Question sur Conus maldivus

Existe-t-il une différence patente entre Conus generalis f. maldivis et Conus maldivus?

Conus  maldivus   Hwass in Bruguiere,  1792

Picture Link: Lectotype in MHNG Mike Filmer
Picture Link: Paul Kersten
Radula Picture: Manuel Tenorio

Published in: Encyc. Meth. Hist. Nat. des Vers. Vol. 1,  p. 644
Ocean geography: Indo-Pacific
Type Locality: Maldive Islands
Type Data: Lectotype in MHNG deposited and catalogued
Type Size: 63 x 31 mm
Nomenclature: An available name
Taxonomy: A valid species
Current Group Names:-
Family:-CONIDAE SubFamily:-PUNCTICULIINAE
Genus:-Strategoconus Species:-maldivus
Synonyms:- dux Röding, 1798; filosus Röding, 1798; jaspideus Swainson, 1822; spirogloxus Deshayes, 1863; planaxis Deshayes, 1863; monteiroi Barros e Cunha, 1933
Geographic Range:-Mozambique to Red Sea and to S. India
Habitat:-Slightly subtidal to about 6 m on reefs and coastal flats, in sand, sandy gravel or rubble, sometimes beneath coral blocks among weed
Description:-Source Living Conidae
Medium-sized to large, solid to moderately heavy. Last whorl conical to narrowly conical, outline variably convex adapically and straight below. Shoulder angulate. Spire of low to moderate height, outline deeply concave to almost straight, with a conoid apex of about 7-8 postnuclear whorls projecting from an otherwise nearly flat spire. Maximum diameter of larval shell about 0.75 mm. First 7 postnuclear whorls weakly tuberculate. Teleoconch sutural ramps flat to concave, with obsolete spiral striae in late whorls. Last whorl with fine spiral ribs at base, obsolete in larger specimens.
Ground colour white. Last whorl with 2 broad light to dark brown spiral bands, either solid or split into axial streaks, flames, blotches or bands, leaving ground-colour zones at shoulder, at or below centre and near base. White subshoulder band narrow, usually crossed by axial extensions of adapical colour band. White central band variable in width, almost immaculate to heavily maculated with extensions of colour bands, occasionally completely absent. White abapical zone broad or narrow, sparsely to heavily maculated with brown. Minutely dotted to largely solid brown spiral lines extend from base to shoulder but vary widely in number and arrangement; occasionally, spiral lines partly interrupted by white dots and sparse, small white tents. Base dark brown to violet-brown. Larval whorls pink. Early postnuclear sutural ramps immaculate; late ramps with curved brown radial markings. Aperture white.
Shell Morphometry
L 50-83 mm
RW 0.30-1.06 g/mm
(L 50-80 mm)
RD 0.48-0.62
PMD 0.85-0.92
RSH 0.03-0.18
Discussion:-C. maldivus is very similar to C. generalis and cannot always be unequivocally separated from this species by conchological characters. The only reliable difference is in the colour pattern: In C. generalis, the basic pattern consists of 2 spiral colour bands that are usually solid and rarely split into axial fragments, and that cross underlying darker axial streaks or flames extending over the entire last whorl; the adapical ground-colour band is usually broader and the dark spiral lines rarely consist of minute dots or become solid. C. maldivus occurs with C. generalis form krabiensis at Mandapam, S. India, without producing conchological intermediates (Röckel, 1989). RKK therefore consider them as separate species.
The shells of C. capreolus are lighter than those of C. maldivus, the bases are white, late postnuclear whorls are carinate and lack radial markings, and darker spiral lines are absent from their last whorl.
C. planaxis and C. spirogloxus refer to juvenile specimens assigned to C. maldivus mainly on account of their type localities.

Bernard

Je ne connais pas cette forme maldivis !

A mon avis la meilleure séparation est dans les zones de répartition.
Evidemment il y a des zones ou il y a chevauchement... mais pas tant que cela !


RKK page 176

C'est vrai que ce n'est pas facile...

Toujours le RKK :

"Discussion: C. maldivus is very similar to C. generalis and cannot always be unequivocally separated from this species by conchological characters. The only reliable difference is in the colour pattern: In C. generalis, the basic pattern consists of 2 spiral colour bands that are usually solid and rarely split into axial fragments, and that cross underlying darker axial streaks or flames extending over the entire last whorl; the adapical ground-colour band is usually broader and the dark spiral lines rarely consist of minute dots or become solid. C. maldivus occurs with C. generalis form krabiensis at Mandapam, S. India, without producing conchological intermediates (Röckel, 1989). We therefore consider them as separate species. "

Effectivement je ne connaissais pas cette f maldivis.... Je l' ai trouvée sur le taxa qui accompagnait un Conus maldivus avec un dessin différent (Merci Dam's!). je vous poste des photos dès que je peux.
Malakos donne une photos qui n' est en rien ce que j' ai reçu et qui pour moi est un C. maldivus:
http://www.malakos.org/Sis/Conidae/C_generalis.html

generalis et maldivus sont bien deux espèces différentes. Des analyses ADN ont été réalisées et confirme cette différence.
Ce site malakos fait une erreur majeure en considérant maldivus comme une forme.
A mon sens et compte tenu des aires de répartition, il n'est pas si difficile de différentier les deux espèces.

Et le WoRMS aussi alors
http://www.marinespecies.org/aphia.php?p=taxdetails&id=215539

Le WoRMS raconte beaucoup de c...

C'est bien de me le faire remarquer.
Je vais envoyer un mail à Philippe BOUCHET; d'autant plus que c'est son laboratoire qui a fait les analyses...
La publication est prévue dans les mois qui viennent.