Bolleffino Malacologico, Roma, 38 (1-4): 4 J-44,2002 - Societa Italiana di Malacologia

The shallow-water Polyplacophora of the and some comments on the biogeographical relationships of the Azorean malacofauna

Sergio P. Avila & Andre Albergaria

KEY WORDS: Polyplacophora, Azores, biogeographical relationships.

ABSTRACT The Mollusc's reference collection of the Department of Biology of the University ofth. Azores (DBUA)was checked for Polyplacophora. A taxono­ mic list is given and new data is provided regarding the geographic distribution and bachymerric range of the Azorean Polyplacophora Some com­ ments are made about the biogeographical relationships ofGasrropocia, Bivalvia. Cephalopoda and Polyplacophora of the Azores.

RIASSUNTO E' stara analizzata la collezione malacologica di riferimento del Dipartimenro di Biologia dell'Universica delle Azzorre (DBUA), considerando i soli Poliplacofori_ Viene presentata una lisra e nuovi dari riguardanti la distribuzione geografica ed il range batimetrico dei Poliplacofori ed alcuni asper­ ti delle relazioni biogeografiche di Gasteropodi. Bivalvi, Cefalopodi e P-!iplacofori.

SERGIO P. AVILAI & ANDRE ALBERGARIA2 SeCl;ao de Biologia Marinha, Departamento de Biologia, Universidade dos Ac;ores 9500 Ponta Del­ gada, Ac;ores, . I, email: [email protected]; 2, email: [email protected]

INTRODUCTION RESULTS Among the few works that have been published abour rhe A total of 80 I samples of the DBUA collection were studied, shallow-water Polyplacophora of the Azores during the last cen­ of which 53 yielded Polyplacophora. tury, the majoriry dealt with the systematics and distriburion of Of the six species of Polyplacophora reported from (ile Azo­ this group (DAUTZENBERG, 1889; 1927; KAAs & VAN BELLE, res, Acanthochitona discrepans is considered to be a dubious record 1981; 1985a; 1985b; MAC ANDREW, 1856; MACEDO et al_, and three species were confirmed by us: Hanleya hanleyi. Lepido­ 1999; NOBRE, 1924; VAN BELLE, 1984). Only in the last decade chitona simrothi and Acanthochitona jascicularis. The mosr com­ the ecology of this class has been studied (AZEVEDO, 1991; BUL­ mon Polyplacophora in the Azores are A. ja.rciculariJ:md the LOCK, 1995; HAWKINS et aI., 1990; MORTON et aI., 1998). endemic species L. simrMhi, appearing in 52 out of the 53 repor­ It is our intention to provide new data about the geographic ted samples. The Azorean Polyplacophora have higher similari­ distribution and bathymetric range within the Azores of the ties with the Canary Islands, Boreal Province (Scandinavia and species of this class and to establish the biogeographical rela­ British isles) and the Lusitanian Province (mainland of Portu­ tionships of the marine- malacofauna of the Azores. gal) than wirh (he or the eastern coasr of north America (see Table 1). MATERIALS AND METHODS Polyplacophora from the Mollusc's reference collection of (he TAXONOMIC LIST Department of Biology of the University of the Azores (DBUA) Phylum MOLLUSCA were studied. The Polyplacophorain this collection were sampled Class POL YPLACOPHORA between 1989 and 1999 by diving at depths up to 45 m. Dives Order LEPIDOPLEURIDA were made by the Marine Biology ream of che Universiry of the Family Hanleyidae Azores at Pica, Faial, Flores, Sao Miguel and Formigas islets. Hanleya hanleyi (Bean in Thorpe, 1844) A literature review was made and information included in Hanleya hanleyi (Bean In Thorpe, 1544) Azores (KAAS & V AN the taxonomic list presented. BEUE, 1985a: 193-196). Species were identified using KAAS & V AN BELLE 0985a; Marerial examined: DBUA 551 (Porro da Baleia, Flores)

1985b; 1987; 1990; 1994) and the classification follows the Bathymetry from 15 down (0 55 5m depch (KAAS & V AN CLEMAM database, All specimens were measured to the nearest BELLE, 1985a). mm, Dorsal elevation is the ratio height of regmencum/widch Dimensions: length = 7 mm; breadth = 4 mm, dorsal elevation (see KAAS & V AN BELLE, 1985a). = 0,3.

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Table 1: Geographic distribution of the Azorean Polyplacophora. AZO - Azores; MAD - Madeira archipelago; CAN - Canary Islands; BRI - British isles; POR - mainland of Portugal; MED - western Mediterranean; SCA - Scandinavia; AME - eastern coast of north America. 1- presence, 0 - absence.

AZO MAD CAN BRI POR MED SCA AME Hanleya hanleyi 1 1 1 1 1 1 1 1 Callochiton JeptemvalviJ 1 0 1 1 1 1 1 0 Lepidochitona piceola 1 0 1 0 0 0 0 0 Lepidochitona J imrothi 1 0 0 0 0 0 0 0 Acanthochitona jasciCl//al'iJ 1 1 1 1 1 1 0 0 % Shared species 100.0 dO.O 80.0 60.0 60.0 ()(). () 40.0 20.0

Geographic distribution: from the Barents Sea down to Geographic distribution: endemic to the Azores (Pico, Faial, Algarve (Portugal), the Mediterranean, rhe Azores (Flores), Flores, Sao Miguel and Formigas islets). Madeira, Canary Islands, near ireland, (;reenland and rhe Remarks: specimens recorded by HAWKINS 1'1 (/1. (1990: 27- eastern coast of north America (KAAS & V AN BELLE, 1985a). 28) and AZEVEDO 0991: 29) probably belong to this species but were not identified at species level. These specimens were Family Ischnochitonidae not present in the DBUA collection and could not be examined Callochiton septemva/t,is (Montagu, 1803) by us. Callochiton achatimlJ (Brown, 1827). Urzelina bay, under stones (MORTON, 1967: 36). Family Acanthochitonidae Bathymetry: from subtidal to 500 m depth (KAAS & VAN Acanthochitona discrepans (Brown, 1827) BELLE, 1985b). Anisochiton discrepans Brown, 1827. Azores (MAC ANDREW, Dimensions: length = up to 22 mm; dorsal elevation = 0.35 to 1856: 145). Sao Miguel (DAUTZENBERG, 1889: 72). 0.46 (KAAS & VAN BELLE, 1985b). Chiton discrepans (Brown, 1827). Sao Miguel () Geographic distribution: all Aclancic coasts of Europe, from (NOBRE, 1924: 84; 1930: 61). Scandinavia and British isles, south to the Canary Islands. Also Bathymetry: from the intertidal zone down to 40 m depth. It in the Mediterranean Sea (KAAS & V AN BELLE, 1985 b). lives mainly on stones covered with algae in muddy zones (MACEDO el ai., 1999). Lepidochitona piceoia (Shuttleworth, 1853) Dimensions: length = 25-30 mm (MACEDO et ai., 1999). Lepidochitona pireo/a (Shuttleworth, 1853). Sao Miguel (intertidal Geographic distribution: British isles, French Atlantic coast zone) (KAAS & V AN BELLE, 1981: 23; 1985b: 89-91). (KAAS, 1985) and the Azores (?). Dimensions: length = 10 mm; breadth = 6 mm; dorsal eleva­ Remarks: this is a dubious record. The specimens from Mac tion = 0.31 (KAAS & VAN BELLE, 1985 b). Andrew, Dautzenberg and Nobre are to be examined (STRACK, Geographic distribution: Canary Islands and the Azores (KAAS in litt.). So far, the occurrence of this species in the Azores & VAN BELLE, 1985b). remains highly questionable.

Lepidochitona simrothi (Thiele, 1902) Acanthocbitona /ascimlaris (Linnaeus, 1767) Lepidochilona simrothi (Thiele, 1902). Azores (V AN BELLE, 1984: AnisoriJiton jascimlaris Linnaeus, 1766. Azores (MAC ANDREW, 224-226). Flores, Faial, Terceira, Santa Maria and Sao Miguel 1856: 145). (KAAs & V AN BELLE, 1981: 27-29; 1985b: 93-95). Sao Miguel Acanthochites adansoni de Rochebrune, 1881. Faial (Horta, -20m) (BULLOCK, 1995: 16). Azores (MORTON etal., 1998: 57). and Flores (Santa Cruz, -40m) (DAUTZENBERG, 1927: 232). Lepidochilona sp. Azores (MACEDO et ai., 1998: 75). Acanthochitona communis (Risso, 1826). Azores (V AN BELLE, Material examined: DBUA 190, 191, 193,524,554 and 562- 1984: 227). Flores (all intertidal zone); DBUA 337 - Formigas islets (interti­ Acanthochitol1a jascimlaris (Linnaeus, 1767). Sao Jorge (Urzelina dal zone); DBUA 457, 458, 459, 465, 475, 662 - Pico (0 to 3 m bay) (MORTON, 1967: 36). depth); DBUA 625,715,732,740,741,743,744,745,746, Material examined: DBUA 176,637,683,700,719,721,730, 747,785,793 -Sao Miguel (intertidal zone down ro 14 m depth). 731,732,733,748,751,752,767,794 - Sao Miguel (interti­ Bathymetry: littoral and sublittoral (up to 14 m depth). dal zone down to 20 m depth);DBUA 240, 569,574,577,799 Dimensions: length = 5-8 mm; breadth = 3-4 mm; dorsal ele­ - Flores (intertidal zone down to 20 m depth); DBUA 410, vation = 0.37. 433,801 - Faial (10 m down to 23 m depth); DBUA 486,667,

> 42 < Tile shallow-water Polyplacophora d' the Azores and some comments on the biogeographical relationships of the Azorean malacofauna

671,726,800 - Pico (intertidal zone down to 15 m depth). REFERENCES Bathymetry: from the intertidal zone down to 50 m depth (V AN AVII.A, S. P., 2000. Shallow·wa,er marine molluscs of [he Azores: biogeographi­ cal relationships. Ar(l"i/"I"p' Life and marine Sciences. Supplement 2 BELLE, 1984). (Pan A), Hona: yy.1.) I. Dimensions: length = 26 mm; breadth = 16 mm. A/'I: \' F.J)( >, J. iv1. N .. l)l') I. f..1/Ift!rl tld.1 (/llIIllfJid"t/I:,f J/I{r/a(o/(;git"aJ /ilaiJ du liloral em Colour: extremely variable (black, olive, orange, whi [ish). .\,//1 I\l/.~/(('/. /\(lll"n. Pro\";ts de A.P.C.C .. UniversiJaJe Jos A\ores, Ponta Geographic distribution: Bri([any (France) and sourhern 1)L'I~ada, IV. 7 SlOp. England co Madeira, Canary Islands, in the whole Mediterra­ BLJI.I.OCK, R. C, J YY5. Tht distribution of ,he molluscan fauna associated with nean Sea (KAAS, 1985) and the Azores (Pico, Faial, Sao Jorge, [he intenidal coralline algal turf of a partially submerged volcanic cra­ Flores and Sao Miguel). ter, rlie 1I1ltl! de Vila Franca, Sao Miguel, Azores. In Martins, A. M. de F.

Hermann Strack were crucial I n relevant parts of [his paper. We KAAS, 1'. &: R. A VAN BeLLE, IYHI The genus Lepido(hilOIlIl Gray, 1821 (Mollu­ sea: l'IJI)'l'lamphora) in [he nonheas[ern Atlantic Ocean, rhe Medi[er­ also thank Peter Winz, for donating specImens of A jClJ(f(!l/,mJ. rant'an Sea and the Black Sea. ZoulogiJdJe VerhandelinRell 185: 1-43, This study was supported by grant JNICT (PRAXIS fjgs. 1-128. XXI/BICl27RR/96) and by PRAXIS/212 I fBI All ()919i Tht: fir­ K,\t\s, I', &:.. I{ A V (\,~ BEI.I.E, Il)H),L i\!fJ}/(I,t.;l'tlj)j; r11ill1111{ (hi/ow ({\lul/lIJ(a: Puly­ st author was supporteJ by graIl( PRAXiS XXlIBIU27SS/96 i,I",·"pb",.,i!. V,,1. I. E. 1. Urill Publishers, Leiden, I: 240 pp.

Table 2: Number and percentage of shared species between the malacofauna of a given region and the Azores (236 confirmed taxa). ASC - Ascension Island; S TH - Saint Helen Island; remaining abbreviations as in Table 1.

AZO r,!{, shared species SCA 80 33.9 BRI 115 48.7 POR 147 62.3 MED 184 78.0 MAD 149 63.1 CAN 141 59.7 ASC 13 5.5 STH 12 5.1

AME 2'.J 9.7

> 43 < Sergio P, Avila & Andre Albergaria

KAAS, P. & R. A VAN BELLE, 1985b. ,\Ionograp!' of li,'in.~ ,!,ilom (!\lolllIJro: Polypl,,­ copbora). Vol. 2. E. J. Brill Publishers, LeiJen, 2: 19R pp.

KhhS, P. & R. A V AN BELLE, 1987. Monogri1ph of Ii"illg ,bilOllJ (Mollmld: Polypla­ copbora). Vol. 3. E. J. Brill Publishers. Leitien, 3: .'I()2 pp.

KAAS, P. & R. A VAN BELLE, 1990. {\Iollogra/,h,if li"illg ,hiloll! (,\lollm,d: Poly/,I,,­ copbora). Vol. 4. E. J. Brill Publishers, Leiden, 4: 298 pp.

KAAS, P. & R. A VAN BELLE, 1994. ;\Ionograph of li,·ill.~ ,b'l'o,,,, (,\f"IIII""": Polypl,,­ copbor,,). Vol. 5. E. J. Brill Publishers, L";den, 5: ·W2 PI'.

MAC ANDREW. R., 1856. Report on the marine testaceous Mollusca of the North-Easr Atlantic and neighonuring Seas anti the ph),,;cal conditions affecting their development. i?epol'l ,if Ibe Brir. A.uo,. fo(, the Ad". 0/5,." London, 158 pp.

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MORTON, B., 1967. Malacological Report. Cbel'e" College Azore,\ Expedition. Jllly - October 1965. Fi",,1 Report: 30-38

MORTON, B.,J. C. BRITTON & A. M. F. M,\RT!NS, 1t)9H. F.(I'/I)gftl CI){/eira dOJ Afo­ reJ. Sociedade A fonso Chaves, Ponra Del!(ada, X + 2,. ') pro

NOBRE, A. 1924. Contriblli~6es para a fauna dos A~ores. An. Imt. Zoo/. Unil'. Porto, 1: 41-90.

NOHIH., A., l~.nO. 1\ltf/t'r;dll /1,/1"11 /I (Iuliln d" I;'"IJ.I £1111 /\(flI"n Ill\lictHlJ lit- 1'.(H11Il)!I;1 d,l Univc.:rsili;llk dn Pnrw, PonD, IOHpp.

VAN BELLE. R. A., 1984. De Polyrlacorhora van de Azortn. Gil/ri'l Mari.r, 23(10): 223-230.

Lavoro accettato il 9 Settembre 2001 ._-.------

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