A new Anachis (Gastropoda: Columbellidae) from Gabon

2006·1.2 MB·

by  Emilio Rolán

E. ROLÂN& F. BOYER NOVAPEX 7(1): 25-27. 1 mars 2006
A new Anachis (Gastropoda: Columbellidae) from Gabon
ROLÂN
Emilio
Museo de Historia Natural, Campus Universitario Sur, 15782
Santiago de Compostela. Spain
emiliorolanfà inicia.es
BOYER
Franck
1 10 chemin du Marais du Souci, 93270 Sevran, France
KEY WORDS. Columbellidae. Anachis. Gabon, West Africa, new species.
ABSTRACT. A new species ofAnachis from Gabon is described. The species is compared with
other similar species ofthe genus from the West African coast.
INTRODUCTION Intercontinental Hôtel, Libreville, Gabon.
mm
Most of the infralittoral species of Columbellidae Description. Shell solid. (Figs. 1-4) up to 3.5 in
from Eastern Atlantic hâve been recently revised length, broadly fusiform with moderately high spire.
through several articles dealing with the Mitrella Protoconch (Figs. 5, 6) of2 %whorls, sharply pointed.
minor group (Boyer & Rolân, 2005). the fauna from about 400 um maximum diameter, first whorl smooth.
the Canary Islands (Hernândez & Boyer. 2005), the fine spiral cord at periphery oflast whorl; at the end,
fauna from Sénégal (Pelorce & Boyer, 2005), the subsutural sinus shows planktotrophic development;
fauna from the Cape Verde Islands (Rolân & Luque, colourdark brown, except when eroded.
2002, Rolân, 2001, 2004) and the fauna from the Gulf Teleoconch of 4-4 Vi scarcely convex spiral whorls,
ofGuinea (Rolân, 2005). with distinct suture and small subsutural shelfformed
More recently, spécimens of an unrecorded species by thick spiral cord forming nodules at the cross with
from Gabon were found. This species is described the axial ribs. Axial sculpture formed by ribs
hereafteras new. subsuturally well defined, between 14 and 15 on last
whorl. No spiral sculpture in interspaces ofribs. Seven
Abbreviations strong spiral cords close togetherat base oflast whorl.
Aperture narrow and axially elongated. usually dark
MNCN Museo Nacional de Ciencias Narurales. brown inside. Columellar border straight, only curved
:
Madrid, Spain. upperwards, with 4-6 very small folds in middle part.
MNHN: Muséum national d'Histoire naturelle, Paris. Along upper 2/3 of inner edge of labrum prominent
France. wide nodule and 2-3 very small denticles below. Outer
lip slightly thickened.
SYSTEMATICS Colour uniformly dark brown. Periostracum thin.
GenusAnachis H. Adams and A. Adams, 1853. smooth and transparent.
Type species Columbella scalarina G. B. Sowerby II, Soft parts, operculum and radula unknown.
1832, from Panama (Chiriqui) by subséquent
désignation (Tate, 1869). Distribution. Only known from the type material.
Diagnosis: Radwin(1977: 120).
Remarks. Anachis delemarrei spec. nov. differs from
Anachisdelemarreispec. nov. the other West African Anachis in its smaller size and
Figs 1-6 in its uniform dark colour.
The protoconch ofA. ryalli Rolân. 2005 from Ghana
Type material. Holotype (Figs 1-3) MNHN, Moll has less whorls. In this species. spiral cords occur
MNCN
9314. Paratypes: (1) n° 15.05/46694, between the axial ribs, and the labial teeth are more
collection E. Rolân (1). collection F. Boyer (1). uniformly sized.
collection J. L. Delemarre (2), collection M. Anachis avaroides Nordsieck. 1975. from the Canary
Lequément (1). collection P-H. Hattenberger (1). Islands and Selvagens. is larger (about 7 mm) and
collection J. Pelorce (1) and collection J. Hernândez wider, with a variable ground colour decorated with
(1). whitish marks and ocelles. Tiny spiral cords often
occur between the axial ribs in this species. It is
Type locality. Intertidal. under stones. in front ofthe
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I R<.1 \\ & I H«^ l R A new Anachis from Gabon
interpreted bj Hernàndez & Boyer (200S) as a ACKNOWLEDGEMENTS
possible stout and ribbed forra of Mitrella broderipi
(Sowerby, 1844). We thanks Jésus S. Troncoso for the optical
Unnhi\ valledoh Rolân cSL Luque, 2002 is ver> photographs made in the Department of Ecology of
variable in ground colour and décoration pattern, but the University ofVigo.
always larger (up to s mm). The protoconch is REFERENCES
paucispiral meaning direct development; the
teleoconch lias an évident spiral sculpture; the aperture Boyer, F. & Rolàn. E. 2005. About a sibling species of
au extemal lip bearing more uniform and smaller Mitrella minor(Scacchi, 1836). Iberus 23 (2): 53-
denticles.
67.
Anachis freytagi Malt/an. ISS4 [= Columbella Hernàndez, J.M. & Boyer, F. 2005. The
i [nachis) bubakensis Lamy, 1923] bas a larger(about Columbellidae from C'anary Islands. Iberus 23 (2):
7 mm) and relatively narrower shell. with a light tan 69-93.
(dark brown or blackish ground colour) and a variable Pelorce, J. & Boyer, F. 2005. La famille
décoration o( white marks; a narrovv aperture; a Columbellidae (Gastropoda: Muricoidea) dans
contracted base, tiny spiral cords often occurring l'infralittoral de la Péninsule du Cap Vert. Iberus
between the axial ribs. 23 (2): 95-1 18.
Anachis cuspidata Marrât, 1877 [= Pyrene (Anachis) Radwin, G.E. 1977. The family Columbellidae in the
emergens Fischer-Piette and Nicklès, 1946] has a Western Atlantic Part Ilb.- The Pyreninae
larger and wider shell with a pupoid protoconch. The (continued). The Veliger20 (4): 328-344.
ground colour goes from whitish to honey brown often Rolân, E. 2001. Mitrellaguerreiroi, a new species for
decorated with a dark check pattern. Cape Verde Islands. La Conchiglia 33 (301): 1 1-
Mitrella turbita (Duclos. 1840) (= Columbella rac
13.
Dautzenberg. 1891) is wider and larger (up to 8-9 Rolân, E. 2004. A new species more ofMitrella
mm), with wide and sinuous short axial ribs restricted (Neogastropoda, Columbellidae) from the Cape
to the upper part ofthe last whorl. It has a less pointed Verde Archipelago. La Conchiglia 36(311): 21-
protoconch and a light honey ground colour decorated
23.
with large white ocelles. Rolân, E. 2005. Columbellidae (Gastropoda,
Parvanachis aurantia (Lamarck, 1822) (= Columbella
Muricidae) ofthe Guinean Gulfwith the
cstarnocnegllantoaduGlaesskoionv.er18t5he1)wihsollaergesrhelaln.dTwhiederg,rowuintdh description of8 new species. Iberus 23 (2): 1 19-
156.
colour is light orange and the apex vitreous pinkish. Rolân, E. & Luque, A.A. 2002. Two new species of
Etymology. The species is named after J. L. Columbellidae (Gastropoda: Buccinoidea) from
Delemarre, French malacologist who collected the the Cape Verde Archipelago. Iberus 20 (1): 73-83.
type material. Tate, R. 1869. Appendix [to] S. P. Woodward,A
manualofthe Mol/usca, 2nd éd. separately paged
1-86; 27 text figs. London.
Figures
1-6.Anachis delemarrei spec. nov. 1-3. holotype, 3.5 mm (MNHN, Moll 9314); 4. paratype, 3.2 mm (MNCN);
mm
5-6. protoconch in two positions, paratype, 3.5 (collection E.Rolân).
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E. ROLÂN & F. BOYER Novapex 7(1): 25-27, 1 mars 2006
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