239 The Technical Details 240 The Technical Details The Cephalopod Family Tree Mollusca (molluscs) is a phylum within the animal king- dom (Animalia). Cephalopods are a class of Mollusca and they are themselves divided into two sub-classes, Nautiloidea (nautiluses) and Coleoidea (true cephalopods). Coleoidea are also sorted into two groups, Belemnoidea, which are extinct, and Neocoleoidea, which encompasses all present-day cephalopods. Neocoleoidea are also divided into two superorders, Decapodiformes (cephalopods with eight arms and two tentacles) and Octopodiformes (cepha- lopods with eight arms). There are four orders of Decapodiformes: Spirulida (extinct), Sepioidea (cuttlefsh), Oegopsida (squid), and Myopsida (squid). There are two orders of Octopodiformes: Vampyromorphida, and Octopoda (octopuses). This book deals primarily with Sepioidea, Oegopsida, Myopsida, and Octopoda. Animalia Mollusca Cephalopoda Coleoidea (true cephalopods) Nautiloidea †Belemnoidea Neocoleoidea Nautilida Decapodiformes Octopodiformes Spirulida SepioideaOegopsida Myopsida Octopoda Vampyromorpha (cuttlesh) (squid) (squid) (octopuses) Cephalopods Included in This Book The table lists the cephalopods that are discussed in this book according to the name of their species, together with the common English names. In addition, there is a nota- tion of whether a species can, in principle, be used for human consumption, even though it may not be common to do so or to catch it. The right hand column indicates where that species is usually found. 241 The Technical Details Latin name English name Edible? Primary distribution Alloteuthis subulata S European common squid Yes Eastern North Atlantic Ocean Architeuthis dux S North Atlantic squid No All oceans, but rare in tropical and polar latitudes Argonauta sp. Argonaut, paper nautilus Yes Tropical and subtropical waters worldwide Callistoctopus O White-spotted octopus Yes Mediterranean Sea, macropus warmer parts of Atlantic Ocean, Caribbean Sea, Indo-Pacifc Ocean Dosidicus gigas S Jumbo fying squid, Yes Eastern Pacifc Ocean Humboldt squid from Tierra del Fuego to California Eledone cirrhosa O Curled octopus, horned Yes Eastern North Atlantic octopus Ocean, Mediterranean Sea Enteroctopus dofeini O North Pacifc giant Yes Coastal North Pacifc octopus Ocean Euprymna scolopes C Hawaiian bobtail squid No Pacifc Ocean Grimpoteuthis sp. O Dumbo octopus No All oceans, but at great depths Hapalochlaena spp. O Southern blue-ringed No Indo-Pacifc Ocean octopus (blue- ringed octopus are found as far north as Japan) Idiosepius thailandicus C Bobtail squid, pygmy No Indo-Pacifc Ocean squid Illex argentinus S Argentine shortfn squid Yes Southwestern Atlantic Ocean Loligo forbesii S Veined squid, Yes Eastern North Atlantic long-fnned squid Ocean, Mediterranean Sea, Red Sea, Western Indian Ocean 242 The Technical Details Latin name English name Edible? Primary distribution Loligo pealei S Longfn inshore squid Yes North Atlantic Ocean Loligo vulgaris S European squid Yes Coastal waters of the eastern North Atlantic Ocean Mesonychoteuthis S Colossal squid, Antarctic Yes All parts of the hamiltoni squid, giant cranch squid Southern Ocean Nautilus sp. Nautilus Yes Indo-Pacifc Ocean Octopus maya O Mexican four-eyed Yes Tropical Western octopus Atlantic Ocean Octopus vulgaris O Common octopus Yes Atlantic Ocean, Indian Ocean, Pacifc Ocean Octopus wolf O Star-sucker pygmy No Western Pacifc Ocean octopus Sepia offcinalis C Common cuttlefsh, Yes Mediterranean Sea, European common North Sea, Baltic Sea cuttlefsh Sepietta oweniana C Common bobtail Yes Eastern North Atlantic Ocean, Mediterranean Sea Sepiola spp. C Bobtail squid Yes All oceans Taningia danae S Dana octopus squid, Yes Atlantic Ocean, Pacifc Taning’s octopus squid Ocean, but very rare Todarodes pacifcus S Japanese fying squid, Yes Northern Pacifc Japanese common squid, Ocean Pacifc fying squid Todarodes sagittatus S European fying squid Yes Northeastern Atlantic Ocean, Mediterranean Sea Thaumoctopus mimicus O Mimic octopus No Indo-Pacifc Ocean Watasenia scintillans S Firefy squid, sparkling Yes Western Pacifc Ocean enope squid C cuttlefsh, O octopus, S squid 243 Glossary Glossary ambergris - a special secretion that is formed in the intes- tines of the sperm whale in the shape of grey rock-like lumps that can weigh up to several hundred kilograms and often contain the remains of cephalopods; known since ancient times as a fxative in perfumes and for its fragrance. Animalia - the animal kingdom. anisakis - parasitic nematode (herring worm) that can infest certain fsh and cephalopods. adenosine triphosphate - (adenosine-5'-triphosphate, ATP) polynucleotide that is the biochemical source of energy production in living cells. Among other sub- stances, it can be broken down to the 5'-ribonucleotides inosinate, adenylate, and guanylate, which are associated with synergistic umami. adenosine monophosphate - (AMP), a salt of the nucleic acid adenylic acid; synergizes with glutamate to enhance umami; found especially in fsh, shellfsh, and octopuses. alcatruz - pot used to catch octopuses in the traditional way by Mediterranean fshers. amino acid - amino acids are the fundamental building blocks of proteins. Examples include glycine, glutamic acid, alanine, proline, and arginine. Nature makes use of 20 different, specifc amino acids to construct proteins, which are chains of amino acids bound together with peptide bonds. Short chains are called polypeptides and long ones proteins. In food, amino acids are often found bound together in proteins and also as free amino acids that can have an effect on taste. An example is glutamic acid, which is the basis of umami. More than half of the free amino acids in cephalopods are of the type that are associated with the taste of seafood (arginine, glutamic acid, alanine, and glycine). ammonium chloride - sal ammonium or salmiac (NH4Cl) found throughout the mantle of the giant squid Architeuthis dux, as well as in other cephalopods that live at great depths. As it is lighter than seawater it helps to regulate buoyancy in the animals. 244 Glossary Anthropocene epoch - new geological epoch dating from the mid-1950s, the point at which humanity began to make irrevocable impressions on the Earth’s ecosystems. Architeuthis - from Greek archē (chief or principal) and teuthis (squid); genus name for the giant squid Architeuthis dux. argonaut - (paper nautilus) cephalopod belonging to the species Argonauta, enclosed in a shell. arthropods - phylum of invertebrates with exoskeletons, for example, insects and crustaceans. ATP - see adenosine triphosphate. axon - long, thin projection of a nerve cell that sends signals to other nerve cells. belemnites - (Belemnoidea) group of cephalopods that were abundant during the Cretaceous Period (from about 145 million to 66 million years ago) and that became extinct at the same time as dinosaurs; fossilized remains are known popularly as thunderstones. bilateral organism - organism that has two virtually iden- tical symmetrical sides, for example, cephalopods and humans. biogenetic amines - substances that can be formed by an organism’s own enzymes and by microbial activity; potentially toxic when present in large quantities. bioluminescence - active light emitted by some organ- isms; produced when certain chemical reactions take place in bacteria that live in symbiosis with the host organism. blue-ringed octopuses - Hapalochlaena, genus of four different species of highly venomous octopuses found in the Indo-Pacifc region. bromelain - enzyme derived from fresh pineapples that can break down proteins such as collagen and gelatine, used as a meat tenderizer. calamar - also calamari, calamares, common names for various types of squid. Cambrian Explosion - event about 542 million years ago and lasting for about 50 million years. During this period there was an amazing outburst of new life forms, among them all the major phyla of present-day animals, includ- ing the molluscs (Mollusca). Cephalopods emerged toward the end of this time. 245 Glossary Cephalopoda - from the Greek kephalē (head) and pous (foot); class within the invertebrate phylum (Mollusca) made up of about 800 still living species, divided into two sub-classes: true cephalopods (Coleoida) and nautiluses (Nautiloida). chemoreceptor - receptor that can bind and identify a particular chemical substance. chitin - polysaccharide that is a component of the cell walls of some fungi and the exoskeleton of insects and crustaceans. Cephalopod beaks and the gladius of squid are made of chitin. chromatophores - small complex organs made up of pigment-containing cells that can refect light. cirri - appendages around the mouth of Nautilida (nauti- luses). class - biological classifcation between phylum and order, for example, Cephalopoda are a class under Mollusca. Cnidaria - phylum of invertebrates, characterized by spe- cial cells used for capturing prey and bodies made up of a non-living jelly-like substance; divided into polyps, such as sea anemones, that are sessile and medusae, such as jellyfsh, that swim. Coleoidea - sub-class that groups together all the cephalopods that have no shells; divided into the Belemnoidea, now extinct, and the Neocoleoidea, that includes all present-day cephalopods. Their common characteristics are a number of arms surrounding the mouth, very highly developed eyes, three hearts, and the ability to eject ink. collagen - protein network that forms connective tissues and thereby gives structure to all animal tissues, found mostly