ABOUT OVATIPSA
COLOBA
Ovatipsa coloba (Melvill, 1888) inhabits
the
The name ‘coloba’ first
mentioned in a work by Melvill (1888) to designate a form of C. cruenta
Gmelin, 1791 “so called from the stunted appearance.” Melvill mentioned that in
this form “the base is always brighter coloured, and teeth interstices bright
red”; such a shell is figured in a work by Sowerby (1870) Pl. 23 # 190—Fig. 1
below.
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Cypraea cruenta Gmelin was later treated
as a synonym of Cypraea chinensis Gmelin (1791). In the Prodrome—Schilder
& Schilder (1938) the name coloba was recycled to designate a
possible new species closely related to chinensis. The Schilders wrote: “
The Indian coloba differs from chinensis by the orange instead
of whitish base and sides, and by the anterior and posterior columellar teeth
much coarser and more produced than the central ones, whereas in chinensis
all columellar teeth are equally short; besides, in coloba the lateral
spots are scarce instead of profuse, extending less over the base, and of a
less rich purple, while the dorsal specks are not so close, but never
interrupted by pale lacunae; the general shape, the aperture, and the fossula
of coloba approach chinensis variolaria.” |
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1. C. cruenta var. coloba; enlarged
pictured from a work by Sowerby (1870) |
Two subspecies were
described in the Prodrome:
O. coloba coloba from the
O. coloba greegori (Ford, 1893) from
India-Bombay to
Their description reads:
“In the Erythraean coloba
(23.71.15.15) the anterior and posterior columellar teeth seem to be less
produced than in the Indian greegori (26.73.15.14), the aperture is less
narrow, the right margin less swollen, and the fossular denticles are obsolete;
but we are not quite sure whether these characters are really racial.”
In Schilder & Schilder
(1952) this approach is the same.
Burgess (1970, 1985)
believed that coloba is an ecological variation of O. chinensis and
mentioned that it is “easily separable from the latter by its circular shape,
the depressed dorsum, the heavy coarser teeth, and the extremely callused
margins, the overall appearance of the two is very similar.”
Distribution
1) I did not find in the literature
reports confirming the presence of O. coloba coloba in the
Sharabati (1984), Verbinnen
et al. (1993), and Dekker & Orlin (2000) did not mention O. coloba
from the
Bosch (1982:65) treated chinensis-like
shells from
Bosch et al. (1995:73)
mentioned both chinensis (# 247) and coloba (#250) from
Coulombel (1993) did not mention chinensis and coloba
from
There are reports of finding
chinensis-like shells in Somalia; these shells are small (20-30 mm) and
similar to Fig. 1 above but their base is not orange as is coloba and
has the typical pink tinge characteristic of chinensis.
There are new sporadic
reports of finding chinensis-like shells in
2) Eastern group of coloba
populations.
Dharma (2005) pictured coloba
shells (about 27 mm) from
Thach (2005) mentioned only O. chinensis from
Most shells of O. coloba available currently to
shell collectors are from
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2. Approximate range of distribution of O. coloba |
A conclusion can be drawn that O. coloba
inhabits an area from South-West
Variability
A group of coloba shells in the author’s
collection can be seen in Figs. 2-19.
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2-3. |
4-5. |
6-7. |
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8-9. |
10-11. |
12-13. |
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14. |
15. |
16. No locality data, 27 mm |
There seems to be no
conchological gap between chinensis and coloba in the following
diagnostic characters:
-In coloba the
anterior and posterior columellar teeth much coarser and more produced than the
central ones, but this phenomenon can be found also in shells of chinensis-Fig.
17.
-Shells of coloba are
relatively small, oval and callused but such shells can be found in populations
of chinensis too-Figs. 18-22 (form dilatata).
-The lateral spots are
scarce instead of profuse in coloba, extending less over the base but
they are still well visible as in shells of chinensis.
-The dorsal specks are not
so close in coloba and seem to be never interrupted by pale lacunae but
this character is found also in chinensis—Fig. 19. A number of such shells in populations of chinensis
(form confused) from
-The teeth are whitish, and interstices of teeth are
dark orange in coloba but these characters can be found in shells of chinensis
especially in the
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17. O. chinensis,
anterior and posterior columellar teeth much coarser and more produced than the central ones |
18. O. chinensis,
28.5 mm, oval and callused shell |
19. O. chinensis,
dorsal specks are not interrupted by pale lacunae |
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20. O. chinensis, Hawaiian Is. the teeth are whitish, and interstices of teeth are dark orange |
21. O. chinensis,
33 mm, oval and callused shell |
22. O. chinensis, 28.5 mm, oval and callused shell |
The taxonomic identity
The Schilders studied a
total of 92 shells of coloba and listed it in Schilder & Schilder
(1971) as a subspecies of O. chinensis. This approach cannot be accepted
due to the following reasons:
O. coloba differs from O.
chinensis by one shell character—a rich orange color of the base and
margins. This difference is constant, without intermediate forms and it can be
interpreted as a conchological gap of a specific level between the two taxa or
as a form or stable mutant.
Mutants can be treated as
valid species—for example Erosaria eburnea (Barnes, 1824) or as forms,
for example Erronea onyx (Linnaeus, 1758) f. nymphaea, Erronea
errones (Linnaeus, 1758) f. azurea. In the latter case a blue mutant of E.
errones is treated as a form azurea because the blue shells are
sporadically found together with typical shells of errones in the same
area i.e. the blue mutant is not separated geographically from the typical
population and does not comprise the majority.
Analogically, rostrated and
melanotic shells from
Erosaria eburnea separated from Erosaria
miliaris by a conchological gap (white color) and geographically
(inhabiting mostly
O. coloba cannot be treated as an
ecological variation of O. chinensis as Burgess believed because it is
unknown in populations of the latter and there is no evidence that O.
chinensis and O. coloba share the same geographic area.
Currently, a decision regarding the taxonomic identity
of O. coloba seems to be only arbitrary. I suggest continuing to treat it
as a valid monotypic species until new information allows clarifying its
status.
O. coloba greegori is a synonym because there
is no evidence that coloba populations are living in the
Literature
Bosch D.
& Bosch, E. 1982. Seashells of
Bosch, D.T.,
Dance, S.P., Moolenbeek. R.G. & Oliver, P.G. 1995. Seashells of eastern
Burgess, C. M. 1985. Burgess’
Cowries of the World.
Coulombel, A. 1993. Coquillages
de Djibouti.
Dekker, H. & Orlin, Z. 2000.
Check-list of
Dharma, B. 2005. Recent & fossil Indonesian shells. Conchbooks. 424 pp.
Heiman E.L 2000. Variability of
cowry populations 5. About Erronea caurica (Linnaeus, 1758) from
“ caurica corrosa”. Triton 2:13-15.
2004. Diagnosing cowry species. Published privately. 160 pp.
2006. Intraspecific variation in living
cowries. Part 2. CD ROM Electronic book.
Lorenz F. & Hubert, A. 2000.
A Guide to worldwide Cowries. 584 pp.
Schilder F.A. & Schilder, M.
1938. Prodrome of a monograph on living Cypraeidae. Proc. of Malacological Society of
23:119-231.
Schilder F.A. & Schilder, M. 1952. Ph. Dautzenberg’s collection of Cypraeidae. Institute Royal des sciences naturelles de Belgique.
Bruxelles. 243 pp. + 4 Plates.
Schilder M. & Schilder F.A.,
1971. A catalogue of living and fossil
cowries. Institut Royal des sciences naturelles de Belgique. 246 pp.
Sharabaty, D. 1984.
Thach, N.N. 2005. Shells of
Verbinnen G., Wils E. &
Wellens, W. 1993.