Based on an examination of several collections made in Maltese waters, 20 cephalopods are recorded of which three genera and seven species are reported for the first time from Maltese waters. The identity of some previously dubious records is clarified. Information is given on the material examined during the present study as well as on geographical distribution and habitat preferences of the species. Notes on the diagnostic charactcrs required for accurate identification and details of important diagnostic features arc included. All the species recorded are also known from the Strait of Sicily and other areas in the Central Mediterranean. There are very few Maltese records of pelagic species. This is partly a result of the fishing techniques used by local fishermen and partly because cephalopods are only a by-catch in Malta.peer-reviewe

Schembri, Patrick J.

Schembri, Titian

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The Central Mediterranean Naturalist - Vo!. 2 (4) 1997. RECORDS OF CEPHALOPODS (MOLLUSCA: CEPHALOPODA) FROM MALTESE AND SURROUNDING WATERS (CENTRAL MEDITERRANEAN) Titian Schembril and PatrickJ. Schcmbri l ABSTRACT Based on an examination of several collections made in Maltese waters, 20 cephalopods are recorded of which three genera and seven species are reported for the first time from Maltese waters. The identity of some previously dubious records is clarified. Information is given on the material examined during the present study as well as on geographical distribution and habitat preferences of the species. Notes on the diagnostic charactcrs required for accurate identification and details of important diagnostic features arc included. All the species recorded are also known from the Strait of Sicily and other areas in the Central Mediterranean. There are very fcw Maltcse rccords of pelagic species. This is partly a result of the fishing techniqucs used by local fishermen and partly because cephalopods are only a by-catch in Malta. INTRODUCTION Although many species of cephalopod molluscs are sold commercially and they are invariably present in fish markets, little valid scientific information has been published about the Maltese specics. In his Repertorio di Storia Naturale, Gavino Gulia (1858-1859) mentions two species of cephalopods but offers no information other than the local names. A. A. Caruana, editor of the Enllluerato Ordinata Molluscorurn Gau/o-MelifeIlSilllrT of the deceased G. Mamo, lists nine cephalopods (Mamo in Caruana, 18(7). A review of the fauna of the Maltese Islands by Giovanni Gulia (\ 914) mcntions three ncw records of cephalopods for the Maltese Islands. This work is very intcresting in that it includes Tremoctopus violaceus, a pelagic species similar in ecology to Argoll([lIta argo and Ocythoe tuberct/lata, which is rarely encountered. It has ncvcr been recorded since and the possibility that it could have bcen lIlisidcntificd is not excluded. Micallef & Evans (1968) record six cephalopods. Some of their records are dubious as the reference work used by these authors to identify their specimens is not a reliable one for identification of cephalopods. Cachia (1l)73) deals with shelled molluscs collected from local shores and only records Argollow{[ {[rgo, referring to the calcified egg-case of this species that is often washed ashorc. I Department uf Biology, Uni versity or Malta, Msida, Malta. 124 The most recent work is that of Cachia et al. (1993) who published a list of molluscs present in the Maltese Islands, including 12 species of cephalopods. That Spirula spirula is included in this list is interesting. This is a mesopelagic species that inhabits the Atlantic, but which has not yet been recorded live from the Central Mediterranean. The only Central Mediterranean records are of shells that often float for some distance after the organism is dead (Guerra, 1993). Most of the above publications lack essential taxonomic information about the species mentioned; none include illustrations of diagnostic features or guidelines for identification. Some of the records are actually suspect as the identification was based on literature that is not detailed enough for accurate taxonomic study. It is thus clear that a revised, detailed account of the cephalopod fauna of Maltese waters is now due. Apart from providing such an account, the present work serves to highlight gaps in the knowledge of the Maltese cephalopod fauna and it is hoped that it will serve as a basis for future studies leading to a deeper understanding of the cephalopods of the Maltese Islands. MATERIALS The majority of specimens of the smaller and rarer species were obtained from the private collections of amateur and professional researchers. Most of the remaining specimens examined were obtained during visits to the fish markets at Marsaxlokk and at Valletta. Some divers and local amateur fishermen supplied live specimens, egg cases or clusters, and parts from specimens that could not be collected whole. The male hectocotylised arm and the beak were obtained when the whole specimen was not available. Beach combing produced an assorted array of different cuttlebones belonging to the genus Sepia. The collections on which the older published records are based could not be traced and probably no longer exist. The 'previous records' cited here are therefore taken entirely from these publications, none of which contain illustrations. In total, 114 specimens were examined together with numerous cuttlebones, beaks and eggs. The specimens obtained from the collection of Mr C. Mifsud are coded CM in the species list below. The rest were collected by the authors and are coded TS and PJS. Identifications were made using the published keys and guides by Guerra (1992) and Bello (1995). Beaks were identified using Clarke's (1986) keys. Some 125 specimens of Sepiolidae were dissected to examine the light organs as described by Bello (1995). Specimens are housed in the reference collections of the Department of Biology of the University of Malta and in the private collection of Mr C. Mifsud, Rabat, Malta. SPECIES LIST In the following list, each species is followed by previous records from the Maltese Islands, a catalogue of the material examined during the present study, and taxonomic and ecological notes where appropriate, in that order. All localities are situated in the island of Malta unless otherwise stated. Sex of the specimens examined, when known, is indicated by M for males and F for females. The list presented follows the systematic arrangement given by Guerra (1992). SEPIIDAE Keferstein, 1866. Sepia officinalis Linnacus, 1758 [Figures I G, IP] Sepia officina lis, L.; Mama in Caruana, 1867 Sepia officinalis, L.; Micallef & Evans, 1968 Sepia officinalis Linnaeus, 1758; Cachia et al., 1993 IM,2F: Marsaxlokk Fish Market, summer 1995 (TS); several cuttlebones (PJS, CM); IF: Dahlet il-Fekruna, July 1974 (PJS). Sepia elegans Blainville, 1827 [Figures I E, I MJ Sepia elegans Blainville, 1827; Cachia et al., 1993 30 (juv.): Valletta Fish Market, summer 1995 (TS); several cuttlebones (PJS, CM); 4 (juv.): trawled by fishermen at I00I200m, November J 993 (CM). Sepia orbigllyana Ferussac, 1826 [Figures I A, lP, J N J New record. IM: 2 miles off Gnejna (Gozo), 200m (CM); 1 (cuttlebone): 60 miles off SE Lampedusa, lOOm, August 1977 (PJS); I (cuttlebone): Valletta Fishmarket, February 1988 (PJS); several cuttlebones: Malta, no other data (CM). 126 SEPJOLIDAE Leach, 1817. Single individuals of species belonging to the genus Sepiola were not dissected to examine the internal structures described by Bello (1995) in his key. This was done to avoid destroying the only available specimens of these species. However, all the specimens were males and their identification, based on the hectocotylised arm, is considerf'd conclusive. Rossia macrostoma (Delle Chiaje, 1830) [Figures IB,IO] New record. IF: 60 miles off SE Lampedusa, lOOm, August 1977 (PJS). Sepiola ligulata Naef, 1912 [Figures I C, I H] New record. 2M: Mdina Bank, 70m, July 1977 (CM). Sepiola robusta Naef, 1912 [Figure 11] New record. IM: Mdina Bank, 70m, July 1977 (CM). Sepiola rolldeleti Leach, 1817 [Figures ID, IJ] Sepiala rondeleti, Leach.; Mamo in Caruana, 1867 Sepiala rondeleti Gesner; Micallef & Evans, 1968 Sepia la rondeletii Leach, 1817; Cachia et al., 1993 3 Guv.): Ta' Kanini, January 1976 (CM); 2M: Mdina Bank, 70m, July 1977 (CM); 6?: 60 miles off SE Lampcdusa, lOOm, August 1977 (PJS); 1 Guv.): Blata Steps, 170m, May 1990 (CM); 1 (juv.): Qammieh, 60m, October 1990 (CM); 2?: trawled by fishermen, I00I200m, November 1993 (CM); Eggs: Pasidonia meadow, off White Tower, 21m, January 1994 (TS); Eggs: Anchor Bay, April 1995 (CM). 127 .~~. ~\ ~~~ (~ \ 1 I \ ) A\v.J ~;!;, [K} \ . ~. Fig. 1: (Scale bar length in brackets) A, Sepia orbignyana (20111111); B, Rossia macrostoma (20I11m); C, Sepio/a ligulata: mantle (20mm); D, S. rolldeleti: mantle (20mm); E, Sepia elegans: cuttlebone (20mm); F, S. orbignyana: cuttlebone (20mm); G, S. officinalis: cuttlebone (20mm); H, Sepiola ligulata: ligula (8mm); I, S. robusta: ligula (8mm); J, S. rondeleti: ligula (8mm); K, S. afalallfica: ligula (8mm); L, S. intermedia: ligula (8mm); M, Sepia elegalls: tentacle club (I Omm); N. S. orbignyana: tentacle club (IOmm); 0, Rossia IIIGcros(Of/lO : tentacle club (lOmm); p, Sepia officinCllis: tentacle club (I Omm). (All drawn from life) 1'10 Sepiola intermedia N aef, 1912 [Figure IL] New record. IM: Mdina Bank, 70m, July 1977 (CM). Sepiola atalantica Orbigny, 1840 [Figure IK] New record. lM: Mdina Bank, 70m, July 1977 (CM). LOLIGINIDAE Orbigny, 1848. Loligo vulgaris Lamarck, 1798 [Figures 2B,2D] Loligo VUlgaris, Lamk.; Mamo in Caruana, 1867 Loligo vulgaris Lam.; MicalIef & Evans, 1968 Loligo vulgaris Lamarck, 1798; Cachia et al., 1993 1 Guv.): 2 miles off Gozo, November 1976 (CM); 4 Guv.): trawled by fishermen, 1001200m, November 1993 (CM); 3F: Marsaxlokk Fishmarket, summer 1995 (TS); 2F: ValIetta Fishmarket, summer 1995 (TS). OMMASTREPHIDAE Steenstrup, 1857. Illex coindetii (Verany, 1839) [Figures 2F,2G] Loligo sagittata Lamk.; Mamo in Caruana, 1867 Loligo sagittatus; Gulia, J 912 lllex coindetii (Verany, 1839); Cachia et aI., 1993 2M, I F: Valletta Fishmarket, summer 1995 (TS); 2M: Marsaxlokk Fishmarket, summer 1995 (TS). Todaropsis eblanae (Bell, 1841) [Figures 2E,2G] New record. 1 M: 60 miles off SE Lampedusa, lOOm, August 1977 (PJS). 129 Todarodes sagittatus (Lamarck, 1798) [Figures 2A,2C] Loligo todarus Delle Chiaje; Mamo in Caruana, 1867. Todarodes sagittatus (Lamarck, 1798); Cachia et al.. 1993 3M: Malta (no other data), November 1993 (CM). OCTOPODIDAE Orbigny, 1840 Octopus vulgaris Cuvier, 1797 [Figures 21,20] Octopus tuberculatus Blain.; Gulia, 1859 Octopus vulgaris, Lamk.; Mamo in Caruana, 1867 Octopus vuLgaris Lam.; MicaIlef & Evans, 1968 Octopus vuLgaris Cuvier, 1798; Cachia et al., 1993 I F: Malta (no other data) (PJS); 1 F: Gnejna Bay, 3m, August 1988 (CM); 4F: Marsaxlokk Fishmarket, summer 1995 (TS); 2 (hectocotylus): VaIletta Fishmarket, summer 1995 (TS); 10 (hectocotylus, beak): (no other data), summer 1995 (TS). Octopus macro pus Risso, 1826 [Figures 2J,2P] Octopus ruber Ratinesque.; Mamo in Caruana, 1867 Octopus mllcropu.\' Risso, 1826; Cachia et al., 1993 2 (heclocotylus): ValJetta Fishmarket. summer 1995 (TS). Scaeurgus unicirrhus (Delle Chiaje, 1840) [Figure 2H] New record. I M: Malta (No other data); ?1 F: Mdina Bank, 70m, July 1977 (CM). One adult male specimen wrongly identified as Octopus vulgaris was housed in the collection of the Department of Biology of the University of Malta. While it is certain that this specimen was captured in Maltese waters, no other data is available. The other specimen examined was in a bad state of preservation and could not be identified with certainty. 110 ; E ~F Fig. 2: (scale bar length in brackets) A. Todarodes sagittatus (I30mm); B. Loligo vulgaris (130mm); C. T. sagittatus: tentacle club (lOmm); D. Loligo vulgaris: tentacle club (I0mm); E. Todaropsis eblanae: tentacle club (lOmm); F. Illex coindetii: tentacle club (lOmm); G. T. eblanae (left) and I. coindetii (right): hectocotylus (IOmm); H, Scaeurgus unicirrhus: ligula (lOmm); I. Octopus vulgaris: ligula (lOmm); J. Octopus macropus: ligula (lOmm); K. Eledone moschata: hectocotylus and tentacle (lOmm); L. Eledone cirrhosa. hectocotylus and tentacle (lOmm); M. Argonauta argo: hectocotylus (lOmm); N. Ocythoe tuberculata: hectocotylus (IOmm); O. Octopus vulgaris: arm length (lOmm); p. O. macropus: arm length (lOmm); Q. E. cirrhosa: mantle shape (lOmm); R. E. moschata: mantle shape (10mm). (All drawn from life except M and N which are after Guerra. 1992) 131 Eledone cirrhosa (Lamarck, 1798) [Figures 2L,2Q] New record. 1: 60 miles off SE Lampedusa, lOOm, August, 1977 (PJS); 6: trawled by fishermen, March 1995 (CM). Eledone moschata (Lamarck, 1798) [Figures 2K,2R] Eledone moschata, Lamk.; Mamo in Caruana, 1867 Eledone moschata (Lamarck, 1798); Cachia et aI., 1993 I: Anchor Bay, 60m, July 1993 (CM). OCYTHOIDAE Gray, 1849 Ocythoe tuberculata Rafinesque, 1814 [Figure 2N] Philonexis atlanticus; Gulia, 1913 Ocythoii tuberculata Rafinesque; Micallef & Evans, 1968 Ocythoe tuberculata Rafinesque, 1814; Cachia et aI., 1993 2F: Malta (no other data) (PJS); l(juv.): 60 miles off SE Lampedusa, lOOm, August 1977 (PJS). Both adult specimens originally housed in the collection of the Department of Biology of the University of Malta are now lost. ARGONAUTIDAE Caintraine, 1841 Argonauta argo Linnaeus, 1758 Argonauta argo, L.; Mamo in Caruana, 1867 Argonauta argo L.; Micallef & Evans, 1968 Argonauta argo (Linn.); Cachia, 1973 [Figure 2M] Argonauta argo Linnaeus, 1758; Cachia et aI., 1993 1: Malta (no other data) (PJS). DISCUSSION This report confirms the presence of 11 species of cephalopods previously recorded from the Maltese Islands and their surrounding waters (Gulia, 1859; Mamo in Caruana, 1867; Gulia, 1913; Micallef & Evans, 1968; Cachia, 1973; Cachia et al., 1993). Another nine species are recorded here for the first time, increasing the total number of cephalopods known from the Maltese area to 20. We do not consider it appropriate to include Spirula spirula (Cachia et al., 1993) in the Maltese list until a whole specimen has been collected from Maltese waters, as the empty internal shell of this species is known to remain afloat and to travel for long distances. Spirula spirula is a mesopelagic Atlantic species that only occasionally enters the Mediterranean; whole specimens are sometimes encountered in Moroccan waters, however, the empty shell may be carried by currents as far as the Levantine Sea (Bello, 1990; 1992). Of the 60 species of cephalopods recorded from the Mediterranean (Bello, 1986; 1992), about 59 are known from the Western Mediterranean, 38 from the Adriatic, and 47 from the Eastern Mediterranean (Mangold & Boletzky, 1988). The Maltese cephalopod fauna includes about 33% of the total cephalopod species present in the Mediterranean. This is quite a low figure when one considers that the islands are situated close to the boundary between the two main basins of the Mediterranean. In the Central Mediterranean, 38 species have been recorded in a census of the cephalopod fauna of the Strait of Sicily (Jereb & Ragonese, 1994); only 12 of these are known from the Maltese Islands. Corresponding figures for the Gulf of Taranto are 28 species recorded (Bello, 1986) of which 16 occur also in' Malta, and for the Gulf of Castellamare, 27 species recorded (Bello et al., 1994), of which 12 occur in Malta. Therefore, the Maltese cephalopod fauna includes roughly 45% of the fauna of the Central Mediterranean. It is thus evident that many of the species known from the Strait of Sicily could also be present in Maltese waters but have not yet been discovered or documented. One reason for this could be the way cephalopods are exploited locally. Cephalopods are captured as by-catches of the commercially important fish species caught by pe\agic and bottom trawling and by purse seines. The by-catch is often sold or used by the fishermen themselves without being exhibited at the local fishmarkets, hence it is difficult to monitor these catches. Secondly, comparison of the species list from Maltese waters with that from the surrounding area shows that the local list lacks those species which frequent waters deeper than lOOm. One exception is Todarodes sagittatus which inhabits depths ranging from 350 to 540 m. However, all the recorded species are known to migrate to shallower waters to reproduce and the greatest catch biomass of cephalopods sold at the Valletta fishmarket each year corresponds to the reproductive seasons for 133 the various species. Octopuses are generally caught mainly from March to June and, lately, from November to December. Cuttlefish are caught from November to April, and squid from June to August and from November to January. Species not rising to surface waters to spawn are not represented. It is also possible that some species no longer occur in shallow areas perhaps due to over-exploitation. Catche statistics in fact show a decreasing catch-biomass, but this could be due to other reasons, such as the reduction in fishing effort. The species list provided here is therefore by no means exhaustive. The present work should be considered as a starting point and it will hopefully be improved upon by further research. ACKNOWLEDGEMENTS We would like to thank the following persons for help received during the preparation of this report: Constantine Mifsud for putting his collection of Maltese cephalopods at our disposal and for allowing us to report his records; Edwin Lanfranco for help in establishing contacts and for his friendship and interest, and Joseph A. Borg, Antonio Anastasi and their fellow divers for collecting specimens. This work was supported by a research grant from the University of Malta, for which we are grateful. REFERENCES Bello, G. (1986). Catalogo dei mol1usci cephalopodi viventi nel Mediterraneo. Boltettino Malacologico 22 (9-12): 197-214. Bello, G. (1986). I cephalopodi del Golfo di Taranto. Lavori delta Societa ltaliana di Malacologia 22: 77-84. Bello, G. (1990). Guida all'identificazione delle conchiglie dei cephalopodi del Mediterraneo. Bollettino Malacologico 26(10-12): 157-164. Bello, G. (1992). Addenda al catalogo dei molluschi cephalopodi viventi nel Mediterraneo. Bollettino Malacologico 28(\-4): 93-95. Bello, G., Pepitone, C. and Arculeo, M. (1994). I cephalopodi dei fondi strasciabili del Golfo di Castellamare. Bollettino Malacologico 30(5-9): 173-181. Bello, G. (1995). A key for the identitication of the Mediterranean sepiolids (Mollusca: Cephalopoda). Bulletin de /'lnstitut Ocianographique, Monaco, nO special 16: 41-45. Cachia, C. (1973). Further notes on marine shelled Mollusca. The Maltese Naturalist, Malta 1(4): 30-32. Cachia, c., Mifsud, C. and Sammut, P. M. (1993). An annotated checklist of the Inarine Mollusca of the Maltese Islallds. Rankweil, Austria: Erste Vorarlberger Malakologische Gesellschaft; 80pp. Clarke, R. (1986). A handbook for the idellfificafion of cephalopod beaks. Oxford: Clarendon Press; 273 pp 1 ~A Guerra, A. (1992). Mollusca, Cephalopoda. [Fauna lberica Vol. I] Madrid: Museo Nacional De Ciencias Naturales: 327pp. GuJia, Gavino. (1858-1859). Reperto di storia naturale. Malta: Anglo-Maltese, iii + 246 pp. GuJia, Giovanni (1914). Uno sguardo alia zoologia delle "Isole Maltcsi". IX',"e Congres International de Zoologie (Monaco, 1913). Sect. 4: 545-55; Rennes, France. Jereb, P. and Ragonese, S. (1994). The Mediterranean teuthofauna: towards a biogeographical coverage by regional census. II: Strait of Sicily. Bollettino Malacologico 30(5-9): 161-172. Mamo, G. (in Caruana, A. A. 1867). Enumeratio ordinata Molluscorum Gaulo-Melitensium of the late Mr. Giuseppe Mamo. Malta: British Press. 78 pp. Mangold, K. and Boietzky, S. (1988). Mediterranean cephalopod fauna. In: Clarke M. Rand Trueman E. R. (eds.), The Mollusca, Vo!. 12: Paleontology and neontology of cephalopods; pp. 315-330; London: Academic Press. Micallef, H. and Evans, F. (1968). The marine fauna of Malta. Malta: The Royal Uni versity of Mal ta; vi + 16 pp. (Received 14th March 1997; accepter! 2(i' April 1997) 135 

Records of Cephalopods (Mollusca : Cephalopoda) from Maltese and surrounding waters (Central Mediterranean)

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Records of Cephalopods (Mollusca : Cephalopoda) from Maltese and surrounding waters (Central Mediterranean)

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