 32.39775° E, on road to lighthouse, R. Kilburn, D. Herbert and R. Fregona leg., 13 May 1987 (E360); Enseleni Nature Reserve, 28.64410° S, 31.96180° E, coastal forest, on understorey vegetation, A. Moussalli and D. Stuart-Fox leg., 11 Nov. 2006 (W4705); Enseleni Nature Reserve, 28.6917° S, 32.0070° E, coastal forest, crawling over leaf-litter, D. Herbert leg., 13 Apr. 1997 (V4803); Enseleni Nature Reserve, 28.6917° S, 32.0070° E, in Barringtonia forest beside lake, D. Herbert leg., 15 Jan. 1995 (V656); Richards Bay area, S of Nhlabane River, 28.717° S, 32.170° E, at base of dunes, G. Anderson leg., 20 May 1996 (V3929); Empangeni, 12 km N of Mdibi swamp forest, 28.7519° S, 32.0794° E, on leaves, P. Reavell leg., 1 Mar. 1998 (V6526); Ongoye Forest, 28.808° S, 31.717° E, 350 m, under log on forest floor, D. Herbert leg., 18 Sep. 1999 (V7387); Ongoye Forest, 28.833° S, 31.717° E, 350 m, scarp forest, crawling over leaf-litter, D. Herbert leg., 6 Sep. 1997 (V5118); Ongoye Forest, 28.8417° S, 31.6870° E, 410 m, scarp forest dominated by Millettia and Drypetes , on leaves of understorey saplings, M.J. Lawes leg., 30 May 1999 (V7403); Ongoye Forest, west-central portion, 28.8417° S, 31.6888° E, scarp forest, in leaf-litter, G. Davies leg., 27 Jul. 2002 (W221); Ongoye Forest, 28.8417° S, 31.6870° E, scarp forest, on understorey foliage, A. Moussalli and D. Stuart-Fox leg., 22 Dec. 2003 (W3314, W4966); Ongoye Forest, 28.850° S, 31.733° E, 250 m, scarp forest, J. Londt leg., 29 Jan. 1988 (V6677); Eshowe, Dlinza Forest, 28.892° S, 31.450° E, 500 m, scarp forest, abundant on low vegetation, R. Miller leg., 1 Jan. 1996 (V2895); Eshowe, Dlinza Forest, 28.89743° S, 31.45711° E, indigenous forest, on understorey foliage, D. Stuart-Fox leg., 25 Mar. 2004 (W3320; W3222); Eshowe, Dlinza Forest, near ‘Oval’, 28.90° S, 31.45° E, 500 m, scarp forest, D. Eckard leg., 25 Jul. 1996 (V4020), on Tabernaemontana, D. Eckard leg., 5 Mar. 1996 (V4018), on fronds of fan palm in forest swamps, D. Eckard leg., 13 Jan. 1997 (V4528), on Dracaena leaf, D. Eckard leg., 4 Sep. 1997 (V5267), on Allophylus leaf, D. Eckard leg., 4 Sep. 1997 (V5268); Eshowe, Dlinza Forest, near twinspot hide, 28.90° S, 31.45° E, scarp forest, D. Eckard leg., 25 Jul. 1996 (V4019).

Literature record

SOUTH AFRICA: Kwazulu-Natal, Umbonambi (Kwambonambi) ( Connolly 1939: 145).

Potentially hybrid material of Kerkophorus piperatus sp. nov. × vittarubra sp. nov.

SOUTH AFRICA: KwaZulu-Natal: Nkandla Forest, 28.72239° S, 31.12373° E, mistbelt forest, on understorey foliage, A. Moussalli and D. Stuart-Fox leg., 3 Jan. 2004 (NMSA W3311); Nkandla Forest, Chibini area, 28.7227° S, 31.1282° E, 1200 m, mistbelt forest, under logs and in leaf-litter, D. Herbert, M. Bursey and T. Nangammbi leg., 20 Oct. 2003 (NMSA W1116; ELM D13805); Nkandla Forest, 28.740° S, 31.125° E, 1000–1100 m, mistbelt Podocarpus forest, A.C. and W.H. van Bruggen leg., 17 Jan. 1964 (NMSA V6960); Nkandla Forest, Mdonini area, 28.74531° S, 31.13567° E, 1050 m, mistbelt forest, under logs and in leaf-litter, D. Herbert, M. Bursey and T. Nangammbi leg., 21 Oct. 2003 (NMSA W1184); Nkandla Forest, 28.733° S, 31.117° E (NMSA A8167).

Description

SHELL ( Fig. 7 ). Lenticular to globose-lenticular, spire remaining relatively prominent; periphery at midwhorl, weakly angled in adults, more strongly so in juveniles; H:D 0.61–0.70 (N=25); suture shallowly indented, inserting at or slightly above periphery; thin, translucent, milky-white to pale buff, with a thin red-brown line just above periphery; surface silky, with little lustre. Protoconch large, diameter 2.2– 2.7 mm (N=20); junction with teleoconch weakly marked; essentially smooth, but bearing faint, closeset, microspiral sculpture. Teleoconch of up to 3.5 whorls; coiling relatively tight, whorls not expanding rapidly; sculptured by weak growth-lines and exceptionally fine and close-set, microscopic spiral lines resembling those on protoconch; later whorls also with microscopic axial sculpture of a similar nature, giving surface its lustreless sheen. Umbilicus narrow, mostly obscured by reflected upper portion of columella lip. Aperture roundly and obliquely lunate. Diameter up to 26.3 mm; holotype, diameter 24.8 mm, height 16.4 mm; specimens from inland localities smaller than those from coastal lowland and dune forest (diameter usually less than 20 mm).

LIVING ANIMAL ( Fig. 8 ). Head-foot greyish-white to greyish-brown, with minute cream-white pigment granules; dorsal neck and tail regions sometimes slightly darker; tentacles and optic retractor muscles usually darker grey; coloration of body lobes of mantle similar to head-foot; shell lobes slender and elongate; caudal appendage dark grey to black. Lining of pulmonary cavity weakly speckled with irregular black markings (less obvious in specimens from dune forest) and scattered cream spots, usually more dense beneath peripheral red-brown line of shell; pulmonary venation often conspicuous. Spire viscera brown with irregular cream markings and reticulate threads, more dense in inland specimens.

RADULA ( Fig. 9 ). Formula R+(18–20)+(1–2)+(100–110); rachidian tricuspid, anterior margin of shaft base poorly defined; 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 teeth of intermediate shape and then a very long series of marginals; marginals curved with a large terminal cusp and a weak subterminal one on outer (concave) margin; shaft lacking serrations; marginals progressively decreasing in size toward edge of radula, but otherwise morphologically similar.

DISTAL GENITALIA ( Fig. 10 A–B). Penis tightly looped inside a short sheath situated on top of enlarged genital atrium; penis divided into two portions separated by a constriction in mid-region; lumen wall

of apical half with longitudinal folds, that of lower portion with close-set micropapillae; no penis papilla or verge evident at constriction. Epiphallus short; caecum well developed, more or less equal to epiphallus in length, somewhat curved, distal portion broader with bluntly rounded apex, not internally compartmentalised in this region; lumen wall with two raised longitudinal ridges and additional fine folds; caecum arising very close to penis apex and retractor muscle; epiphallus, caecum and penis apex forming a triple junction. Basal part of flagellum (f1) comprising ± 1 whorl, with distinct transverse internal structure; f2 slender, considerably longer than f1, variously curved but not convoluted; some evidence of chalky material inside proximal epiphallus; vas deferens slender and relatively short. Genital atrium greatly enlarged above lateral insertion of vagina; apical region containing a long, welldeveloped stimulator; lining of basal portion of atrium with low folds and a raised longitudinal pilaster running to base of stimulator; vagina short; gametolytic sac thin-walled and ovate to pyriform, often narrowing apically, gametolytic duct of moderate length; base of free oviduct swollen, dark charcoalgrey to black in fresh specimens; spermoviduct divided into distinct prostatic and oviductal portions.

SPERMATOPHORE ( Fig. 10C ). Elbowed, with a cylindrical capsule (length approx. 5.3 mm) and a long coiled tail; proximal part of tail smooth, followed by two rows of stout branching spines spiralling around tail; primary row extending for ± 1.25 coils; spines in mid-region larger and more complexly branched; a shorter, secondary row of approx. 10 spines on opposite side of proximal part of spinose region, these initially similar to those of primary row, but distal 4–5 smaller and with fewer branches; spines of primary row flabellate, terminating in stout, V-shaped bifurcations, the tips pointed and somewhat curved; distal third of tail lacking spines, very slender and variously curved or coiled.

Distribution ( Fig. 6 )

Endemic to the coastal region of northern KwaZulu-Natal, from Eshowe to just south of Sodwana Bay; at altitudes between sea-level and 500 m.

Habitat

Scarp Forest and Northern Coastal Forest ( Mucina & Rutherford 2006); living on leaves of understorey vegetation, sometimes abundant.

Remarks

Typical specimens of Kerkophorus vittarubra sp. nov. from coastal forests in the St Lucia area are relatively distinctive on account of their large, pale, silky textured shells with a narrow brown peripheral spiral line, and the rather limited dark speckling of the pulmonary lining. However, specimens from inland localities (e.g., Dlinza, Enseleni and Ongoye forests) are somewhat smaller (diameter <20 mm), of a more brownish colour and may exhibit some dark speckling of the pulmonary lining. These can be confused with K. piperatus sp. nov. (above), but in that species the shell has a more rounded periphery, the brown spiral line and suture are situated well above mid-whorl and the protoconch is not so large (1.65–1.90 mm vs 2.2–2.7 mm). The pigmentation of the pulmonary lining of K. piperatus sp. nov. is also darker and more dense. Further differences are evident in the distal genitalia and behaviour, specifically the genital atrium of K. piperatus sp. nov. is not enlarged and lacks a stimulator, whereas its epiphallic caecum is proportionately longer in relation to the epiphallus than is that of K. vittarubra sp. nov. In terms of behaviour, K. piperatus sp. nov. is primarily an inhabitant of the forest floor, whereas K. vittarubra sp. nov. lives mostly on the leaves of understorey vegetation during the wet season, retreating to the leaf-litter only to aestivate during the dry winter months. Over-wintering animals are of intermediate size (shell diameter 17–18 mm), suggesting that the life cycle extends over two wet seasons. The distribution data available thus far indicate that the two species do not co-occur.

The above notwithstanding, material collected in Nkandla Forest appears to be intermediate. The shell shape and coloration ( Fig. 2H ), and body colour are close to those of K. piperatus sp. nov., yet the genital atrium is enlarged and contains a stimulator. The possibility exists that this is a hybrid population.

To date this species has been identified with Kerkophorus inunctus ( Connolly 1939; Herbert & Kilburn 2004). Although of a large size and similarly silky, that species occurs primarily to the south of Durban, has a less elevated spire, and a more rapidly expanding and more evenly rounded body whorl in which the brown spiral line lies well above the periphery. K. inunctus , like K. vittarubra sp. nov. and several other Kerkophorus species from central and southern KwaZulu-Natal (e.g., K. phaedimus (Melvill & Ponsonby, 1892) and K. vitalis (Melvill & Ponsonby, 1908)) , possesses an enlarged genital atrium with a well-developed stimulator.

Conservation

The distribution of Kerkophorus vittarubra sp. nov. extends for approximately 200 km along the coast and coastal hinterland of central and southern Zululand. In this region it occurs in a number of formal conservation areas, including Ongoye, Dlinza and Enseleni nature reserves managed by Ezemvelo KZN Wildlife, as well as the southern part of the iSimangaliso Wetland Park World Heritage Site. Though not wide-ranging, its habitat is thus afforded a relatively high level of protection and the conservation of the species need not currently be viewed as a matter of concern.

Figures

Fig. 6. Distribution of Kerkophorus piperatus sp. nov. (triangles), Kerkophorus vittarubra sp. nov. (squares), and Microkerkus sibaya sp. nov. (cross). The population at Nkandla marked ‘?’ is a potentially hybrid population with shell characters resembling K. piperatus sp. nov., but with genitalia resembling K. vittarubra sp. nov. Contours at 1000 and 1500 m.

Fig. 7. Kerkophorus vittarubra sp. nov. A–D. Holotype, diameter 24.8 mm (NMSA P0353/T4061). E–F. Ongoye Forest, juvenile specimens with angular periphery (paratypes, NMSA W9692/T4046), diameter 17.5 mm and 16.0 mm, respectively.

Fig. 8. Kerkophorus vittarubra sp. nov., living animals. A. Maphelane, KwaZulu-Natal, shell diameter 18.3 mm (NMSA P0391). B. Enseleni, KwaZulu-Natal, shell diameter 12.6 mm (NMSA W4705). C–D. Ongoye Forest, KwaZulu-Natal, shell diameter 17.0 mm (NMSA P0386).

Fig. 9. Kerkophorus vittarubra sp. nov., radula (paratype, NMSA V4725/T4062). 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 = 200 μm; B–D = 100 μm.

Fig. 10. Kerkophorus vittarubra sp. nov., genitalia and spermatophore (paratype, NMSA V4725/T4062). A. Genital tract (minus ovotestis). B. Dissection of genital atrium and penis sheath revealing stimulator and sinuous penis. C. Spermatophore.

Fig. 2. Kerkophorus piperatus sp. nov. A–D. Holotype, diameter 18.6 mm (NMSA A8172/T4057). E. Hluhluwe Game Reserve, KwaZulu-Natal, diameter 18.4 mm (paratype, NMSA V2360/T4055). F. Ngome Forest, KwaZulu-Natal, diameter 18.8 mm (paratype, NMSA V2250/T4056). G. Mariepskop, Mpumalanga, diameter 13.0 mm (paratype, NMSA W9365/T4049). H. Possible K. piperatus × vittarubra hybrid, Nkandla Forest, KwaZulu-Natal, diameter 18.8 mm (NMSA W1116).