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vulgaris is currently rare in Irish waters. Keywords: Octopus vulgaris, Eledone cirrhosa, Irish records .... the Irish Sea, specifically from Liverpool Bay and.
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This article should be cited as: Quigley, D.T.G. and Flannery, K. (2014) The Common Octopus (Octopus vulgaris Cuvier) in Irish waters. Irish Naturalists’ Journal 33(2): 124-127.

Date of publication: 16 June 2014

Common Octopus in Irish waters

The Common Octopus (Octopus vulgaris Cuvier) in Irish waters

Figure 1. Large specimen of the Common Octopus (Octopus vulgaris) caught in Dingle Bay, Co. Kerry.

*Declan T.G. Quigley and Kevin Flannery

Dingle Oceanworld (Mara Beo Teo), The Wood, Dingle, Co. Kerry The third authenticated record of the Common Octopus (Octopus vulgaris Cuvier) is reported from Irish waters and the species status is reviewed in terms of both historical and recent information. It was concluded that O. vulgaris has been, and continues to be, frequently confused with the more commonly occurring Lesser Octopus ((Eledone cirrhosa (Lamarck)) and that O. vulgaris is currently rare in Irish waters. Keywords: Octopus vulgaris, Eledone cirrhosa, Irish records On 28 March 2005, the MFV Elsie Maria II (T114) [Skipper: David Granville, Dingle], captured a large specimen of the Common Octopus (Octopus vulgaris Cuvier, 1797) while trawling in Dingle Bay (c.520 04’N, 100 20’W), Co. Kerry, SW Ireland (Fig. 1). The following morphometric details were recorded: total length, 103 cm; mantle length 21cm; maximum length from tip of beak to tip of arms 89 cm; maximum arm span 160cm; weight 3.75kg. There were two longitudinal rows of suckers on each arm. The current specimen, which is the third authenticated record of O. vulgaris from Irish waters, was donated to the National Museum of Ireland (NMINH:2007.25.1). Octopus vulgaris is generally considered cosmopolitan, nominally with global distribution in temperate and tropical waters (Roper et al. 1984). It is a species complex awaiting full description within which the historically designated species has a distribution centred on the Mediterranean (Mangold and Hochberg 1991, Mangold 1998). However, recent genetic evidence has shown that the species is also present on both sides of the Atlantic and Indian Oceans including South Africa, Amsterdam and Saint Paul Islands, Taiwan and Japan (see Guerra et al. 2010 and references therein). Historically, the occurrence of O. vulgaris in Irish waters has been described as “not uncommon”. However, Thompson (1856) and Nichols (1900) were of the opinion that these probably referred to the Lesser Octopus (Eledone cirrhosa (Lamarck, 1798)) which is known to be common all around the Irish coast (Gibson et al. 2001, Dr Julia Nunn pers. comm.) and in offshore waters down to depths of 490 m (Collins et al. 2001). Elsewhere in the north*Corresponding author – [email protected] 124  Irish Naturalists’ Journal Vol. 33 Part 2

east Atlantic, E. cirrhosa ranges from Iceland (to 670N) southwards to the Mediterranean (Roper et al. 1984). Haddon (1886) expressed doubts about the authenticity of specimens of O. vulgaris reported from Bray, Co Wicklow (Macalister and McNab 1878) and North Strand, Dublin Bay (Mackintosh 1884). However, he remarked that Professor Mackintosh had informed him that although he did not take away the (small) specimen that he had seen lying on the shore at North Strand (during August 1883) he was “morally certain that his identification was correct”. Haddon noted that although there were no specimens to support either Macalister and McNab’s (1878) or Mackintosh’s (1884) reports, there was a (single) specimen of O. vulgaris in the Museum of Trinity College, Dublin, labelled “Dublin Bay” which was said to have been presented by the late Mr Goode. Later, Rees (1950) noted that while all of the old Irish records were doubtful, two specimens preserved in the Museum of Trinity College labelled “Dublin Bay” were examined by Massy (1909, 1928) who confirmed that they were O. vulgaris. The latter two specimens, both of similar size (c.15cm TL), were recently re-examined by Dr Julia Nunn (pers. comm.) and subsequently by DQ and both confirmed the identity as O. vulgaris. Although no further details are available on these specimens (Dr Martyn Linnie pers. comm.), there is no reason to doubt the authenticity of their provenance. Holt (1892) reported having captured O. vulgaris in a beam trawl at a depth of 440 m, 64 km off Achill Head, Co. Mayo on 4 July 1890. According to Boyle and Rodhouse (2005) and Roper et al. (1984), O. vulgaris is found from the shoreline down to depths of about 400 m (off NW Africa), but is most abundant between 15 and 100 m on all types of sea bed. Since Holt’s

specimen was captured outside the maximum reported depth range for O. vulgaris, it is possible that it may have been E. cirrhosa which has been reported from depths of about 500 m (Roper et al. 1984, Collins et al. 2001) or indeed, some other species of deep-water octopod. O. vulgaris attains a maximum TL of 130 cm and a weight of 10 kg. In the western Mediterranean, mantle length at first maturity is about 9.5 cm in males and 13.5 cm in females (Roper et al. 1984). The distribution of O. vulgaris in Irish waters has recently been described as “occasionally found in rock pools at very low tides off rocky coasts around Ireland” (Sterry 2010), without any reference to the occurrence of E. cirrhosa. Indeed, in a recent issue of definitive Irish postage stamps featuring various species of marine fauna, An Post (2010) included O. vulgaris but not E. cirrhosa. Viney and Viney (2008) mentioned that O. vulgaris “is found mainly off Ireland’s south coast, whereas E. cirrhosa is found all around the island”. Seaward (1990) included the W and SW of Ireland in his review of the distribution of O. vulgaris in northern European waters but did not provide any specific references for authenticated records from Irish waters. Henderson and Dunne (2002) noted that small (mean mantle length, 5.0 cm), mostly whole, O. vulgaris were the second most important prey species in the stomach contents of Spiny Dogfish (Squalus acanthias Linnaeus, 1758) captured off the W (and SW) coast of Ireland while E. cirrhosa, identified from three beaks, were only of minor importance. Although O. vulgaris has been recorded more frequently in UK waters, it has never been recorded as prey in the diet of any elasmobranch species (Dr Jim Ellis pers. comm.). E. cirrhosa was only of minor importance in the diet of S. acanthias, Lesser

Spotted Dogfish (Scyliorhinus canicula (Linnaeus, 1758)), Thornback Ray (Raja clavata Linnaeus, 1758) and Blonde Ray (R. brachyura Lafont, 1873) but was the single most important prey species of Tope (Galeorhinus galeus (Linnaeus, 1758)) and the second most important in Greater Spotted Dogfish (S. stellaris (Linnaeus, 1758)) (Ellis et al. 1996). E. cirrhosa beaks were also found in the stomach of a juvenile six-gill shark (Hexanchus griseus (Bonnaterre, 1788)) captured off Inishbofin Island, Co. Galway during September 1986 (Quigley and Flannery unpublished data, NMINH:1991.43.1). It is interesting to note that cephalopod beaks, which are mainly composed of keratin, have not been recorded from archaeological sites in either the UK or Ireland (Dr Sheila Hamilton-Dyer pers. comm.). During the 1990s, O. vulgaris was not recorded during extensive offshore demersal trawl surveys off the west coast of Ireland and in the Celtic Sea (Lordan et al. 2001) or during recent major littoral and sublittoral surveys of marine species and habitats of Ireland (Picton and Morrow 2006, Nunn et al. 2005, Nunn 2009). Although O. vulgaris has been recorded on one occasion from as far north as Sweden (GBIF 2013, specimen SMNH:EV:15345), and only occasionally from the North Sea (Seaward 1990), the species has rarely been recorded further north than south-western Britain and the western English Channel, where its abundance varies from year to year (Hayward 2003). Periodic ‘plagues’ associated with higher than normal sea water temperatures (Garstang 1900, Rees, 1950, Rees and Lumby 1954) and mass mortalities associated with particularly severe winters (Woodhead 1964) have been recorded on the UK side of the English Channel. It is interesting Irish Naturalists’ Journal Vol. 33 Part 2   125

Common Octopus in Irish waters

The Common Octopus (Octopus vulgaris Cuvier) in Irish waters

Figure 1. Large specimen of the Common Octopus (Octopus vulgaris) caught in Dingle Bay, Co. Kerry.

*Declan T.G. Quigley and Kevin Flannery

Dingle Oceanworld (Mara Beo Teo), The Wood, Dingle, Co. Kerry The third authenticated record of the Common Octopus (Octopus vulgaris Cuvier) is reported from Irish waters and the species status is reviewed in terms of both historical and recent information. It was concluded that O. vulgaris has been, and continues to be, frequently confused with the more commonly occurring Lesser Octopus ((Eledone cirrhosa (Lamarck)) and that O. vulgaris is currently rare in Irish waters. Keywords: Octopus vulgaris, Eledone cirrhosa, Irish records On 28 March 2005, the MFV Elsie Maria II (T114) [Skipper: David Granville, Dingle], captured a large specimen of the Common Octopus (Octopus vulgaris Cuvier, 1797) while trawling in Dingle Bay (c.520 04’N, 100 20’W), Co. Kerry, SW Ireland (Fig. 1). The following morphometric details were recorded: total length, 103 cm; mantle length 21cm; maximum length from tip of beak to tip of arms 89 cm; maximum arm span 160cm; weight 3.75kg. There were two longitudinal rows of suckers on each arm. The current specimen, which is the third authenticated record of O. vulgaris from Irish waters, was donated to the National Museum of Ireland (NMINH:2007.25.1). Octopus vulgaris is generally considered cosmopolitan, nominally with global distribution in temperate and tropical waters (Roper et al. 1984). It is a species complex awaiting full description within which the historically designated species has a distribution centred on the Mediterranean (Mangold and Hochberg 1991, Mangold 1998). However, recent genetic evidence has shown that the species is also present on both sides of the Atlantic and Indian Oceans including South Africa, Amsterdam and Saint Paul Islands, Taiwan and Japan (see Guerra et al. 2010 and references therein). Historically, the occurrence of O. vulgaris in Irish waters has been described as “not uncommon”. However, Thompson (1856) and Nichols (1900) were of the opinion that these probably referred to the Lesser Octopus (Eledone cirrhosa (Lamarck, 1798)) which is known to be common all around the Irish coast (Gibson et al. 2001, Dr Julia Nunn pers. comm.) and in offshore waters down to depths of 490 m (Collins et al. 2001). Elsewhere in the north*Corresponding author – [email protected] 124  Irish Naturalists’ Journal Vol. 33 Part 2

east Atlantic, E. cirrhosa ranges from Iceland (to 670N) southwards to the Mediterranean (Roper et al. 1984). Haddon (1886) expressed doubts about the authenticity of specimens of O. vulgaris reported from Bray, Co Wicklow (Macalister and McNab 1878) and North Strand, Dublin Bay (Mackintosh 1884). However, he remarked that Professor Mackintosh had informed him that although he did not take away the (small) specimen that he had seen lying on the shore at North Strand (during August 1883) he was “morally certain that his identification was correct”. Haddon noted that although there were no specimens to support either Macalister and McNab’s (1878) or Mackintosh’s (1884) reports, there was a (single) specimen of O. vulgaris in the Museum of Trinity College, Dublin, labelled “Dublin Bay” which was said to have been presented by the late Mr Goode. Later, Rees (1950) noted that while all of the old Irish records were doubtful, two specimens preserved in the Museum of Trinity College labelled “Dublin Bay” were examined by Massy (1909, 1928) who confirmed that they were O. vulgaris. The latter two specimens, both of similar size (c.15cm TL), were recently re-examined by Dr Julia Nunn (pers. comm.) and subsequently by DQ and both confirmed the identity as O. vulgaris. Although no further details are available on these specimens (Dr Martyn Linnie pers. comm.), there is no reason to doubt the authenticity of their provenance. Holt (1892) reported having captured O. vulgaris in a beam trawl at a depth of 440 m, 64 km off Achill Head, Co. Mayo on 4 July 1890. According to Boyle and Rodhouse (2005) and Roper et al. (1984), O. vulgaris is found from the shoreline down to depths of about 400 m (off NW Africa), but is most abundant between 15 and 100 m on all types of sea bed. Since Holt’s

specimen was captured outside the maximum reported depth range for O. vulgaris, it is possible that it may have been E. cirrhosa which has been reported from depths of about 500 m (Roper et al. 1984, Collins et al. 2001) or indeed, some other species of deep-water octopod. O. vulgaris attains a maximum TL of 130 cm and a weight of 10 kg. In the western Mediterranean, mantle length at first maturity is about 9.5 cm in males and 13.5 cm in females (Roper et al. 1984). The distribution of O. vulgaris in Irish waters has recently been described as “occasionally found in rock pools at very low tides off rocky coasts around Ireland” (Sterry 2010), without any reference to the occurrence of E. cirrhosa. Indeed, in a recent issue of definitive Irish postage stamps featuring various species of marine fauna, An Post (2010) included O. vulgaris but not E. cirrhosa. Viney and Viney (2008) mentioned that O. vulgaris “is found mainly off Ireland’s south coast, whereas E. cirrhosa is found all around the island”. Seaward (1990) included the W and SW of Ireland in his review of the distribution of O. vulgaris in northern European waters but did not provide any specific references for authenticated records from Irish waters. Henderson and Dunne (2002) noted that small (mean mantle length, 5.0 cm), mostly whole, O. vulgaris were the second most important prey species in the stomach contents of Spiny Dogfish (Squalus acanthias Linnaeus, 1758) captured off the W (and SW) coast of Ireland while E. cirrhosa, identified from three beaks, were only of minor importance. Although O. vulgaris has been recorded more frequently in UK waters, it has never been recorded as prey in the diet of any elasmobranch species (Dr Jim Ellis pers. comm.). E. cirrhosa was only of minor importance in the diet of S. acanthias, Lesser

Spotted Dogfish (Scyliorhinus canicula (Linnaeus, 1758)), Thornback Ray (Raja clavata Linnaeus, 1758) and Blonde Ray (R. brachyura Lafont, 1873) but was the single most important prey species of Tope (Galeorhinus galeus (Linnaeus, 1758)) and the second most important in Greater Spotted Dogfish (S. stellaris (Linnaeus, 1758)) (Ellis et al. 1996). E. cirrhosa beaks were also found in the stomach of a juvenile six-gill shark (Hexanchus griseus (Bonnaterre, 1788)) captured off Inishbofin Island, Co. Galway during September 1986 (Quigley and Flannery unpublished data, NMINH:1991.43.1). It is interesting to note that cephalopod beaks, which are mainly composed of keratin, have not been recorded from archaeological sites in either the UK or Ireland (Dr Sheila Hamilton-Dyer pers. comm.). During the 1990s, O. vulgaris was not recorded during extensive offshore demersal trawl surveys off the west coast of Ireland and in the Celtic Sea (Lordan et al. 2001) or during recent major littoral and sublittoral surveys of marine species and habitats of Ireland (Picton and Morrow 2006, Nunn et al. 2005, Nunn 2009). Although O. vulgaris has been recorded on one occasion from as far north as Sweden (GBIF 2013, specimen SMNH:EV:15345), and only occasionally from the North Sea (Seaward 1990), the species has rarely been recorded further north than south-western Britain and the western English Channel, where its abundance varies from year to year (Hayward 2003). Periodic ‘plagues’ associated with higher than normal sea water temperatures (Garstang 1900, Rees, 1950, Rees and Lumby 1954) and mass mortalities associated with particularly severe winters (Woodhead 1964) have been recorded on the UK side of the English Channel. It is interesting Irish Naturalists’ Journal Vol. 33 Part 2   125

Quigley, D.T.G and Flannery, K.

to note that Thompson (1856) remarked that great numbers of E. cirrhosa were cast ashore at Youghal, Co. Cork after a snow-storm in 1838. Large numbers of E. cirrhosa and other marine fauna were recently washed up in Dundalk Bay, Co. Louth, following a major storm during March 2013 (Declan MacGabhann pers. comm.). Brown (1878) mentioned that O. vulgaris had been recorded, albeit rarely, from the Firth of Clyde (SW Scotland). Seaward (1990) indicated the occurrence of O. vulgaris on the UK side of the Irish Sea, specifically from Liverpool Bay and the Bristol Channel. Additional records from the UK side of the Irish Sea, including Cumbria, Isle of Man and Lleyn Peninsula, Caernarvonshire (Wales), were indicated on a recent map published by the Conchological Society of Great Britain and Ireland (2013). However, Bruce et al. (1963) only reported E. cirrhosa from the Isle of Man and its surrounding seas. Rees (1950) and Rees and Lumby (1954) discovered O. vulgaris pelagic larvae of various sizes, ranging from newly hatched to 6 mm (mantle length), in plankton hauls north of the Channel Islands. They concluded that since there was no indication of substantial breeding on the English coast, that these larvae were derived from breeding centres on the coast of Brittany and the Channel Islands and that the influx of larvae, influenced by the vagaries of water movements within the English Channel each year, probably accounted for the fluctuations in the abundance of the species in UK waters. It is possible that the same factors may also account for the occasional immigration of O. vulgaris into Irish waters. Indeed, the trend of increasing temperatures in Irish sea waters during recent decades (Boelens et al. 2005) may facilitate an increase in the abundance of O. vulgaris. It is interesting to note that several large specimens of O. vulgaris have recently been recorded from the English Channel and southern North Sea (British Marine Life Study Society 2013). Although E. cirrhosa is the species of octopus most commonly found in Irish waters, it is possible that O. vulgaris may occur more frequently than the current paucity of authenticated records would suggest, particularly along the south coast. O. vulgaris and E. cirrhosa, especially small specimens, are both superficially very similar in appearance, but on closer examination they can easily be distinguished by the presence of two rows of longitudinal suckers on each arm of O. vulgaris and a single row in E. cirrhosa. Acknowledgements We are grateful to Dr Martyn Linnie (Department of Zoology, School of Natural Sciences, 126  Irish Naturalists’ Journal Vol. 33 Part 2

Common Octopus in Irish waters

Trinity College, Dublin 2) for his assistance in examining the specimens of O. vulgaris in the collections of the Zoological Museum, Trinity College, Mr Nigel Monaghan (National Museum of Ireland – Natural History, Dublin 2) for information on NMI specimens, Dr Julia Nunn (National Museums of Northern Ireland, Cultra, Hollywood, Co. Down) for her expert advice and comments on the draft manuscript, Dr Sheila Hamilton-Dyer (SHD ArchaeoZoology)) for her expert advice in relation to archaeocephalopod remains, Dr Jim Ellis (CEFAS, UK) for information on the cephalopod prey of elasmobranchs in UK waters, Mr Declan MacGabhann (Sea Fisheries Protection Authority, Howth, Co. Dublin) for information on recent storm-stranded marine fauna in Dundalk Bay, and Professor Tom Bolger (Department of Zoology, University College, Dublin 4) for his helpful comments on the manuscript. References An Post (2010) Definitive Stamps - Irish Animals and Marine Life. Online at: www.irishstamps. ie Boelens, R., Minchin, D. and O’Sullivan, G. (2005) Climatic Change: Implications for Ireland’s Marine Environment and Resources. Marine Foresight Series No. 2, Marine Institute, Galway, Ireland. Boyle, P. and Rodhouse, P. (2005) Cephalopods: Ecology and Fisheries. Blackwell Science, UK. British Marine Life Study Society (2013) Octopuses & other Cephalopods. Online at: http://www.glaucus.org.uk/Octopus.htm Brown, A. (1878) The Mollusca of the Firth of Clyde, being a catalogue of recent marine species found in that estuary. Hugh Hopkins, Glasgow. Bruce, J.R., Colman, J.S. and Jones, N.S. (1963) Marine Fauna of the Isle of Man and its surrounding seas. Liverpool University Press. Collins, M.A., Yau, C., Allcock, L. and Thurston, M.H. (2001) Distribution of deep-water benthic and bentho-pelagic cephalopods from the north-east Atlantic. Journal of the Marine Biological Association of the United Kingdom 81: 105-117. Conchological Society of Great Britain and Ireland (2013) Encyclopedia. Online at: http://www.conchsoc.org/spAccount/ octopus-vulgaris Ellis, J.R., Pawson, M.G. and Shackley, S.E. (1996) The comparative feeding ecology of six species of shark and four species of ray (Elasmobranchii) in the North-East Atlantic. Journal of the Marine Biological Association of the United Kingdom 76: 89-106. Garstang, W. (1900) The plague of Octopus on

the South Coast and its effects on the crab and lobster fisheries. Journal of the Marine Biological Association of the United Kingdom 6: 260-273. Gibson, R., Hextall, B. and Rogers, A. (2001) Photographic Guide to the Sea & Shore Life of Britain & North-West Europe. Oxford University Press, UK. GBIF (2013) Global Biodiversity Information Facility. Online at: http://data.gbif.org Guerra, A., Roura, A., Gonzalez, A.F., Pascual, S., Cherel, Y. and Perez-Losada, M. (2010) Morphological and genetic evidence that Octopus vulgaris Cuvier, 1797 inhabits Amsterdam and Saint Paul Islands (southern Indian Ocean). ICES Journal of Marine Science 67: 1401-1407. Haddon, A.C. (1886) Recent contributions to the marine invertebrate fauna of Ireland. Zoologist, Series 3, 10 (109): 1-7. Hayward, P.J. (2003) Mollusca II: Bivalva and Cephalopoda. In: Hayward, P.J. and Ryland, J.S. (eds.) The Marine Fauna of the British Isles and North-West Europe. 2: 731-793. Clarendon Press, Oxford, UK. Henderson, A.C. and Dunne, J. (2002) Stomach contents of spiny dogfish Squalus acanthias L. off the west coast of Ireland. Irish Naturalists’ Journal 27: 101-105. Holt, E.W.L. (1892) Survey of fishing grounds, west coast of Ireland, 1890-91. Report on the results of the fishing operations. Scientific Proceedings of the Royal Dublin Society (New Series) 7: 225-387. Lordan, C., Warnes, S., Cross, T. and Burnell, G. (2001) The distribution and abundance of cephalopod species caught during demersal trawl surveys west of Ireland and in the Celtic Sea. Irish Fisheries Investigations No. 8. 26pp. Macalister, A. and McNab, W.R. (1878) British Association meeting in Dublin, 1878. Guide to the county of Dublin: its geology, industries, flora and fauna. Hodges, Foster & Figgis, Dublin. Mackintosh, H.W. (1884) Report on the Irish Zoophytes – Part 1. On some rare sea anemones taken at Greystones, Co. Wicklow, with remarks on the marine invertebrate fauna of that district. Proceedings of the Royal Irish Academy Series 2, 4 (5): 52-58. Mangold, K. (1998) The Octopodinae from the Eastern Atlantic Ocean and the Mediterranean Sea. In Voss, N.A., Vecchione, M., Toll, R.B. and Sweeney, M.J. (eds.). Systematics and Biogeography of Cephalopods. 2: 521-528. Smithsonian Institution Press, Washington. Mangold, K. and Hochberg, F.G. (1991) Abstract: Defining the genus Octopus, redescription of Octopus vulgaris. Bulletin of Marine Science 49: 665.

Massy, A.L. (1909) The Cephalopoda dibranchiata of the coast of Ireland. Fisheries Ireland Scientific Investigations (Series 1907, Part 1): 1-39. Massy, A.L. (1928) The Cephalopoda of the Irish coast. Proceedings of the Royal Irish Academy. Section B; Biological, Geological and Chemical Science 38 (1928/1929): 25-37. Nichols, A.R. (1900) A list of the marine mollusca of Ireland (Report from the Fauna and Flora Committee). Proceedings of the Royal Irish Academy (1889-1901), 5 (1898-1900): 477-662. Nunn, J. (2009) Mapping the marine molluscs of Ireland. Bulletin of the National Biodiversity Data Centre. Issue 3 (Spring 2009), pp 5-6. Nunn, J.D., Smith, S.M., Picton, B.E. and McGrath, D. (2005) A checklist, atlas and bibliography for the marine mollusca of Ireland. In Wilson, J.G. (ed.) The Intertidal Ecosystem: The Value of Ireland’s Shores: 200201. Royal Irish Academy, Dublin. Picton, B.E. and Morrow, C.C. (2006) BioMar Survey of marine species and habitats of Ireland. Ulster Museum, Belfast. Online at: www. habitas.org/marinelife/biomarpages/about. htm Rees, W.J. (1950) The distribution of Octopus vulgaris Lamarck in British waters. Journal of the Marine Biological Association of the United Kingdom 29: 361-378. Rees, W.J. and Lumby, J.R. (1954) The abundance of Octopus in the English Channel. Journal of the Marine Biological Association of the United Kingdom 33: 515-536. Roper, C.F.E., Sweeney, M.J. and Nauen, C.E. (1984) FAO Species Catalogue Volume 3. Cephalopods of the world. An annotated and illustrated catalogue of species of interest to fisheries. FAO Fisheries Synopsis No. 125, 3. FAO, Rome. Seaward, D.R. (1990) Distribution of the marine molluscs of north west Europe. Nature Conservancy Council and Conchological Society of Great Britain and Ireland. Sterry, P. (2010) Collins Complete Guide to Irish Wildlife. HarperCollins, London. Thompson, W. (1856) The Natural History of Ireland. 4: 203-205. Henry G. Bohn, London. Woodhead, P.M.J. (1964) The death of fish and sub-littoral fauna in the North Sea and the English Channel during the winter of 196263. In D.J. Crisp (Ed) The effects of the severe winter of 1962-63 on marine life in Britain. Journal of Animal Ecology 33 (1): 165-210. Viney, M. and Viney, E. (2008) Ireland’s Ocean – A Natural History. The Collins Press, Cork. Irish Naturalists’ Journal Vol. 33 Part 2   127

Quigley, D.T.G and Flannery, K.

to note that Thompson (1856) remarked that great numbers of E. cirrhosa were cast ashore at Youghal, Co. Cork after a snow-storm in 1838. Large numbers of E. cirrhosa and other marine fauna were recently washed up in Dundalk Bay, Co. Louth, following a major storm during March 2013 (Declan MacGabhann pers. comm.). Brown (1878) mentioned that O. vulgaris had been recorded, albeit rarely, from the Firth of Clyde (SW Scotland). Seaward (1990) indicated the occurrence of O. vulgaris on the UK side of the Irish Sea, specifically from Liverpool Bay and the Bristol Channel. Additional records from the UK side of the Irish Sea, including Cumbria, Isle of Man and Lleyn Peninsula, Caernarvonshire (Wales), were indicated on a recent map published by the Conchological Society of Great Britain and Ireland (2013). However, Bruce et al. (1963) only reported E. cirrhosa from the Isle of Man and its surrounding seas. Rees (1950) and Rees and Lumby (1954) discovered O. vulgaris pelagic larvae of various sizes, ranging from newly hatched to 6 mm (mantle length), in plankton hauls north of the Channel Islands. They concluded that since there was no indication of substantial breeding on the English coast, that these larvae were derived from breeding centres on the coast of Brittany and the Channel Islands and that the influx of larvae, influenced by the vagaries of water movements within the English Channel each year, probably accounted for the fluctuations in the abundance of the species in UK waters. It is possible that the same factors may also account for the occasional immigration of O. vulgaris into Irish waters. Indeed, the trend of increasing temperatures in Irish sea waters during recent decades (Boelens et al. 2005) may facilitate an increase in the abundance of O. vulgaris. It is interesting to note that several large specimens of O. vulgaris have recently been recorded from the English Channel and southern North Sea (British Marine Life Study Society 2013). Although E. cirrhosa is the species of octopus most commonly found in Irish waters, it is possible that O. vulgaris may occur more frequently than the current paucity of authenticated records would suggest, particularly along the south coast. O. vulgaris and E. cirrhosa, especially small specimens, are both superficially very similar in appearance, but on closer examination they can easily be distinguished by the presence of two rows of longitudinal suckers on each arm of O. vulgaris and a single row in E. cirrhosa. Acknowledgements We are grateful to Dr Martyn Linnie (Department of Zoology, School of Natural Sciences, 126  Irish Naturalists’ Journal Vol. 33 Part 2

Common Octopus in Irish waters

Trinity College, Dublin 2) for his assistance in examining the specimens of O. vulgaris in the collections of the Zoological Museum, Trinity College, Mr Nigel Monaghan (National Museum of Ireland – Natural History, Dublin 2) for information on NMI specimens, Dr Julia Nunn (National Museums of Northern Ireland, Cultra, Hollywood, Co. Down) for her expert advice and comments on the draft manuscript, Dr Sheila Hamilton-Dyer (SHD ArchaeoZoology)) for her expert advice in relation to archaeocephalopod remains, Dr Jim Ellis (CEFAS, UK) for information on the cephalopod prey of elasmobranchs in UK waters, Mr Declan MacGabhann (Sea Fisheries Protection Authority, Howth, Co. Dublin) for information on recent storm-stranded marine fauna in Dundalk Bay, and Professor Tom Bolger (Department of Zoology, University College, Dublin 4) for his helpful comments on the manuscript. References An Post (2010) Definitive Stamps - Irish Animals and Marine Life. Online at: www.irishstamps. ie Boelens, R., Minchin, D. and O’Sullivan, G. (2005) Climatic Change: Implications for Ireland’s Marine Environment and Resources. Marine Foresight Series No. 2, Marine Institute, Galway, Ireland. Boyle, P. and Rodhouse, P. (2005) Cephalopods: Ecology and Fisheries. Blackwell Science, UK. British Marine Life Study Society (2013) Octopuses & other Cephalopods. Online at: http://www.glaucus.org.uk/Octopus.htm Brown, A. (1878) The Mollusca of the Firth of Clyde, being a catalogue of recent marine species found in that estuary. Hugh Hopkins, Glasgow. Bruce, J.R., Colman, J.S. and Jones, N.S. (1963) Marine Fauna of the Isle of Man and its surrounding seas. Liverpool University Press. Collins, M.A., Yau, C., Allcock, L. and Thurston, M.H. (2001) Distribution of deep-water benthic and bentho-pelagic cephalopods from the north-east Atlantic. Journal of the Marine Biological Association of the United Kingdom 81: 105-117. Conchological Society of Great Britain and Ireland (2013) Encyclopedia. Online at: http://www.conchsoc.org/spAccount/ octopus-vulgaris Ellis, J.R., Pawson, M.G. and Shackley, S.E. (1996) The comparative feeding ecology of six species of shark and four species of ray (Elasmobranchii) in the North-East Atlantic. Journal of the Marine Biological Association of the United Kingdom 76: 89-106. Garstang, W. (1900) The plague of Octopus on

the South Coast and its effects on the crab and lobster fisheries. Journal of the Marine Biological Association of the United Kingdom 6: 260-273. Gibson, R., Hextall, B. and Rogers, A. (2001) Photographic Guide to the Sea & Shore Life of Britain & North-West Europe. Oxford University Press, UK. GBIF (2013) Global Biodiversity Information Facility. Online at: http://data.gbif.org Guerra, A., Roura, A., Gonzalez, A.F., Pascual, S., Cherel, Y. and Perez-Losada, M. (2010) Morphological and genetic evidence that Octopus vulgaris Cuvier, 1797 inhabits Amsterdam and Saint Paul Islands (southern Indian Ocean). ICES Journal of Marine Science 67: 1401-1407. Haddon, A.C. (1886) Recent contributions to the marine invertebrate fauna of Ireland. Zoologist, Series 3, 10 (109): 1-7. Hayward, P.J. (2003) Mollusca II: Bivalva and Cephalopoda. In: Hayward, P.J. and Ryland, J.S. (eds.) The Marine Fauna of the British Isles and North-West Europe. 2: 731-793. Clarendon Press, Oxford, UK. Henderson, A.C. and Dunne, J. (2002) Stomach contents of spiny dogfish Squalus acanthias L. off the west coast of Ireland. Irish Naturalists’ Journal 27: 101-105. Holt, E.W.L. (1892) Survey of fishing grounds, west coast of Ireland, 1890-91. Report on the results of the fishing operations. Scientific Proceedings of the Royal Dublin Society (New Series) 7: 225-387. Lordan, C., Warnes, S., Cross, T. and Burnell, G. (2001) The distribution and abundance of cephalopod species caught during demersal trawl surveys west of Ireland and in the Celtic Sea. Irish Fisheries Investigations No. 8. 26pp. Macalister, A. and McNab, W.R. (1878) British Association meeting in Dublin, 1878. Guide to the county of Dublin: its geology, industries, flora and fauna. Hodges, Foster & Figgis, Dublin. Mackintosh, H.W. (1884) Report on the Irish Zoophytes – Part 1. On some rare sea anemones taken at Greystones, Co. Wicklow, with remarks on the marine invertebrate fauna of that district. Proceedings of the Royal Irish Academy Series 2, 4 (5): 52-58. Mangold, K. (1998) The Octopodinae from the Eastern Atlantic Ocean and the Mediterranean Sea. In Voss, N.A., Vecchione, M., Toll, R.B. and Sweeney, M.J. (eds.). Systematics and Biogeography of Cephalopods. 2: 521-528. Smithsonian Institution Press, Washington. Mangold, K. and Hochberg, F.G. (1991) Abstract: Defining the genus Octopus, redescription of Octopus vulgaris. Bulletin of Marine Science 49: 665.

Massy, A.L. (1909) The Cephalopoda dibranchiata of the coast of Ireland. Fisheries Ireland Scientific Investigations (Series 1907, Part 1): 1-39. Massy, A.L. (1928) The Cephalopoda of the Irish coast. Proceedings of the Royal Irish Academy. Section B; Biological, Geological and Chemical Science 38 (1928/1929): 25-37. Nichols, A.R. (1900) A list of the marine mollusca of Ireland (Report from the Fauna and Flora Committee). Proceedings of the Royal Irish Academy (1889-1901), 5 (1898-1900): 477-662. Nunn, J. (2009) Mapping the marine molluscs of Ireland. Bulletin of the National Biodiversity Data Centre. Issue 3 (Spring 2009), pp 5-6. Nunn, J.D., Smith, S.M., Picton, B.E. and McGrath, D. (2005) A checklist, atlas and bibliography for the marine mollusca of Ireland. In Wilson, J.G. (ed.) The Intertidal Ecosystem: The Value of Ireland’s Shores: 200201. Royal Irish Academy, Dublin. Picton, B.E. and Morrow, C.C. (2006) BioMar Survey of marine species and habitats of Ireland. Ulster Museum, Belfast. Online at: www. habitas.org/marinelife/biomarpages/about. htm Rees, W.J. (1950) The distribution of Octopus vulgaris Lamarck in British waters. Journal of the Marine Biological Association of the United Kingdom 29: 361-378. Rees, W.J. and Lumby, J.R. (1954) The abundance of Octopus in the English Channel. Journal of the Marine Biological Association of the United Kingdom 33: 515-536. Roper, C.F.E., Sweeney, M.J. and Nauen, C.E. (1984) FAO Species Catalogue Volume 3. Cephalopods of the world. An annotated and illustrated catalogue of species of interest to fisheries. FAO Fisheries Synopsis No. 125, 3. FAO, Rome. Seaward, D.R. (1990) Distribution of the marine molluscs of north west Europe. Nature Conservancy Council and Conchological Society of Great Britain and Ireland. Sterry, P. (2010) Collins Complete Guide to Irish Wildlife. HarperCollins, London. Thompson, W. (1856) The Natural History of Ireland. 4: 203-205. Henry G. Bohn, London. Woodhead, P.M.J. (1964) The death of fish and sub-littoral fauna in the North Sea and the English Channel during the winter of 196263. In D.J. Crisp (Ed) The effects of the severe winter of 1962-63 on marine life in Britain. Journal of Animal Ecology 33 (1): 165-210. Viney, M. and Viney, E. (2008) Ireland’s Ocean – A Natural History. The Collins Press, Cork. Irish Naturalists’ Journal Vol. 33 Part 2   127