Fig. 1

Distribution map of the extant deep-water squid S. spirula. Dark grey areas indicate live catches and thus the habitat of S. spirula. Light grey regions mark shells found drifting, washed ashore on beaches, and fishery bycatch. Dashed areas mark the possible, supposed or expected primary habitats, see text for explanation. Numbers 1–12 correspond to sites represented in the present comparative analysis. Atlantic Ocean: 1 Canary Islands, North Atlantic Ocean, South Spain, 2 Porto Santo, North Atlantic Ocean, South Portugal, 3 Tobago, Caribbean Sea, Trinidad & Tobago, 4 Salvador, East Brazil, South Atlantic Ocean, 5 Pater Noster Beach, South Atlantic Ocean, western South Africa. Indian Ocean: 6 var. localities, Indian Ocean, East Tanzania, 7 Mauritius, Indian Ocean, Republic of Mauritius, 8 var. localities Maldives, Laccadive Sea, Republic of the Maldives, 9 South-western Sri Lanka, Laccadive Sea, Republic of Sri Lanka, 10 Phuket, Andaman Sea, South Thailand. 11 Conspicuous Cliff & Sorrento Beach, South Indian Ocean, western Australia. Pacific Ocean: 12 Avalon Beach, Tasman Sea, eastern Australia. Distribution map compiled from literature and own data and modified after Schmidt (1922), Bruun (1943, 1955), Clarke (1966), Goud (1985), Nesis (1987, 1991), Joubin (1995), Reid (2005), Norman (2007), Lukeneder et al. (2008). For comparison see also Okutani (1995), Haimovici et al. (2007), Neige and Warnke (2010), Haring et al. (2012), and Hoffmann and Warnke (2014). Marine regions were classified in accordance with Claus et al. (2014a, b). For further details of specimen sites, see Table 1