Conus desidiosus (Adams, 1854)
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1854 |
Conilithes desidiosus |
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Fig. 1 - Conilithes desidiosus
(Adams, 1854) Lectotype 1958098 - mm. 24,1 x 11,6 ©Kevin
Webb, NHMUK Photographic Unit. Natural History Museum of London |
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In the
original description of the specimens belonging to the Cuming Collection by
Adams of 1854, this shell is described as pyramidal and conical, with the base crossed by oblique grooves,
enough deeply incised; last whorl has a light brown base color
and is crossed by a wide whitish band, interrupted by numerous brown color
lines, and with wavy lines whitish on the back. The spire is high and
conical, the suture ramps are flat, with two spiral incised lines in the
median part, the lip is arcuate, with a depression in the rear. In
correspondence of the shoulder there is a grid formed by reddish lines, but curved longitudinal lines of the same color are present on all the spires. In the
anterior part of each spire, the reddish lines terminate in stains that tend to join together, to form almost a band, while the carena remains largely of white color. The dimensions of the specimen described by Adams, from the Cuming
collection, are 24.1 x 11.6 mm. The origin indicated by Adams is West Africa. |
Over the
years no other specimens of Conus desidiosus have been found, but
malacologists have not desisted from trying to find other specimens of this
species, describing specimens of other species such as Conus desidiosus,
based on the similarity of the coloring and completely neglecting any relative
consideration. to the morphology. Below I list the different interpretations of
Conus desidiosus that have been hypothesized.
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1855-1879 |
Conus mercator |
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In the
early years following Adams' description, Conus desidiosus was
depicted in drawings inspired by the representation given by Sowerby in 1855 (Fig. 1), and was put in relation
with Lautoconus mercator, surely based on the presence on the shoulder
of Conus desidiosus of a kind of grid, but the morphological diversity
and the different colors of the two species do not to suggest a possible
relationship between them (Küster et. al., 1875 - Fig. 2 and Tryon
et. al., 1879
- Fig.
3). Sowerby's
design (Fig. 1) undoubtedly depicts Conus desidiosus,
but represents it with two obvious errors, probably caused by his conviction
that Conilithes desidiosus was a variety of Lautoconus mercator.
In Sowerby's design: q
the
spire is concave rather than straight; q
the
shoulder is overly rounded and, as a
result, the spire is significantly less wide than it is in the lectotype.
·
TRYON W., PILSBRY H. A., SHARP B., 1879. Manual
of conchology, structural and systematic: with illustrations of the species
vol. VI |
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Fig. 1 - Conus desidiosus (Conus mercator, var.) Vol. 3 - Plate XIV n. 306 (Sowerby G.B., 1855) |
Fig. 2 - Conus desidiosus (Conus mercator, var.) Plate 68 n. 10 |
Fig. 3 - Conus desidiosus (Conus mercator, var.) Plate 16 n. 23 |
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In Conus mercator, coloration consists
of a reticulum formed by small rounded spots, aligned obliquely, similar to
the coloration visible at the shoulder in Conus desidiosus, but the
morphology of the shell is completely different.
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Conus mercator mm 33,2 x 18,2 Is. Goreé -
Dakar (Senegal) [AZRC N. 711-01] |
Conus desidiosus
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1974 |
Conus cuneolus |
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In
1974 Petuch places Conilithes desidiosus into the Africonus
genus and depicted it by a specimen (Fig. 4) of Africonus cuneolus. ·
PETUCH E.J., 1974.“A
Review of the Small Mauretanian Conus Shells with Description of a New Genus
and a New Species„, THE VELIGER 17(3): 262-263 The
coloring of this specimen is really particular and resembles that present on
the shoulder of Conus desidiosus,
but a simple comparison with the holotype is enough to realize that the two
species are completely alien to each other. |
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Fig. 4 - Africonus
desidiosus (mercator,
var.) (Edward J. Petuch, 1974 – Fig. 2) |
Cape Verde, Boa Vista, Ilheu de Sal Rei, Mordeira Bay, on coral, at 2
m depth, collected 1998, ex coll. J. Trausel. Image by Joop Trausel and Frans Slieker |
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1979 |
Conus taslei |
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In
1979 Walls put Conilithes desidiosus in synonymy with L. taslei. Also
in this case, the coloring is really particular and similar to that of Conus
desidiosus, demonstrating that some specks of coloring are common to many
species and are therefore not sufficient for determining whether or not a
specimen belongs to a certain species. The shape of the spire is so different
that it could not be included in the variability of the species. ·
WALLS, J. G.,
1979. “Three
new Indian Ocean cones (Mollusca: Conidae)”. The Pariah, 5: 1 - 6 |
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Fig. 5 - Conus taslei Bubaque, Guinea Bissau, W.Africa |
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1985 |
Conus guanche |
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In 1978, Saunders
described some specimens of Lautoconus cf. guinaicus (Fig. 6). In 1985, with reference
to the same specimens indicated by Saunders as Lautoconus cf. guinaicus (v.
Fig. 6 - Raybaudi, 1992) in 1978, Coomans et al. opened the
way for a new identification of Conus desidiosus: Coomans et al. considered that Conus desidiosus
was a color form of a local population of Lautoconus guinaicus from
the Canary Island (Coomans et al., 1985). Now we know that this
indication was incorrect: as a matter of fact, in 1993, Lauer pointed out that the specimens described by
Saunders were actually Lautoconus guanche. ·
COOMANS H.E., MOOLENBEEK R.G., WILS E., 1985.
“Alphabetic
revision of the (sub)species in recent Conidae, 8 : dactylosus to dux”.
Basteria, 49 : 145-196 ·
SAUNDERS G.D., 1978. “A speculation upon C.
guinaicus Hwass, 1792. A species or a complex?”. La conchiglia, 10,
106-107:(16-18). ·
LAUER
J.M., 1993. “Description
of a new species and a new subspecies of Conus (Mollusca :
Prosobranchia : Conidae) from The Canary Island”, APEX 8(1-2): 37-50, march
1993. ·
LAUER J.M., 1993.“Conus
cacao Ferrario, 1983, taxonominal ad systematic context„, APEX 8(3):
115-127, juillet 1993 |
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Fig. 6 - (1-4): Conus cf.
guinaicus described by Saunders in 1978 – Lanzarote (Is. Canarie) Fig. 6 – (5): Conus desidiosus According to Lauer, these specimens are actually Conus guanche |
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1980-1992 |
Lautoconus ventricosus Lampedusa |
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The
new interpretation, however incorrect, had however indicated how Conus
desidiosus could be indicated as part of the complex of Lautoconus
ventricosus, and so it has been considered by several authors, among
which Roeckel et. al. in 1980 and Raybaudi in 1992. Raybaudi
stands out among all: she was convinced that some specimens of a local population of Lautoconus
cf. ventricosus from Lampedusa coincided almost perfectly with the
lectotype of Conilithes desidiosus, so she indicated them as specimens
of Conus desidiosus, or more exactly Conus ventricosus var.
desidiosus, and varied the typical locality from West Africa to Lampedusa
(Raybaudi, 1992). The same idea was subsequently followed by Lauer in march
1993, but he changed his mind in july 1993. ·
ROECKEL
D., 1981. “Conus mediterraneus or Conus ventricosus?”, La
conchiglia, Roma, N. 144-145 : 21-23
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International
Shell Magazine, 23(263), 10-15. ·
LAUER J.M., 1993. “Description
of a new species and a new subspecies of Conus (Mollusca :
Prosobranchia : Conidae) from The Canary Island”, APEX 8(1-2): 37-50, march
1993. ·
LAUER J.M., 1993.“Conus
cacao Ferrario, 1983, taxonominal ad systematic context„, APEX 8(3):
115-127, juillet 1993 |
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Fig. 7 - Conus
from Lampedusa (Raybaudi, 1992) |
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Fig.
8 – Conus ventricosus var. desidiosus 27,4 mm Lampedusa Island, Italy (coll. Lauer) |
Fig. 9 – Conus ventricosus var. desidiosus Lampedusa Coll.
Nappo |
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Altre
varietà di Lautoconus ventricosus che potrebbero essere simili al
Conus desidiosus |
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1996-today |
Also
Monteiro, Tenorio and Poppe was inclined to accept this idea, with reference
to some specimens from Portugal, but while Raybaudi states that not all the
specimens of Conus ventricosus from Portugal are Conilithes
desidiosus, Tenorio maintains that it is not certain that the population
from Lampedusa is composed of specimens of Conus desidiosus (Monnier
& Tenorio). Both
theses have some basis of truth and wrong, as Raybaudi, Monteiro and Tenorio
refer to two different populations related to Lautoconus ventricosus,
very different from Conilithes desidiosus. This
last hypothesis has been followed by numerous traders, who have indicated as Conus
desidiosus many specimens that in reality are only varieties of Conus
ventricosus ·
MONTEIRO
A., TENORIO M. J., POPPE G. T., 2004. “The
family Conidae – The West African and
Mediterranean Species of Conus” |
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Conus ventricosus
mm. 25,7 x 14,2 Portogallo – Olhao -
Algarve Maggio 2015 [AZRC 547-58] |
Conus ventricosus
mm. 22,6 x 11,2 Croazia - 2003 [AZRC N. 547-16] |
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Conus ventricosus mm. 28,8 x 12,6 Tyros - Grecia [AZRC N. 286-01]
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Conus ventricosus mm. 27,6 x 16,2 Tyros – Grecia [AZRC 547-51] |
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Confronto
tra Lautoconus ventricosus e Conus desidiosus |
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