J. Moll. Stud. (2001), 67, 269–274 © The Malacological Society of London 2001

INTRODUCTION

Living specimens and empty shells of an unknownspecies of epitoniid gastropod have been recognized inthe course of study of molluscan samples collected inNovember 1995 during a malacological survey in theTuléar region (South-West Madagascar), within theframe of the European Community project TESTREEF 95 (TEmporal and SpaTial variability of west-ern Indian Ocean REEFs).

The species under study is quite distinct from anyother species of Epitonium Röding, 1798, by its verydistinctive teleoconch showing at low magnification aspirally lirate microsculpture only on the early whorls.As far as we know such a character is shared uniquelywith Epitonium (Sodaliscala) apiculatum Dall, 1889, arare species from North and South Carolina and Gulfof Mexico and in part with the Indo-West Pacific Epi-tonium costulatum (Kiener, 1838) which according toGittenberger et al. (2000) shows this microsculptureunder SEM examination. Our specimens and shells canbe distinguished from these species and, therefore, anew taxon is proposed.

SYSTEMATIC DESCRIPTION

Family Epitoniidae Berry S.S., 1810 (1812)

Genus Epitonium Röding, 1798: 91. Type species (s.d.Suter, 1913): Turbo scalaris Linnaeus, 1758

Epitonium (Asperiscala?) oliverioi new species

Figs. 1, 2

Diagnosis: shell pyramidal (breadth/length 0.43–0.54),teleoconch whorls convex, suture perforate, umbilicus

open, peristome thin, auriculate, axial ribs thin, erect,prosocline, lamellate, peaked, 19–20 on the bodywhorl. Early teleoconch whorls spirally lirate, sub-sequent whorls smooth. White. Maximum length 19mm.

Shell (Figs. 1A–C): pyramidal (breadth/length0.43–0.54) of about 9 convex teleoconch whorls sepa-rated by a deep perforate suture, umbilicus open, aper-ture ovate, peristome simple, auriculate. Axial ribsvariable in number, 19 on the body whorl of holotype,fewer on the penultimate whorl and in smaller speci-mens, high, thin, lamellate, prosocline, erect, slightlyoffset, with a shoulder coronation, hooked. Intervalsbetween axial ribs of the early four whorls with 10 spiral lirae (Fig. 1C), subsequent whorls smooth (Fig.1D). Colour white.

Protoconch (Figs. 1F–G): rather conical, of about 3convex whorls, translucent with very fine, slightly arcuate axial striae; diameter about 0.4 mm.

Operculum (Figs. 2A, B): paucispiral; under SEM mag-nification the external surface shows a minute threadpattern.

Radula (Figs. 2C, D): each row has several teeth (num-ber not determined) generally club shaped with a smallhook at the tip and which vary continuously in shapeand size from obtusely triangular to needle-like relativeto the development of their basal attachment to theradular membrane.

Spawn (Figs. 2E, G–I): a spawning female was col-lected under Fungia sp. (Fig. 2F). The spawn consistsof a 50 mm winding string of pyramidal capsules

EPITONIUM (ASPERISCALA ?) OLIVERIOI, A NEW SPECIES OFEPITONIIDAE (GASTROPODA) FROM MADAGASCAR.

ANTONIO BONFITTO AND BRUNO SABELLIDipartimento di Biologia evoluzionistica sperimentale - Museo di Zoologia via Selmi 3, 40126 BOLOGNA, ITALY

bonfitto@alma.unibo.it sabelli@alma.unibo.it

(Received 12 June 2000; accepted 18 December 2000)

ABSTRACT

Epitonium (Asperiscala ?) oliverioi new species (Gastropoda, Ptenoglossa, Epitoniidae) characterizedby two different teleoconch microsculptures is described from the Tuléar region (SW Madagascar). Abrief comparison of its spawn and radular morphology with those known of other epitoniids is alsogiven in order to provide further characters for specific and supraspecific classification.

3.1–3.3 mm high. The capsules are covered with sandgrains, connected by threads probably of conchiolin,arranged in an alternate way with opposed apices, andclosely linked together at one side of the base.

Type deposition and measurements (in mm): the holo-type and four paratypes are deposited in the ZoologicalMuseum of the University of Bologna, Italy (MZB),one paratype in the Museum National d’HistoireNaturelle, Paris, France (MNHN) and another in theNatural History Museum, London, United Kingdom(BMNH).

Ribs Ribs length breadth l/b V 5mm note

Holotype MZB n° 14025 19 8.2 2.3 15 16 shellParatype 1 MZB n° 14026 17 7.7 2.2 17 18 shell

(no apex)Paratype 2 MZB n° 14027 15.8 7.3 2.2 15 15 specimenParatype 3 MNHN 10.9 5.5 2 13 14 specimenParatype 4 BMNH 9.1 4.7 1.9 13 15 ? specimenParatype 5 MZB n° 14028 8.6 4.5 1.9 13 14 ? specimenParatype 6 MZB n° 14029 5.1 2.7 1.9 14 ? specimen

(coated)

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Figure 1. Epitonium (Aspericala ?) oliverioi new species. A. Shell of the holotype (MZB n° 14025. Scale bar � 10 mm. B–G. Paratype 6 (MZBn°14029): B. Shell, scale bar � 1 mm; C. Microsculpture of the four early teleoconch whorls. Scale bar � 100 �m; D. Microsculpture of the teleoconch after the fourth whorl. Scale bar � 100 �m; E. Shell seen from the apex to count the number of lamellae. Scale bar � 1mm;. F. Protoconch with very fine slightly arcuate axial striae. Scale bar � 500 �m; G. Protoconch seen from above. Scale bar � 500 �m.

Type locality: Nosi Ve Island (SW Madagascar, Tuléarregion), 10–20 m. deep, under Fungia sp.; leg. MarcoOliverio & Raimondo Villa.

Etymology: This species is named after Marco Oliverio, malacologist of the University of Roma 1 ‘LaSapienza’, who kindly provided the material.

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Figure 2 Epitonium (Aspericala ?) oliverioi n. sp. A–D. Paratype 2 (MZB n°14026): A. Operculum, outer surface. Scale bar � 1 mm; B. SEMmagnification of external surface of operculum. Scale bar � 10 �m. C. and D. Two different views of the radula showing the diversity of teeth.Scale bar � 50 �m; E. Female with its spawn; F. Fungia sp. under which the spawn was collected; G. SEM magnification of three egg capsules.Scale bar � 1 mm; H. Thread connecting the egg capsules. Scale bar � 100 �m; I. Detail of the longitudinally striated thread connecting the eggcapsules. Scale bar � 10 �m.

DISCUSSION

Gittenberger, Goud & Gittenberger (2000) haverecently described four new species of Epitonium andgave a revised description of two other species, Epi-tonium costulatum (Kiener, 1838) and Epitonium uluPilsbry, 1921, all associated with Fungiidae (Cnidaria,Scleractinia) from Sulawesi, Indonesia. None of themis described as showing the very characteristic doublesculpture of the teleoconch of our new species, a character clearly visible under stereomicroscope at lowmagnification. E. Gittenberger (in litt.) suggests thatthe sculpture is simply fading on the lower whorls of the shell and our new species might probably be E. costulatum or (if his identification is not accepted) E. costulatum sensu Gittenberger et al. (2000) whichexhibits this kind of fading sculpture (see their fig. 22).A comparison between E. costulatum and E. oliverioibecomes necessary to give diagnostic differences. Firstly, we stress that the sculpture does not fade asseems to occur in the specimen of fig. 22 of Gitten-berger et al. (2000), it is clearly visible in the first fourwhorls of all our shells then it suddenly disappears andis no longer visible even with SEM. One of us (A. Bon-fitto) has long been studying the Red Sea epitoniidsand he never found such a character amongst thous-ands of specimens examined, nor it is described by Kilburn (1985) who wrote to us (16.05.2000) ‘thespecies looks a good one’. Our shells of E. oliverioinever reach 20 mm, shells of E. costulatum are higher:33 mm the holotype and 32 mm and 41.2 mm for otherspecimens collected by Gittenberger. Raw measuresare not diagnostic but ratios might be: length/breadthvaries from 1.9 to 2.3 in E. oliverioi while we can pre-sume from the means offered by Gittenberger et al.(2000) that in E. costulatum at the same size as our specimens it varies from 1.6 (younger shells of about 5mm length) to 1.9 (medium sized i. e. about 15–20 mm)while the value of 2.2 is reached only in the highestspecimen (probably the 32mm one). The number ofcostae is also different, if we count them on the fifthwhorl they vary from 13 to 17 in E. oliverioi and from16 to 26 in E. costulatum, while they are respectively14–18 and 16–20 if we count them where the teleoconchis 5 mm in width. Two other facts may be added: E. costulatum is one of the commonest species in the Indo-West Pacific and was always collected by Gittenbergeret al. (2000) under Ctenactis echinata (Pallas, 1766) andHerpolitha limax (Esper, 1797). Our specimens of E.oliverioi were collected under a species of Fungia whichaccording to Hoeksema (in litt.) who examined somephotographs is most probably F. (Verillofungia) rep-anda (Dana, 1846): ‘the round shape and the form of

the costal spines indicate this species being more likelythan any other’. Finally the threads connecting the eggcapsules show a different sculpture which is not an arti-fact due to twisting because the oblique lines of E. oliv-erioi are found in different threads connecting capsuleswhich lie distantly from each other. Only one other epitoniid, Epitonium (Sodaliscala) apiculum Dall, 1889,is directly comparable to E. oliverioi in showing a similar kind of spiral sculpture limited to the earlyteleoconch whorls. Nevertheless, Dall’s species has amuch smaller size (4.5 mm), the spiral sculpture is limited to the first three postnuclear whorls and theumbilicus is hidden. The two species can be easily sepa-rated also on the basis of number and morphology ofthe axial ribs which in E. apiculum show two differentdevelopment stages (Clench & Turner, 1952; Weil,Brown & Neville, 1999). In the new species the spiralsculpture is present on the first four whorls, the umbili-cus is narrowly open, the costae are peaked and showthe same kind of development on all teleoconchwhorls.

The limits of the subgenera of Epitonium are unclear;Clench & Turner (1952) applied the name Asperiscalade Boury, 1909 to all species with spiral lines betweenthe costae and placed E. apiculum in this subgenus. Kil-burn (1985), used Asperiscala in de Boury’s originalsense, restricting this subgenus to those species havingspiral lirae, a widely open umbilicus and partiallyuncoiled whorls. Weil et al. (1999) agree with Kilburn’sassessment, considering E. apiculum as Sodaliscala deBoury, 1909 on the basis of its ‘closed’ umbilicus andunpeaked costae. Considering the combination of thefeatures of the early whorls, open umbilicus, perforatesuture and peaked costae, the new species appears tobelong to Asperiscala. Neverthless, the last whorls aresmooth as in the subgenus Lamelliscala de Boury,1909. This later subgenus is characterized by a widelyfenestrate umbilicus, a deeply fenestrate (but not per-forate) suture, intervals between the costae smooth orwith faint, microscopic spiral scratches (Kilburn,1985). In the new taxon the umbilicus is narrowly open,not crossed by the axial ribs and the suture is perfor-ated, opening into the central axis.

In our opinion the new species does not fit confort-ably into any subgeneric group; neverthless we assign itto the subgenus Asperiscala only in a broad sense,rather than ‘refrain from following any subgenericclassification’ (Gittenberger et al., 2000).

Bouchet & Warén (1986) recognized 3 major types ofepitoniid radulae: a, b, c. We refer the radula of ournew species to the most common type b not because itfits the original description, but mainly because it is nottype a or c. Bouchet & Warén describe the b type as

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having bi- or tricuspid teeth ‘with the secondary cuspsituated towards the tip (as in Claviscala richardi …) ortowards the base (as in Epitonium celesti …) of thetooth’. E. oliverioi clearly has only one cusp, but in ouropinion also E. celesti has one, the second ‘cusp’ beingan angle of the tooth between its large basal part connected to the radular membrane and the projectingclaw—shaped cuspidate part. From studying the radu-lae illustrated by several authors (Clench & Turner,1952; Azuma, 1971; Warén, 1980; Kilburn, 1985,Bouchet & Warén, 1986) we are convinced that truecusps (from 1 to 3) develop only at the free end of thetooth while the angle to which we refer (secondarybasal cusp of Bouchet & Warén) might be more or lessacute and sharp thus sometimes looking like a cusp.

The spawn of the E. oliverioi n. sp. resembles thoseother epitoniid species, but appears to be species-specific. The general shape is similar to that of Epi-tonium (Clathrus) clathrum (Linnaeus, 1758) (Fretter & Graham, 1994; Bandel, 1975), of E. (Nitidiscala)georgettina (Kiener, 1839) (Pastorino & Penchaszadeh,1999) and of E. (Hyaloscala) jukesianum (Forbes, 1852)(Smith, 1998). In all these species the single egg capsules are pyramidal or polyedric, covered with sandgrains and attached directly to a single central threadanchoring the ribbon to the substrate. Nevertheless, inour new species the egg capsules are directly cementedtogether along the thread, whereas, in the other speciesthey are more or less separated each other. The same istrue for the egg capsules of E. ingridae Gittenberger &Goud, 2000, E. lochi Gittenberger & Goud, 2000 andE. costulatum (Kiener, 1838) (Gittenberger et al. 2000).Only E. ingridae and E. costulatum have the capsulesconnected base to base and with apex pointing awayfrom the string in an alternate way like in our newspecies. However, the sculpture of the connectingthreads is longitudinally striated in E. ingridae and E. oliverioi and obliquely striated in E. costulatum.

The spawn of the new species is quite different fromthose of E. (Librariscla) millecostatum (Pease, 1861)(Robertson, 1980), E. (Hyaloscala) albidum (Orbigny,1842) (Robertson, 1983), Cycloscala echinaticosta(d’Orbigny, 1842) (Robertson, 1983a as Epitoniumechinaticostatum), E. (Epitonium) ulu Pilsbry, 1921(Kay, 1979) and Epitonium sp. (Sabelli & Taviani,1984); these species have egg capsules which are ellipti-cal in outline, with several rounded mucoid projectionsat the periphery (E. millecostatum, C. echinaticosta, E.ulu, Epitonium sp.) or thick walled (E. albidum), oftenwithout sand agglutination, and occur in clusters. Thestring of E. oliverioi is also quite different from thespawn of Gyroscala lamellosa (Lamarck, 1822) whichconsists of single, round, sand-agglutinated egg cap-

sules forming a bunch of grapes in which the attach-ment of each capsules to the median string is achievedby a number of clear threads instead of one peduncle(Bandel, 1975). Our comparative observations andthose by Gittenberger et al. (2000) support the idea thategg capsules of epitoniids represent a rather good specific character and might possibly be an useful toolin understanding supraspecific relationships.

ACKNOWLEDGEMENTS:

We wish to express our gratitude to Dr. R. N. Kilburn, NatalMuseum of Pietermaritzburg, South Africa, for commentsand suggestions in preparation of this paper and for criticallyreviewing it, to Dr. E. Gittenberger for his kindness in criticalreviewing of the manuscript, to Dr. Hoeksema for the identi-fication of Fungia, to Dr. M. Taviani, Italian NationalResearch Council (C.N.R.), Bologna, who organized anddirected the Madagascar TEST REEF expedition and toMarco Oliverio, University of Roma 1 ‘La Sapienza’ for theloan of material. This research was partly financed by UETEST REEF program and partly by MURST 60% grant.

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