Chondrocyclus pondoensis, Cole, 2019

Cole, Mary L., 2019, Revision of Chondrocyclus s. l. (Mollusca: Cyclophoridae), with description of a new genus and twelve new species, European Journal of Taxonomy 569, pp. 1-92 : 33-35

Chondrocyclus pondoensis sp. nov.

urn:lsid:zoobank.org:act:3913F1CE-3CB5-4B2F-AA60-BB811D014A4B

Figs 10 G–H, 16A, 17

Diagnosis

Shell small, depressed, lenticular; protoconch not mammillate; periostracum with dense, erect, transverse costae, expanded to form five spiral rows of raised flanges: a paddle-shaped row at periphery, a row of well-developed quadrangularly-shaped flanges around umbilicus and above periphery and a row of lower semi-circular flanges below suture; operculum duplex, lamella forming outer portion of operculum step shaped and terminating in a long solid fringe, portion above fringe consists of a lattice-like network of interwoven bristles some fused to fringe, projecting well above fringe and sloping inward towards centre; umbilicus wide and deep, exposing all the whorls; radula with three large cusps on second lateral tooth, cusps of rachidian, first and second lateral teeth fairly uniform in size; penis flattened dorsoventrally and laterally expanded about midway down the shaft, intromittent organ relatively long.

Etymology

Named for the distribution of the species, centered around the Pondoland region.

Type material examined

Holotype

SOUTH AFRICA – KwaZulu-Natal • Port Shepstone area, Marble Delta, Hlokohloko Valley , middle section, riverine/scarp forest; 30.6619° S, 30.3342° E; 175 m a.s.l.; Feb. 2012; J. Harvey leg.; in leaflitter; NMSA P 0643/ T 4160. ( Fig. 10 G–H)

Paratypes

SOUTH AFRICA – KwaZulu-Natal • 8 specimens; same collection data as for holotype, NMSA W 8763/ T 4161 • 2 specimens; same collection data as for preceding; NHMUK 20160079 • 1 specimen; same collection data as for preceding; RMNH. MOL.338286 • 8 specimens; Port Shepstone area, Marble Delta, Hlokohloko Valley , middle section, riverine/scarp forest; 30.6608° S, 30.3325° E; 188 m a.s.l.; in leaf-litter, Feb. 2012; J. Harvey leg.; in leaf-litter; NMSA W 8733/ T 4162 • 2 specimens; same collection data as for preceding; NMW. Z.2016.003.00002 • 2 specimens; Port Shepstone area, Marble Delta, Hlokohloko Valley , middle section, riverine/scarp forest; 30.6622° S, 30.3386° E; 145 m a.s.l.; Feb. 2012; J. Harvey leg.; in leaf-litter; NMSA W 8765/ T 4171 • 1 specimen; same collection data as for preceding; RMNH. MOL.338287 • 17 specimens; Port Shepstone, Simuma area, Hlokohloko valley , riverine/scarp forest; 30.6631° S: 30.3368° E; ca 150–200 m a.s.l.; 5 Mar. 2011; Herbert and Davis leg.; in leaf-litter; NMSA W 7844/ T 4144 • 7 specimens; Umtamvuna Nature Reserve, Port Edward, Old Pont Road , 2.5 km upstream of mouth; 31.0603° S, 30.1725° E; 56 m a.s.l.; 13 Apr. 2011; M. Cole, D. Herbert, L. Davies and R. Daniels leg.; ELM D16940/ T 113 • 5 specimens; same collection data as for preceding; ELM W 03627/ T 114 • 2 specimens; same collection data as for preceding; NHMUK 20120271 . – Eastern Cape • 1 specimen; Mtentu , north bank; 31.2400° S, 30.0367° E; 20 May 2005; M. Bursey and V. Ndibo leg.; ELM W 03027/ T 109 • 2 specimens; Mtentu , north bank, 1.5 km upstream, inlet to first waterfall, on east side of inlet; 31.2389° S, 30.0340° E; 13 Jan. 2012; M. Cole leg.; ELM D17406/ T 110 • 1 specimen; same collection data as for preceding; ELM W 03602/ T 111 • 1 specimen; Mtentu , north bank, 3 km upstream of mouth, inlet to second waterfall, west side of inlet; 31.2295° S, 30.0182° E; 43 m a.s.l.; 12 Jan. 2012; M. Cole leg.; ELM W 03603/ T 112 • 1 specimen; Mkambati Nature Reserve, ‘ Superbowl’ forest, 5 km upstream of Msikaba mouth, east side of Msikaba River ; 31.2978° S, 29.9293° E; 3 May 2004; M. Bursey leg.; in leaf-litter; ELM D14256/ T 107 • 2 specimens; same collection data as for preceding; 18 May 2005; ELM D15585/ T 108 • 1 specimen; Mbotyi, Drewes camp, east of village, dune forest at east end of beach, just before cliffs; 31.4432° S, 29.7686° E; 13 Jan. 2003; M Bursey leg.; ELM D14396 / T 106 • 1 specimen; Ntafufu , below lodge, west bank, 2 km upstream of mouth; 31.5514° S, 29.6175° E; 24 Apr. 2005; D.- J. Hodgkinson leg.; ELM D15532/ T 101 • 2 specimens; Ntafufu , east bank, 1.5 km upstream of mouth; 31.5565° S, 29.6261° E; 24 Apr. 2005; M. Bursey leg.; ELM D15531/ T 102 • 2 specimens; Mpame forest ; 32.0856° S, 29.0306° E; 19 Feb. 2009; M. Cole leg.; ELM D16941/ T 105 • 2 specimens; Xora, Kumqolo Forest, west bank of Xora River opposite mangrove swamp; 32.1589° S, 28.9848° E); 25 Oct. 2005; M. Bursey leg.; ELM D15537/ T 103 • 1 specimen; same collection data as for preceding; 13 Aug. 2011; M. Cole leg.; ELM W 03663/ T 104 • 1 specimen; Manubi forest ; 32.4426° S, 28.6130° E; 3 Oct. 2017; M. Cole leg.; ELM W 04034/ T 203 .

Description

SHELL ( Fig. 17 A–C). Small, depressed, lenticular, adult diameter 4.59–6.18 mm, height 2.42–3.42 mm, diameter:height 1.59–2.00 (n = 19). Spire not much raised, protoconch not mammillate. Embryonic shell just over 1.5 whorls, microscopically malleate, junction between embryonic shell and teleoconch not particularly distinct, initially costae weak, becoming well developed after about a quarter of a whorl ( Fig. 17D ). Teleoconch comprising 2.75 whorls, moderately convex, rapidly increasing, suture deeply impressed. Aperture circular, last whorl descending near aperture, peristome simple, continuous and free. Umbilicus wide and deep, exposing all the whorls. Periostracum glossy, honey-brown and lacquer-like with dense lamellate costae at regular intervals, approx. 154–184 (n = 14) on last whorl, expanded into five spiral rows of flanges: a paddle-shaped row at periphery, a row of well-developed quadrangularly-shaped flanges around umbilicus and above periphery and a row of lower semi-circular flanges below suture; flanges bear numerous axial riblets visible at very high magnification ( Fig. 17E ); intervals between costae with microscopic axial threads. Shell translucent, glossy, corneous yellowbrown when fresh.

LIVING ANIMAL. Creamy white with slight pigmentation on tentacles.

OPERCULUM ( Fig. 17 G–H). Duplex, outer portion consists of multispiral lamella with 4.5–5 whorls; lamellar blade high, stepped, long fringe emanates near top of vertical portion of blade; blade projects high above fringe and slopes inward towards centre, upper portion of lamellar blade consists of latticelike network of interwoven bristles, some bristles connected to main fringe so there is no groove between fringe and lamellar blade ( Fig. 17G ); at the growing edge the top portion of lamellar blade is more or less square, not sloping, becoming arrow shaped below fringe ( Fig. 17H ). Outer lamellar fringe reflexed over peristome preventing animal withdrawing into shell.

RADULA ( Fig. 17F ). Rachidian with five cusps, central one slightly longer; first and second laterals each with three large cusps, a smaller fourth and a vestigial fifth, cusps increase in size very slightly from central tooth outwards, but there is not a large difference in size between cusps.

PENIS ( Fig. 17 I–J). Expanded towards distal end, intromittent organ relatively long.

Distribution and habitat

Known primarily from near the coast between Xora in Transkei and Umtamvuna in southern Kwazulu- Natal, and also recorded inland in the Port Shepstone area (ca 200 m a.s.l.) ( Fig. 16A ). (The Transkei is the area of the Eastern Cape Province between the Kei and Umtamvuna Rivers.)

Indigenous Scarp Forest of the Pondoland Gorge and Transkei Coastal Scarp subtypes ( von Maltitz et al. 2003), adjacent to rivers, in leaf litter. Scarp forests are a forest type occurring on south- and east-facing hills and gorges of the first plateau escarpment (300– 1100 m) and unique to the east of South Africa.

Remarks

Morphologically, C. pondoensis sp. nov. resembles C. trifimbriatus in features of the periostracum, operculum and radula. The position of spiral rows of flanges is equivalent in C. pondoensis sp. nov. and C. trifimbriatus specimens from the type locality. The radulae have teeth with cusps relatively uniform in size. The operculum of C. pondoensis sp. nov. is flatter than that of coastal species of Chondrocyclus . However, it is distinguished from that of C. trifimbriatus by the outer lamellar blade projecting high above the fringe and sloping towards the centre and a well-developed lattice of interwoven bristles joining the lamellar blade to the fringe ( Fig. 17G ). Other species bearing a lattice of interwoven bristles at the top edge of lamellar blade, fused with the main fringe are the coastal C. putealis Conolly, 1939 , C. bathrolophodes Conolly, 1929 and C. cooperae sp. nov. but these species have a relatively deep operculum.

In the molecular study, C. pondoensis sp. nov. did not appear related to C. trifimbriatus or to any other lineages ( Cole et al. 2019).

In coastal areas of Transkei where C. pondoensis sp. nov. is sympatric with C. putealis and C. cooperae sp. nov. specimens appeared to be scarce and patchily distributed, while at localities in southern KwaZulu-Natal (Umtamvuna Nature Reserve and Hlokohloko valley inland of Port Shepstone) where C. pondoensis sp. nov. was the only Chondrocyclus species recorded, specimens appeared to be common.

Figures

Fig. 10. Holotypes of species of Chondrocyclus Ancey, 1898. A–B. C. herberti sp. nov., diameter 3.70 mm (NMSA P1043/T4277). C, F. C. silvicolus sp. nov., diameter 5.82 mm (NMSA P0639/T4156). D–E. C. amathole sp. nov., diameter 6.01 mm (NMSA P0640/T4157). G–H. C. pondoensis sp. nov., diameter 5.92 mm (NMSA P0643/T4160). I, L. C. devilliersi sp. nov., diameter 5.23 mm (NMSA P1141/ T4312). J–K. C. pulcherrimus sp. nov., diameter 4.34 mm (NMSA W9272/T3075). M–N. C. cooperae sp. nov., diameter 4.93 mm (NMSA W9271/T3074). O, R. C. langebergensis sp. nov., diameter 5.13 mm (NMSA P0642/T4159). P–Q. C. kevincolei sp. nov., diameter 4.24 mm (NMSA P9270/T3073).

Fig. 17. Chondrocyclus pondoensis sp. nov. A. Aperture view (ELM W3602/T111). B. Dorsal view (ELM W3627/T114). C. Ventral view (ELM W3627/T114). D. Protoconch (NMSA W8733). E. Detail of axial lamellae of periostracum (ELM W3627/T114). F. Portion of radula (ELM W3627/T114). G–H. Operculum (ELM W3627/T114). I. Penis, lateral view (NMSA W7844/T4144). J. Penis, dorsal view (ELM W3627/T114). Scale bars: A–C = 2 mm; D = 200 µm; E, H = 500 µm; F = 50 µm; G, I–J = 1 mm.

Fig. 16. Distribution map of Chondrocyclus species in the Eastern clade. A. Species in KwaZulu-Natal and the eastern half of the Eastern Cape, on the coast and extending inland. B. Species on the Eastern Cape coast. Note that the range of C. pondoensis sp. nov. overlaps with that of C. putealis Connolly, 1939 and C. cooperae sp. nov. T indicates type localities. Major cities and rivers are labelled.