Four new Euthria (Mollusca, Buccinidae) from the Cape Verde archipelago, with comments on the validity of the genus

13 Pages·2003·7.1 MB·English

by  Emilio Rolán

© im^
SociedadEspañola deMalacología Iberus,2\ (1): 115-127,
Four new Euthria (MoUusca, Buccinidae) from the Cape
Verde archipelago, with comments on the validity of the
genus
Cuatro nuevas Euthria (MoUusca, Buccinidae) del archipiélago de
Cabo Verde con comentarios sobre la validez del género
Emilio ROLAN* Antonio MONTEIRO** and Koen FRAUSSEN***
Recibidoel2-XII-2002.Aceptadoel22-1-2003
ABSTRACT
Four species, collected in the Cape Verde Islands, are described as new and assigned to
the genus Euthria M. E. Gray, 1830. The new species are compared with other taxa from
the Mediterranean Sea and the Cape Verde Archipelago. The genera Euthria, and Buccin-
ulum are compared and the significance of the differences between them is discussed,
leading to the conclusión that both genera are valid and should be kept separated.
RESUMEN
Se describen cuatro especies nuevas del género Euthria M. E. Gray, 1830 recogidas en
aguas circalitorales del archipiélago de Cabo Verde. Las nuevas especies son compara-
das con otros taxones congenéricos existentes en el Mediterráneo y en el propio archip-
iélago. Recientemente, el género Euthria, únicamente conocido del Atlántico oriental, ha
sido sinonimizado con Buccinulum, que posee especies en el Indo-Pacífico, por lo que se
comparan ambos géneros y se discute el valor de las diferencias entre ellos, considerando
finalmente que ambos son válidos, y deben mantenerse separados.
KEYWORDS:Euthria, Buccinulum, CapeVerdeArchipelago, newtaxa.
PALABRAS CLAVE:Euthria, Buccinulum,vVrchipiélagodeCaboVerde, nuevostáxones.
INTRODUCTION
Ehiring the last few years, the genus them sepárate, as commented upen in
Euthria Gray, 1850 has frequently been "Remarks" ofthispaper.
considered as a synonym of Buccinulum The genus Euthria is represented in
Deshayes, 1830 (Beets, 1985, Sabelli, the Mediterranean Sea by a single
GiANNUZZI-SaVELLI AND Bedulli, 1990, species, Euthria cornea (Linné, 1758),
PoppE AND Goto, 1991, Bouchet, Le which is rather variable. On the con-
Renard and Gofas, 2001, Chiarelli, trary, several species have been
2002), but regarding the differences described, by Dautzenberg and
betweenbothgenerawesuggesttokeep FiscHER (1906), CosEL (1982b), Cosel
*CánovasdelCastillo, 22-5°F, 36202Vigo, España,[email protected]
**LargodaPrincesa24-l°E, 1400-303Lisboa, Portugal, [email protected]
***Leuvensestraat25, B-3200Aarschot, Belgium,[email protected]
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Iberus, 21 (1), 2003
Figure 1. Euthriasaharica. Originalrepresentación oftheholotype (fromLOCARD, 1897).
Figura 1. Euthriasaharica. Representaciónoriginaldelholotipo (deLoCARD, 1897).
AND BuRNAY (1983) and Rolan (1985), belonging to this genus that do not
for the Cape Verde Archipelago, and a match the ones previously known for
revisión of the genus has been pub- the archipelago and identify them as E.
lishedbyRolan (1987). cf. saharica and E. cornea. Rolan (in
In addition to the species from the press), in a review of the Cape Verde
Mediterranean and from Cape Verde, gastropod fauna, mentions these refer-
LocARD (1897) has described Euthria ences, but states that it is unlikely that
saharica (Fig. 1), Marche-Marchard theproposedidentificationsarecorrect.
AND Brebion (1977) have described Thepresentpaperisbased onmater-
Euthriostoma gliberti, both from the ial obtained during the lastfewyearsby
western coast of África. These species César Fernandes. This materialhasbeen
have a more fusiform shell, with an dredged from deep waters in different
elongated siphonal channel, that it is we pointsoftheArchipelago.
consider it doubtful that they belong to
the genus Euthria at all. Bouchet and Abbreviations:
Warén (1986) have placed these species MNCN Museo Nacional de Ciencias
in synonym together with Metzgeria Naturales,Madrid
apodema BouchetandTalavera 1981, con- CCF collection of César Fernandes,
sidering it is not an Euthria. Guerreiro Cascáis
AND Reiner (2000) show some shells CERcollectionofE. Rolan,Vigo
SYSTEMATICS
Genus Euthria M. E. Gray, 1850
Type species: Buccinum corneum Linné, 1758. Recent, Mediterranean. Original designation:
"Fusus lignarius Chiaje" (this is Fusus lignarius Lamarck, 1816, a júnior synonym ofMurex
corneasLinnaeus,1758).
Description: Gray (1850): 'Teeth, Muzzle rectactile. Operculum annular.
central 1 large, lateral 1-1, versatile. Siphon ofmantle produced in front" for
116
Rolan ETAL.: NewEuthriafrom CapeVerde, with comments on the genus
the family; "Operculum ovate, acute; The radulae of Siphonofusus Kuroda
nucleus apical. Varices ofshellrudimen- AND Habe, 1954 and Afrocominella
tary or none" for the group to which Iredale, 1918 are similar too, but differ
belong; and, finally "Canalelongate" for by the quadrangular middle tooth with
the genus. Tríele (1935): "Shell spindle- rather sharp corners (Cooke, 1917,
shaped, with high, ribbed spire; aper- Barnard, 1959).
tureoval; canalinmostcasesfairlylong, The type species of Buccinulum {B.
somewhat oblique. Operculum with ter- lineum Martyn, 1784) (Figs. 29-31), and
nünalnucleus". consequently other Pacific species
Remarks: All Recent Euthria species included in the same genus, doubtlessly
have a more or less conspicuous subsu- have a certain morphological resem-
tural depression or concavity (E. rolani blance to the Atlantic species of Euthria.
von Cosel, 1982, ornamented with a Conchological differences between
thick and rather bulbous suture, being Euthria and Buccinulum are rather slight,
an exception); they have some axial but we must recognize the presence of
sculpture on the upper whorls, and lack somewhat prominent axial ribs on the
well developped spiral sculpture but upper whorls and a clear subsutural
occasionally show some fine cords or concavity in Euthria. The material of
striae (the only exception being E. which the shell of Buccinulum is pro-
effendyi [see Fraussen, 2002] - of which duced will be an interesting matter for
we have no radula available - to ensure further study, as the surface is not as
the generic placement, an Indonesian smoothandbrilliantasinEuthria,which
species which is closely related to the is rather glossy, especially in the Indo-
fossilfauna). WestPacific.
The radula of Euthria, consisting of3 We agree with Beets (1986) to con-
teeth (1 middle, 2 lateral) with each 3 sider the Indonesian archipelago as the
cusps, is typical for Buccinidae. The geological center of Buccinulum and
form of the middle tooth (triangular Euthria. In the Recent fauna we can rec-
with the cusps on the broad upper ognize 4 important geographical áreas:
córner) (Iredale 1917, Cooke 1917, the important radiation of Buccinulum
Shuto 1978, Rolan 1987), is shared around New Zealand (differentiated
with Euthriostoma Marche-Marchard from typical Euthria already early in
and Brebion, 1977 (Fraussen, unpub- history during the Tethys Sea), an
hshed) and Afer Conrad, 1858 Euthria radiation along the coasts of the
(FraussenandHadorn 1999). Indian Ocean, another on the lower
The radula of Buccinulum is similar shelf around New Caledonia and,
in general aspects but differsby a some- finally, the East Atlantic Euthria -
what broader, lesser triangular central Euthriostoma - Afer radiation (separated
tooth with more rounded margins from the main group during the split of
(Cooke 1917). Wecanbasethiscompari- theTethysSea). Thespecies described as
son on a limited number ofspecies only, newinthepresentpaperareanaddition
as a more thoroughfull study of the tothislattergroup.
radula of all New Zealand species is Regarding the difference in radula,
beyond the limit of the present paper. geographic-geological separation and a
Further study probably can bring more number of slight conchological differ-
light on the eventual presence ofEuthria ences cited above, we consider the
species among the buccinulums ofNew genera Euthria and Buccinulum as being
Zealand. differentandkeepthemsepárate.
Euthria soniae spec. nov. (Figs. 2-7, 23B, 25A, 28E)
TypeMaterial:Holotype(Figs.2-4)inMNCN(15.05/46582).Paratypesin:CCF(1,Fig.5),CER(1,
Fig.6),MNHN(l,Fig.7).
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Iberus, 21 (1), 2003
Figures 2-7. Euthria soniae. 2-4: Holotype, 53.3 mm, Cape Verde archipelago (MNCN); 5:
Paratype, 46.3mm (CCF). 6: Paratype,47.2mm (CER). 7: Paratype, 50.2mm (MNHN).
Figuras2-7. Euthria soniae. 2-4: Holotipo, 53,3 mm, archipiélago de Cabo Verde (MNCN); 5:
Paratipo, 46,3mm (CCF). 6:Paratipo, 47,2mm (CER). 7:Paratipo, 50,2mm (MNHN).
118
Rolan ETAL.-. NewEuthriafrom CapeVerde, with comments on the genus
Figures 8-12. Euthria marianae. 8-10: Holorype, 36.9 mm, between SaoVicente andSao Nicolau,
CV (MNCN). 11: Paratype, 33.4 mm (CCF). 12: Paratype, 35.3 mm (CER). Figures 13-15.
Euthriacf. marianae. Concha, 34.0 mm, betweenSaoVicenteandSaoNicolau, CV (CCF).
Figuras 8-12. Euthria marianae. 8-10: Holotipo, 36,9 mm, entre Sao Vicentey Sao Nicolau, CV
(MNCN). 11: Paratipo, 33,4mm (CCF). 12: Paratipo, 35,3 mm (CER). Figuras 13-15. Euthriacf.
marianae. Concha, 34.0mm, entreSao VicenteySaoNicolau, CV(CCF).
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Iberus, 21 (1), 2003
Typelocality:CapeVerdeArchipelago.ThetypematerialwasdonatedbyCapeverdianfishermen
withoutexactinformation.Itishoweverlikelythatitwascapturedin"barlavento"groupofislands.
Derivationominis:ThenewspeciesisnamedafterbiologistSoniaElsyMerino,whohasdedicated
herselftothestudyandconservationofthemarinefauna,workinginPortoMindelo,SaoVicente,
CapeVerdeArchipelago,andwhohascooperatedwithourresearch.
Description: Shell (Figs. 2-7) ovoid- Softpartsunknown.
fusiformand solid. The protoconch (Fig. Distribution área: The species is
23B, 25A, 28E) is yellowish, with 1 V4 - known only from theCapeVerdeArchi-
2 spiral whorls and a diameter of about pelago. The short protoconch suggests
1.7 mm. Teleoconch with 7 rapidly aninsularendemisn\.
increasing whorls. The whole spire pre- Comparison: The present species
sents axial ribs, 9 - 10 in number on first mustbe compared with E. cornea, which
whorl, 10-12 on last whorl. Subsutural has a similar profile, but is sometimes
ramp strongly depressed. Aperture larger, [easily up to 65 mm, but also
mm
ovoid, white, with 12-13 internal folds larger: 84,7 in F. Pusateri coUection,
visible at the internal part of the peris- Palermo, and Settepassi (1971) records
tome; it is continued with a narrow and the máximum size known at 88 mm]. E.
slightly curved siphonal canal. Yellow- cornea has axial nodules on the first 4-5
ishtobrownundulatedaxialflammules, spiralwhorls, rarelyon thelastone. The
sometimescoalescing,and evenforming main difference is the protoconch,
a reticulated pattern, appear on a white which in E. cornea (Figs. 23A, 28A) has a
background. little more than 1 whorl, with about 0.8
Holotype 53.3 mm x 21.1 mm. The mm, and in E. soniae (Fig. 23B, 28E) has
paratypes areslightlysmaller, thesmall- between 1^/4 and 2 whorls, with about
mm mm
estonebeing46.3 long. 1.7 ofdiameter.
Euthria marianae spec. nov. (Figs. 8-12, 24B, 28C)
Typematerial:Holotype(Figs.8-10)inMNCN(15.05/46583).Paratypesin:CCF(1,Fig. 11),CER
(1,Fig. 12).
Typelocality: BetweenSaoNicolauandSaoVicente,atadepthof75-150m,intheCapeVerde
Archipelago.
Derivationominis:ThenewspeciesisnamedafterMariana,thegranddaughterofCésarFernan-
des-awell-knownPortuguesecollectorwhohasgreatlycontributedtotheknowledgeofthemala-
cologicalfaunasoftheCapeVerdeIslandsandofMozambique-andthedaughterofCésarFer-
nandesJr.,akeendiverandshellhunter.
Description: Shell (Figs. 8-12) ovoid- brown band with white blotches on the
fusiform and solid. The protoconch last whorl; this band is visible on previ-
(Figs. 24B, 28C) is pink, with between 1 ous whorls on a shortparton thesupra-
^/4 and 2 spiral whorls and a diameter suturalárea.
ofabout 1.5 mm. Teleoconch with about The holotype mesures 36.9 x 19.1
6 rapidly increasing spiral whorls, with mm. Theparatypesareofsimilarsize.
weak undulating axial ribs, present on Softpartsunknown.
the whole shell, 11 on the firstwhorl, 16 Distribution área: The species is
on the last whorl. Subsutural ramp known only from locations between S.
m
slightly depressed, suture nodulous. Nicolau e S. Vicente, at 75 - 150 of
Aperture ovoid, white, with about 11 water,takenfromtraps.
teethininnerpart, continuedwithinter- The short protoconch suggests an
nal folds; the aperture extends into a insularendemism.
narrow, elongated and curved siphonal Comparison: Thepresentspeciesmust
canal. Background colour white, with a be compared with E. rolani Cosel, 1982
120
RolAn ETAL.: NewEuthriafrom CapeVerde, with comments on the genus
and E. boavistensis Cosel, 1982, which withwideblotches,andtheprotoconchis
have similar aspects. E. rolani was col- wider and dark brown (Figs. 24A, 27,
mm
lectednearSantaLuziainshallowwater, 28B),about2.1 indiameter. E. boavis-
and the shell is more globose and solid, tensishasasmallershell,withadifferent,
the aperture is pink-violet instead of more irregular, colour pattern, the aper-
white, the subsutural área is not ture constantly pink and the protoconch
mm
depressed,thecolourpatternisdifferent. alittlesmaller(about1.2 diameter).
Euthriafemandesi spec. nov. (Figs. 16-18, 28B, 28D)
MNCN
Typematerial:Holotype(Figs. 16-18)depositedin (15.05/46584).
Typelocality:DredgedbetweentheislandsofMaioandBoavista,at75-125m.CapeVerdeArch-
ipelago.
Derivationominis:Thenewspeciesisnamedafterthewell-knownPortugueseshellcoUectorCésar
Femandes.
Description: Shell (Figs. 16-18) ovoid- E.femandesi spec. nov. mustbe com-
fusiform and solid. The protoconch pared with E. cornea, and it may be sep-
(Figs. 25B, 28D) is white, with a little arated because the latter species does
more than 2 spiral whorls and a diame- not have the conspicuous coloured
terof2.2 mm. Teleoconchwith 6 rapidly bands, and the last whorls usually lack
increasing spiral whorls, with axial ribs axial and spiral sculpture. Furthermore,
onthewhole shell, 10 onthefirstwhorl, the protoconch has only one whorl, it is
16 on the last whorl; these ribs are cream or light brown, and its diameter
mm
present at the suture, giving it a nodu- is smaller (only 0.8 in diameter,
mm
lous aspect. Subsutural ramp strongly versus2.1 inthenewspecies).
depressed. Aperture ovoid, white, with E. calypsoCoselandBurnay, 1983has
13 folds on its outer lip; the aperture asimilarsize,buttheshellpatternisdif-
extends into a narrow, slightly elon- ferent, with spiral blotches only, more
gated and dorsally curved siphonal evident on the suture, and lacking axial
canal. The background colour is irregu- sculpture, except in the first whorls of
lar light brown, with numerous small the teleoconch. Its spiral sculpture is
axial white Unes; there is a suprasutural formed by spiral threads, which are
broad dark brown spiral band, inter- evident on the first whorls only, and the
rupted by white blotches, and other subsutural depression is less evident.
similar but less conspicuous bands Thewhorlsarelessconvex.
towardstheanteriorendoftheshell. E. pulicaria Dautzenberg and Fischer,
Theholotypeis51.3mmx22.6mm. 1906 has a smaller, less elongated shell,
Softpartsunknown. with a small subsutural depression but
Distributionárea: The speciesis only prominent suture, a different colour
knownfromthetypelocality patternandasmallersiphonalcanal.
The short protoconch suggests an E. soniaespec. nov. lacks spiralsculp-
insularendemism. ture, has a more elongated spire, the
Comparison: Only the holotype is colour pattern is formed by axial flam-
available, but we decide to describe this mules without any spiral banding, and
species, because of important differ- the protoconch is smaller and yellowish
enceswithothercongenericspecies. (insteadofwhite).
Euthria helenae spec. nov. (Figs. 19-22, 26, 28F)
Typematerial:Holotype(Figs.19-21)inMNCN(15.05/46585).Paratypesin:CCF(1,Fig.22),CER(1).
Typelocality:BetweenSaoNicolauandSaoVicente,at75-125mdepth.CapeVerdeArchipelago.
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Iberus, 21 (1), 2003
Figures 16-18. Euthriafernandesi. Holotype, 51.3 mm, between SaoNicolauandSaoVicente, CV
(MNCN). Figures 19-22. Euthria helenae. 19-21: Holotype, 40.2 mm, between Sao Nicolau and
SaoVicente, CV(MNCN); 22: Paratype, 25.4mm, (CCF).
Figuras 16-18. Euthria fernandesi. Holotipo, 51,3 mm, entre Sao Nicolauy Sao Vicente, CV
(MNCN). Figuras 19-22. Euthria helenae. 19-21: Holotipo, 40,2 mm, entre Sao Nicolauy Sao
Vicente, CV(MNCN);22:Paratipo, 25,4mm, (CCF).
122
Rolan ETAL.: NewEuthriafrom CapeVerde, with comments on the genus
Figures 23-28. Comparison at same magnification between the protoconchs oíE. cornea (A) and
E. soniae(B); 24: Comparisonatsamemagnification betweentheprotoconchsof^. rolani(A) and
E. marianae (B); 25: Comparison atsame magnification between the protoconchs oíE. soniae (A)
and E.fernandesi (B); 26: Protoconch oíE. helenae; 27: Larval shells of^. rolanibefore hatching;
28: Comparison at same magnification between theprotoconchs oíE. cornea (A), E. rolani (B), E.
marianae(C), E.fernandesi(D),E. soniae(E) andE. helenae(F).
Figuras23-28. Comparación almismo aumento entre lasprotoconchas de E. cornea (A)y E. soniae
(B); 24: Comparación almismo aumento entre lasprotoconchas de E. rolani (A)y E. marianae (B);
25: Comparación almismo aumento entre lasprotoconchasde E. soniae (A)yE. fernandesi (B); 26:
ProtoconchadeE. helenae;27: ConchaslarvariasdeE. rolani antesdelaeclosión;28: Comparaciónal
mismoaumentoentreUsprotoconchasdeE. cornea (A), E. rolani (B), E. marianae (C), E. fernandesi
(D), E. soniae (E)yE. helenae (F).
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Iberus, 21 (1), 2003
Figures 29-31. Buccinulum lineum, 35.5 mm, NewZealand (CER). Figures 32-36. Euthriacornea.
32: Shell, 51.2 mm, Faro, Algarve, Portugal (CER); 33: Shell, 50.6 mm, Cabo de Palos, Murcia,
Spain (CER); 34: Shell, 37.9 mm, Malta (CER); 35; Shell, 54.7 mm, Sokakagzi, Turkey, 125 m
(CER); 36: Shell, 29.2 mm, KaraadeIsland, SouthofBofrum,Turkey(CER).
Figuras29-31. Buccinulum lineum, 35,5 mm, NuevaZelanda (CER). Figuras32-36. Euthria
cornea. 32: Concha, 51,2mm, Faro,Algarve, Portugal(CER);33: Concha, 50,6mm, CabodePalos,
Murcia, Spain (CER); 34: Concha, 37,9 mm, Malta (CER); 35: Concha, 54,7mm, Sokakagzi,
Turquia, 125m (CER);36: Concha, 29,2mm, islaKaraade, surdeBofrum, Turquia (CER).
124