Revision of Chondrocyclus s. l. (Mollusca: Cyclophoridae), with description of a new genus and twelve new species
Author
Cole, Mary L.
East London Museum, P. O. Box 11021, Southernwood, 5213, South Africa and Department of Zoology and Entomology, Rhodes University, P. O. Box 94, Grahamstown (Makhanda) 6140, South Africa.
marybursey@elmuseum.za.org
text
European Journal of Taxonomy
2019
2019-10-22
569
1
92
journal article
10.5852/ejt.2019.569
ee4333ce-4fde-4a61-85e9-effa3d1b5999
2118-9773
3517522
79BE13FC-B840-4C39-8D25-3328BDCC44D2
Afrocyclus isipingoensis
(
Sturany, 1898
)
gen. et comb. nov.
Figs 27
,
28A
,
29
Cyclotus isipingoensis
Sturany, 1898: 161
(
type
loc.: Isipingo [Penther]).
Cyclophorus minimus
Melvill & Ponsonby, 1898: 129
, pl. vii, fig. 9 (
type
loc.: Pietermaritzburg [Burnup]).
Cyclophorus
(
Maizania
)
isipingoensis
–
Kobelt 1902: 149
.
Chondrocyclus isipingoensis
–
Connolly 1939: 540
. —
Herbert & Kilburn 2004: 91
.
Cyclophorus minimus
– Melville & Ponsonby 1899
: pl. iii, fig. 15 (operculum).
Diagnosis
Shell very small, very depressed, discoidal; periostracum with axial costae producing spiral rows of simple hairs; operculum very fragile and duplex, exterior portion very shallowly concave, with low multispiral lamella terminating in a solid fringe; rachidian tooth of radula with serrated upper edge, two large cusps on second lateral tooth.
Etymology
Named after the
type
locality, Isipingo,
KwaZulu-Natal
,
South Africa
.
Type material examined
Holotype
SOUTH AFRICA
–
KwaZulu-Natal
•
holotype
of
Cyclotus isipingoensis
Sturany, 1898
; in Vienna Museum, not examined; NHMW.
Syntype
SOUTH AFRICA
–
KwaZulu-Natal
•
syntype
of
Cyclophorus minimus
Melvill & Ponsonby, 1898
; Pietermaritzburg;
Burnup
leg.;
NHMUK 1902.10
.1.7
.
Other material examined
SOUTH AFRICA
–
Limpopo
•
99 specimens
;
Soutpansberg
,
Dundee Forest
;
23.017° S
,
29.515°E
;
24 Jul. 1999
;
C. Symons
leg.; sorted from leaf litter;
NMSA
V7513
•
77 specimens
;
Soutpansberg
,
Entabeni
,
Goedehoop
, indigenous forest;
23.0833° S
,
30.1117°E
; ±
950 m
a.s.l.
;
20 Nov. 1997
;
D. Herbert
leg.; in leaf-litter;
NMSA
V5658
. –
Mpumalanga
•
119 specimens
;
Buffelskloof Nat. Res.
, indigenous forest;
25.3169° S
,
30.4990°E
;
1300 m
a.s.l.
;
15 Mar.
2006
;
J. Horn
leg.; in leaf-litter;
NMSA
W4486
. –
KwaZulu-Natal
•
28 specimens
;
Ngoye Forest
, lower section, coastal scarp forest;
28.8330° S
,
31.7170° E
; ±
250 m
a.s.l.
;
6 Sep. 1997
;
D. Herbert
leg.; in leaf litter;
NMSA
V5861
•
6 specimens
;
Nkandla Forest Reserve
,
Mdonini area
, mist-belt forest;
28.7453° S
,
31.1357° E
; ±
1050 m
a.s.l.
;
21 Oct. 2003
;
Herbert
,
Bursey
and
Nangammbi
leg.; under logs and in leaf-litter;
NMSA
W
1103
•
58 specimens
;
Vernon Crookes Nat. Res.
, small patch of scarp forest;
30.2750°S
,
30.5830° E
;
1 Jan. 2004
;
D. Herbert
leg.; in thin layer of leaf-litter on flat-topped boulder;
NMSA
W1441
•
28 specimens
;
Loteni
,
Yellow-Wood Cave area
montane
Podocarpus
forest;
29.4150°S
,
29.4800°E
;
1800 m
a.s.l.
; in leaf-litter;
25 Oct.
1997
;
D. Herbert
leg.;
NMSA
V5752
•
30 specimens
;
Karkloof Falls
, near top of gorge,
Southern Mistbelt Forest
;
29.4088° S
,
30.2840°E
;
22 Jan. 2010
;
M. Cole
leg.;
ELM
D16902
•
3 specimens
; same collection data as for preceding;
ELM
W03650
•
1 specimen
;
Karkloof Nature Reserve
;
29.3150° S
,
30.2500° E
;
1350 m
a.s.l.
;
23 Jan. 2010
;
M. Cole
leg.;
ELM
D16903
•
17 specimens
;
Kenneth Stainbank
N.R,
Yellowwood Park
;
29.9122° S
,
30.9390°E
;
12 Jan.
2010
;
M. Cole
and
K. Cole
leg.;
ELM
D16897
•
34 specimens
; same collection data as for preceding;
12 Apr. 2011
;
M. Cole
,
R. Daniels
,
L. Davis
and
D. Herbert
leg.;
ELM
D16898
•
1 specimen
; same collection data as for preceding;
ELM
W03648
•
3 specimens
; same collection data as for preceding;
NHMUK 20120268
•
2 specimens
; same collection data as for preceding;
NMW
.Z.2012.065.00001
•
1 specimen
;
Kranskop area
,
Ntumjambili
, indigenous forest;
28.9380°S
,
30.9550°E
; ±
900 m
a.s.l.
;
9Aug. 1997
;
D. Herbert
leg.; in leaf-litter;
NMSA
V5105
•
3 specimens
;
Kelso
, dune forest behind railway station;
30.3622°S
,
30.71316° E
;
24 m
a.s.l.
;
31 Oct. 2010
;
M. Cole
leg.;
ELM
D17635
. –
Eastern Cape
•
2 specimens
;
Mtentu
, north bank, inlet
1.5 km
upstream to first waterfall from mouth, east side of inlet;
31.2389°S
,
30.0340° E
;
30 m
a.s.l.
;
13 Jan.
2012
;
M. Cole
leg.;
ELM
D17086
•
1 specimen
; same collection data as for preceding;
ELM
W03604
•
1 specimen
;
Mtentu
, north bank, inlet
3 km
upstream of mouth, west side of inlet;
31.2295°S
,
30.0182° E
;
43 m
a.s.l.
;
12 Jan. 2012
;
M. Cole
leg.;
ELM
D17006
•
1 specimen
; same collection data as for preceding;
ELM
W03605
•
7 specimens
;
Mkambati Nature Reserve
, between
Mkambati
and
Strandloper Falls
, forest on east bank of
Mkambati River
;
31.2738° S
,
30.0236°E
;
15 Feb. 2011
;
M. Cole
leg.;
ELM
D16913
•
5 specimens
; same collection data as for preceding;
ELM
W03653
•
3 specimens
;
Mkambati
, east bank
Msikaba
mouth;
31.3183° S
,
29.9683° E
;
16 Feb. 2011
;
M. Cole
leg.;
ELM
D16914
•
1 specimen
;
Mkambati
,
Gwe Gwe forest
, forest above
Gwe Gwe
cottages;
31.2904°S
,
29.9897°E
;
5 Mar.
2001
;
M. Cole
leg.;
ELM
D17004
•
1 specimen
;
Mkambati Nature Reserve
,
Daza forest
;
31.3025° S
,
29.9767°E
;
16 Feb. 2011
;
M. Cole
leg.;
ELM
W03688
•
2 specimens
;
Mbotyi
,
Ntsubane Forest
, inland of coast, accessed along
KwaNyambalala River
;
31.4615° S
,
29.7129°E
;
3 Mar. 2003
;
M. Bursey
leg.;
ELM
D17363
•
2 specimens
;
Xora
,
Kumqolo Forest
, west bank of
Xora river
opposite
Mangrove
swamp;
32.1589° S
,
28.9848° E
;
13 Aug. 2011
;
M. Cole
leg.;
ELM
D17584
•
5 specimens
;
Qora
,
East Bank of Qora River
, riverine forest;
32.4333° S
,
28.6667° E
;
7 Nov.
2009
;
M. Cole
leg.;
ELM
D16904
•
1 specimen
; same collection data as for preceding;
ELM
W03651
•
1 specimen
; same collection data as for preceding;
9 Oct. 2011
;
M Cole
leg.;
ELM
D17000
•
17 specimens
;
Phumalanga Farm
,
7 km
inland of
Cintsa
, riverine forest on
Bulura River
;
32.8067° S
,
28.0306°E
;
25 Apr. 2006
;
Bursey
,
Wigley
and
Ndibo
leg.;
ELM
D15030
•
12 specimens
; same collection data as for preceding;
12 Dec. 2008
; M.
Wigley
;
ELM
D15870
•
23 specimens
; same collection data as for preceding;
16 Nov.
2009
;
M. Cole
and
M. Wigley
leg.;
ELM
D16899
•
19 specimens
; same collection data as for preceding;
1 Dec. 2009
; M.
Wigley
;
ELM
D16900
•
11 specimens
; same collection data as for preceding;
ELM
W03686
•
51 specimens
; same collection data as for preceding;
31 Dec. 2010
;
M. Cole
leg.;
ELM
D16901
•
9 specimens
; same collection data as for preceding;
ELM
W03649
•
1 specimen
;
Umtiza Nature Reserve
,
Tree Dassie
trail on east side of
Buffalo Pass
;
33.0169° S
,
27.8092°E
;
21 Apr. 2006
;
M. Bursey
leg.;
ELM
W03008
•
3 specimens
; same collection data as for preceding;
8 Jun.
2010
;
M. Cole
leg.;
ELM
D16905
•
8 specimens
; same collection data as for preceding;
13 Jan. 2011
;
V. Ndibo
,
J. Glatz
and
R. Daniels
leg.;
ELM
D16906
•
5 specimens
; same collection data as for preceding;
ELM
W03652
•
5 specimens
; same collection data as for preceding;
20 May 2011
;
M. Cole
leg.;
ELM
D16907
•
7 specimens
; same collection data as for preceding;
18 Mar. 2011
;
M. Cole
leg.;
ELM
D16908
•
1 specimen
; same collection data as for preceding;
1 Dec.
2011
;
M. Cole
leg.;
ELM
D16909
•
1 specimen
;
Hogsback
, downstream of
Madonna
and
Child Waterfall
;
32.6068°S
,
26.9622° E
;
1060 m
a.s.l.
;
25 Jan. 2002
;
M. Bursey
leg.;
ELM
W02835
•
1 specimen
;
Hogsback
,
Amathole Mountains
,
Kettlespout
, forest above
Hobbiton
;
32.5667° S
,
26.9167° E
;
31 Dec. 2008
;
M. Cole
leg.;
ELM
D17007
•
10 specimens
;
Amathole Mountains
,
Stutterheim
,
Kologha Forest
, near picnic site,
Southern Mistbelt forest
;
32.5339° S
,
27.4308° E
;
22 Dec.
2009
;
M. Cole
leg.;
ELM
D16910
•
2 specimens
;
Stutterheim
,
Kologha Forest
, forest drive near
Protea Hill
;
32.5339° S
,
27.4308°E
;
26 Jan. 2010
;
M. Cole
leg.;
ELM
D16911
•
3 specimens
;
Stutterheim
,
Contour
path;
32.5366°S
,
27.3668°E
;
16 Jan. 2015
;
M. Cole
leg.;
ELM
D17873
•
2 specimens
;
Maden Dam
,
18 km
N.W.
of
King Williams Town
;
32.7333° S
,
27.2833°E
;
26 Mar. 2011
;
D.-J. Hodgkinson
leg.;
ELM
D16912
•
9 specimens
;
Fort Fordyce
, kloof with watercourse and sheer krantz;
32.6893°S
,
26.5121° E
;
915 m
a.s.l.
;
29 Dec.
2008
;
M. Cole
leg.;
ELM
D16916
•
2 specimens
; same collection data as for preceding;
6 Oct. 2009
;
M. Cole
leg.;
ELM
D16961
.
Description
Specimens from Kenneth Stainbank Nature Reserve, Durban, approx.
9 km
from the
type
locality Isipingo, are considered to represent the
type
in the following description.
SHELL (
Fig. 27
A–C). Very small, very depressed, discoidal, adult diameter
2.24–3.67 mm
, height
1.09– 1.67 mm
, diameter:height 1.9–2.31 (n = 16) Spire almost flat, sometimes concave, usually with only the weakly mammillate, slightly tilted protoconch projecting (
Fig. 27A
). Embryonic shell (
Fig. 28A
) approx. 2.25 whorls, microscopically malleate for approx. two whorls, axial costae begin to develop at about 2.25 whorls. Teleoconch comprising just over two whorls, very rapidly increasing, convex, suture impressed. Aperture circular, last whorl descending steeply nearing aperture, peristome simple, continuous and free. Umbilicus very wide, exposing all the whorls (
Fig. 27C
). Periostracum glossy and lacquer-like with lamellate well-spaced axial costae at regular intervals, the average number on last whorl varying between 55 and 92 (
Table 5
), which produce 10–12 spiral rows of simple hairs, longest at periphery (four rows) with approx. five–seven rows between periphery and umbilicus, the latter becoming progressively shorter nearer the umbilicus, and one very short row immediately below the suture; intervals between costae usually with six to nine microscopic axial threads (
Fig. 27D
). Shell translucent when fresh.
Fig. 27.
Afrocyclus isipingoensis
(
Sturany, 1898
)
gen. et comb. nov.
A
. Aperture view (ELM W3648).
B
. Dorsal view (ELM W3648).
C
. Ventral view (ELM W3648).
D
. Detail of axial lamellae of periostracum (ELM D16897).
E
. Portion of radula (ELM W3650).
F
. Penis, dorsal view, showing position behind right tentacle (ELM W3652).
G
. Operculum, inner portion, showing tubercle (ELM W3648).
H
. Operculum of specimen from near type locality (ELM W3648).
I
. Operculum of specimen from Mpumalanga (NMSA W4486). Scale bars: A–C = 2 mm; D, F–H = 500 µm; E = 20 µm; I = 200 µm.
Fig. 28.
Protoconch detail of species of
Afrocyclus
gen. nov.
A
.
Afrocyclus isipingoensis
(
Sturany, 1898
)
gen. et comb. nov.
from Durban (near type locality) (ELM W3648).
B
.
A. oxygala
gen. et sp. nov.
(ELM W3647).
C
.
A. potteri
gen. et sp. nov.
(ELM W4052).
D
.
A. bhaca
gen. et sp. nov.
(NMSA V4889). Scale bars: A–D = 200 µm.
Table 5.
Measurements of populations of the
Afrocyclus isipingoensis
(
Sturany, 1898
)
gen. et comb. nov.
species complex; D = shell diameter, H = height, costae = number of axial ribs on body whorl, Avg = average.
Site
|
D max D min
|
Avg
|
H max H min
|
Avg
|
D/H max
|
D/H min
|
Avg
|
n
|
Costae
|
Avg
|
n
|
Kenneth Stainbank |
3.67 |
2.24 |
2.88 |
1.67 |
1.09 |
1.41 |
2.31 |
1.90 |
2.05 |
16 |
55–92 |
75 |
14 |
Vernon Crookes |
3.26 |
2.39 |
2.89 |
1.71 |
1.07 |
1.46 |
2.24 |
1.84 |
2.00 |
13 |
52–66 |
60 |
12 |
Upper Bulura |
3.00 |
2.24 |
2.59 |
1.68 |
1.02 |
1.24 |
2.55 |
1.67 |
2.12 |
21 |
28–40 |
34 |
8 |
Soutpansberg |
3.10 |
2.24 |
2.75 |
1.48 |
1.12 |
1.31 |
2.38 |
1.89 |
2.09 |
10 |
59–72 |
64 |
7 |
Lotheni |
3.16 |
2.42 |
2.82 |
1.55 |
1.14 |
1.35 |
2.29 |
2.00 |
2.10 |
6 |
40–41 |
41 |
2 |
Ongoye |
3.63 |
2.96 |
3.22 |
1.75 |
1.08 |
1.41 |
2.75 |
2.09 |
2.30 |
14 |
61–88 |
75 |
10 |
Nkandla |
4.11 |
2.96 |
3.52 |
1.88 |
1.48 |
1.73 |
2.18 |
1.93 |
2.03 |
3 |
68–70 |
69 |
2 |
A. oxygala
Bedford
|
2.80 |
2.19 |
2.53 |
1.43 |
1.12 |
1.27 |
2.12 |
1.87 |
1.99 |
9 |
63–81 |
69 |
7 |
A. oxygala
Glen Avon
|
3.00 |
2.49 |
2.76 |
1.68 |
1.32 |
1.49 |
2.04 |
1.61 |
1.86 |
20 |
76–95 |
85 |
12 |
A. bhaca
Ngele
|
3.72 |
2.80 |
3.12 |
1.78 |
1.22 |
1.46 |
2.33 |
1.83 |
2.14 |
13 |
46–65 |
53 |
10 |
A. bhaca
Mount Frere
|
2.75 |
2.49 |
2.65 |
1.22 |
0.97 |
1.11 |
2.58 |
2.21 |
2.39 |
6 |
48–58 |
54 |
5 |
A. potteri
Langeni
|
3.51 |
2.19 |
3.03 |
1.68 |
1.02 |
1.36 |
2.41 |
2.04 |
2.23 |
14 |
47–67 |
55 |
7 |
A. potteri
Moonstone
|
2.82 |
2.17 |
2.44 |
1.38 |
1.03 |
1.22 |
2.20 |
1.70 |
2.01 |
31 |
31–45 |
37 |
17 |
OPERCULUM (
Fig. 27
E–F). Very fragile and duplex, outer portion consists of multispiral lamella with five–six whorls, height of lamellar blade very low thus operculum is very shallowly concave to almost flat, thickened horizontal ridge on lamellar blade just above disc surface; long fringe of fused bristles emanates from this ridge, fused to blade and then curving outwards, leaving no furrow between fringe and vertical portion of blade, fringe of each whorl fused to lamella of following whorl, fringe of outer whorl fairly long and overlaps disc slightly; inner portion of operculum is a thin disc, in some populations side of disc facing body has a prominent tubercle or swelling in centre (
Fig. 27F
).
RADULA (
Fig. 27G
). Rachidian with five cusps, central one very long, outermost two very small to almost vestigial, cusps set a little distance below ‘top’ of tooth, top edge serrated; first lateral tooth with four cusps and a vestigial fifth, third cusp (from centre) largest; second lateral tooth with two large cusps, second cusp (from centre) largest, a third small cusp and a vestigial fourth.
PENIS (
Fig. 27H
). Shaft more or less cylindrical and laterally expanded on left side about midway down the shaft.
Distribution and habitat
This species complex is widely distributed throughout the eastern region of
South Africa
, from Soutpansberg mountains in
Limpopo Province
to the Amathole mountains in the
Eastern Cape
; from the coast to the Drakensberg foothills (
1800 m
) (
Fig. 29
).
Indigenous forest of several classification
types
(
Mucina & Geldenhuys 2006
): Southern and Northern Coastal Forest, Scarp Forest, Southern and Northern Mistbelt Forest, Northern Afrotemperate Forest, and Albany Thicket (Kowie Thicket) (
Hoare
et al.
2006
); in leaf-litter.
Remarks
Selected populations from across the range of this lineage were sampled for the molecular study and morphological examination and there is compelling evidence that
A. isipingoensis
gen. et comb. nov.
is a species complex rather than one widespread species. Until further study is undertaken the name
A. isipingoensis
gen. et comb. nov.
is applied to all populations with the exception of the three new species described below. Differences in the density of axial lamellae, the number and position of spiral rows of hairs, the length of the hairs, the density of microscopic axial threads between the lamellae and the strength of protoconch sculpture will need to be evaluated in conjunction with molecular evidence from more comprehensive coverage of the range of the complex.
The phylogeny inferred suggests that populations from the western end of the range (
Somerset
East and
Bedford
) belong to a distinct lineage (
A. oxygala
gen. et sp. nov.
). There was also a well-supported lineage in montane areas between the coast and Great Escarpment in the central Transkei (
A. potteri
gen. et sp. nov.
) and another lineage occurring in relatively close proximity in the north-eastern Transkei (
A. bhaca
gen. et sp. nov.
). The population from near the
type
locality had one row of extremely short hairs on lamellate costae immediately below the suture, and a gap with no hairs between this and the four rows of very long hairs near the periphery (
Fig. 27D
).
Afrocyclus oxygala
gen. et sp. nov.
(
Fig. 30D
),
A. potteri
gen. et sp. nov.
(
Fig. 31
D–E) and
A. bhaca
gen. et sp. nov.
(
Fig. 32D
) lacked the extremely short row just below the suture.
Fig. 29.
Distribution map of
Afrocyclus
gen. nov.
T indicates type localities. Provinces and major cities are labelled.
The rachidian tooth of the radula is unusual in having a serrated upper edge and the cusps are set a little distance below the ‘top’of tooth.
Afrocyclus isipingoensis
gen. et comb. nov.
(
Fig. 27G
),
A. exsertus
gen. et comb. nov.
(
Fig. 33G
),
A. potteri
gen. et sp. nov.
(
Fig. 31G
) and
A. bhaca
gen. et sp. nov.
(
Fig. 32E
) showed this feature while the upper edge of the rachidian tooth of
A. oxygala
gen. et sp. nov.
(
Fig. 30G
) was not serrated as in species of
Chondrocyclus
s.s.