Contribution to the knowledge of the family Caecidae. 1. A new Caecum from Canary Islands (Caenogastropoda: Rissooidea)

4 Pages·1994·1.5 MB·English

PIZZINI,NOFRONI & OLIVERIO AnewCaecum APEX 9(2/3): 79-82,juillet 1994
Contribution to the knowledge of the family Caecidae.
1. A new Caecum from Canary Islands
(Caenogastropoda: Rissooidea) *
Mauro PIZZINI
Largo délia Cafifarelletta 6. 1-00179 Roma, Italia,
NOFRONI
Italo
Via Benedetto Croce 97. 1-00142 Roma. Italia.
Marco OLIVERIO
Dipartimento di Biologia Animale e dell'Uomo, Université di Roma "La Sapienza".
Viale dell'Università 32. 1-00185 Roma. Italia.
ABSTRACT A \er> peculiar. new species ofthe meiobenthic gastropod family Caecidae
is described and figured from the Canary Islands: Caecum lightfootae n.sp. It is
compared with ail the known congencric species from this area.
KEYWORDS: Caecum, new species, meiobenthic, North-East Atlantic. Récent, marine.
INTRODUCTION SYSTEMATICS
The Caecidae are a worldwide distributed Superfamily RISSOOIDEA
family ofrissooidean gastropods with secondar> GrayJ.E.. 1847
uncoiled teleoconch, adapted to the meiobenthic Family CAECIDAE Gray ME.. 1850
life Despite a good deal of efforts, past and Genus Caecum Fleming. 1813
récents, to the study of their ta.xonomy (see i.e.
De Folin 1867-1876. 1867. 1875. 1880:
Carpenter 1858-1859; MooRE 1962, Van' Caecum lightfootae n sp
Aartsen 1977; LiGHTFOOT 1992a. b. c. 1993a. DESCRIPTION (hoIot\pe's measurements
b). Caecidae are still one of the less-known between parenthèses
)
prosobranch family The use of classical Teleoconch uncoiled. tube-like. Shell very
morpholog) in their ta.xonomy is often smali for the genus. semitransparent. glossy.
hampered by the difficult> in individuating Tube ver> curved. regularly bent. slightly
good characters in their simple, unusua! tube- subconical for one third of the length (on the
like shells. Even worse is the situation as for septum side), then nearly cylindrical for the rest
their supraspecific classification. Anatomical (Figs. 1. 2). Surface seemingly smooth, with a
data-sets are still poor and insufficient to create microsculpture of only thin and irregular
a good phylogenetic scheme ofthe family. growth Unes. Aperture regularly circular. with a
A
revision of the North-East Atlantic more or less pronounced varix, always présent
members ofthe family. presently in progress by (Fig. 3). Septum not retracted. with the latéral
the authors, is revealmg some important outline subtriangular and blunt. Mucro
novelties as for their taxonomy. Preliminar\ to protruding. and right-handed when obser\'ed
this revision, some still undescribed species frontally (Figs. 4. 5). Protoconch and growth
need tobe presented. stages not identified amidst the available
Working on some samples from the Canar\' material. Shell whitish, with irregular
Islands. a ver\' peculiar species of Caecum was
sorted out. It is a new species. différent from ail * Work partly supported by CNR (Comitato
the otherspecies known from thatarea. Ambiente) funds.
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APHX 9(2/3): 79-82,juillet 1994 AnewCaecum PIZZINI, NOFRONI&OLIVERIO
wax-vitreous areas Operculum thin. corneous. trachea (Montagu, 1805), C. glabrum
yellow-brownish; external surface with 4-5 (Montagu. 1803), C. vitreum Carpenter, 1858
concentrical ridges. the central and the outer and C. elegantissimum Carpenter, 1858.
part sniooth. Soft parts not studied at présent E\identl>. they skipped C. clarkii Carpenter,
mm
Dimensions: lenght 1.15-1.30 (1.23); tube 1858, though its type locality was just Is.
mm
diameter at the septum le\el 0.24-0.26 Tenerife. To this list a seventh species should be
(0.25); tube diameter at the aperture 0.34-0.36 added, namely C. armohcum De Folin, 1869
mm (0.35). recenth recorded by Hoeksema & Segers
(1993: 86) for the Canar>' Islands (Gran
Material examined: Punta Blanca. Puerto Canaria).
Santiago (Is. Tenerife. Canar\ Islands) - 30 m. C. lightfootae has a septum similar to that
M.Oliverio leg. 12-IX-1992: 28 shells. Arigana of C. clarkii and C.vitreum. It diflfers by its
(Is Gran Canaria. Canar>' Islands) - 1 m. smaller size. by the lack of a longitudinal
F.Gubbioli leg.: 1 spécimen. sculpture more (clarkii) or less (vitreum)
The t>pe material. ail from the t>pe localit} e\ident. by the présence ofthe annular vari.x at
has the following location: the aperture. and finally by its pronounced
Holot>pe and one parat>pe Museo Civico di cur\ature
Zoologia. Roma C. glabrum and C. armoricum are easily
2 parat>pes Laboratorio di Malacologia. separable from the new species by a différent
Université di Bologna septum (dome-shaped in the first, and nail-
2 parat>pes Muséum National d'Histoire shaped in the second), and by their lack of an
Naturelle, Paris apertural vari.x.
2 parat>pes Natural Histor\ Muséum. C. atlantidis, C. trachea and C.
London elegantissimum are completeh différent and
2 parat\pes Florida Muséum Natural unrelated species, with an e\ident annular
Histor). Gainsville sculpture, completely absent in C. lightfootae.
2 parat>pes Australian Muséum. S>dney A further european species, namely C.
2 parat>pes Swedish Muséum of Natural auriculatum De Folin, 1868 (whose t>pe séries
Histor\. Stockholm \\e ha\e studied), needs a brief comparison,
2 parat>pes Museo Insular Ciencias although it is not recorded for the Canarv
Naturales. Sla Cruz de Tenerife Islands. Its septum is nearly hemisphenc, with a
Other paratypes are stored in the private mucro hear-like, usually right-handed; the
collection of M. Pizzini (2). I. Nofroni (2). M. colour is uniformly white vitreous. Finally, C.
Oliverio (2). C. Schander (2). L, Trmgali (2). auriculatum is more curved, has a larger mean
G. Ambrosiano (I), F Gubbioli (1) size. and the apertural varix is more évident
than in C. lightfootae.
Type locality Punta Blanca, Puerto Santiago,
Is. Tenerife, Canar\ Islands (Spain). At présent
the species is knoun only from Canar\ Islands, Acknowledgements. We are gratefiil to Dr.
Is. Tenerife and Is. Gran Canaria. Chnstoffer Schander (Universit> of Gôteborg,
Sweden) for the numerous (too much!) SEM
Etymologv The species is dedicated to a \er\ pictures he realized for us.
keen american malacologist: the late Mrs.
Joanne Lightfoot. known to the spccialists of
this family for her studies on the Caecidae of
North America. The first aulhor had the
possibility to appreciate her scientific and
human endowments, during a short but intense
mail correspondence.
Figs. 1-5 (opposite).
Discussion. Although the morphological Caecum lightfootae n.sp. holotype. Is.
C
features of lightfootae are so peculiar to Tenerife.
render it unie and easily separable from an\ 1 General view (frontal).
other Canaric Caecidae, \ve prefer to compare it 2. General view (latéral).
with ail the other species known from this area. 3. Aperture.
NORDSIECK & T.ALA\ER.A (1979: 84) 4. Apex (frontal view).
recorded only fi\e Caecum species from the 5. Apex (latéral view).
Canan Islands: C. atlantidis Watson. 1897. C.
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PIZZINI, NOFRONl &OLIVERIO A ne\\ Caecum APEX 9(2/3): 79-82,juillet 1994
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APEX 9(2/3): 79-82.juillet 1994 Anew Caecum PIZZINl, NOFRONI&OLIVERIO
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