The second is the release of one or more com- Intelligence Quick Facts pact, mucus-bound clouds close to the size of , and in particular , are  Octopuses, , , and nautiluses are all cephalopods. the cephalopod intended to confuse the preda- generally considered to be the most intelligent Cephalopods tor as to which is the real ; this behavior of the invertebrates, but even so assessment of  Cephalopods are mollusks and are related to snails, may also be accompanied by the cephalopod their intelligence remains controversial. What is slugs, clams, mussels, and oysters. changing color or “blanching.” clear is that cephalopods have the most complex  Cephalopods have lived in the Earth’s oceanic Phylum: Cephalopods are fast-moving hunters that de- brains of any invertebrate, enclosed in a carti- basins for more than 500 million years, and were laginous brain capsule and surrounding the dominant predators millions of years before fish pend on vision to locate prey, detect predators, appeared. and communicate with one another. The cepha- throat, it contains about 40 lobes and “up to” The Intelligent Invertebrates lopod eye is probably the most sophisticated of 300 million neurons (information processing  Nautiluses are the only cephalopod with external nerve cells). However, cephalopod nervous sys- shells; squids and cuttlefish have internal shells; all the inverte- and octopuses have none at all. brates and is as tems are not strongly centralized in the way that complex as the vertebrates’ are; for instance octopuses’ nervous  Octopuses, squids, and cuttlefish have three vertebrate systems have about 500 million neurons but hearts, and their blood is blue when exposed to air. eye; as such it two-thirds are located in the nerve cords of the  The nervous system of cephalopods is the most is an often arms and the arms exhibit significant autonomy complex of the invertebrates and their brain is lo- cited example even when disconnected from the brain. cated in a capsule around their throats.  Octopuses have a toxin to neutralize their prey but of convergent Scientists studying octopuses have found indica- evolution. only two types can kill humans with their toxin tions of intelligence in their ability to recognize (some blue ring species and O. mototi). Like vertebrates, coleoid eyes contain an iris, shapes and patterns, to learn simple mazes, and to use landmarks for navigation while hunting. pupil, and lens but not necessarily a cornea. REMEMBER Among coleoids have round pupils, One study even appeared to document that octo- while those of are rectangular and the puses engage in play behavior when given an The Institute for Marine Mammal Studies cuttlefish’s is W-shaped. The eyes of the nauti- object to manipulate in an otherwise non- (IMMS) is a non-profit organization established loids are less sophisticated than other cephalo- stimulating environment. In the wild octopuses in 1984 for the purpose of public education, pods; lacking a lens they have a small opening have been observed to engage in planning and conservation, and research of marine mam- that acts like a “pin-hole” camera. tool use in the collection, transport, and assem- mals and sea turtles in the wild and under hu- bly of items like coconut and clam shells to cre- man care. Located in Gulfport, MS, IMMS has Somewhat paradoxically, the feature that ate shelters. been an active participant in the National makes the coleoids excellent visual communi- Stranding Network since its inception. IMMS is cators also makes them unchallenged masters Much work still needs to be accomplished to the premiere organization in the Mississippi- of camouflage. They have the ability to rapidly assess the degree and nature of cephalopod in- Louisiana-Alabama sub-region of the Gulf and precisely vary the color, patterning and telligence, but it is apparent that these ancient Coast with the capability and experience to texture of their skin. This is possible through and unique will continue to fascinate care for sick and injured marine mammals and fine-motor control of projections on the skin scientists and lay-persons alike for the foreseea- sea turtles. Additionally, IMMS promotes public called papillae, and pigment-containing and ble future. awareness of marine conservation issues light-reflecting cells (chromatophores) located through its involvement in the community. References at, or directly under, the skin’s surface. This Dr J.B. Wood’s Cephalopod Page: www.thecephalopodpage.org control is so precise that some squid have been The Octopus News Magazine Online: www.tonmo.com Laboratory of Robert Hanlon: www.mbl.edu/mrc/hanlon/ Institute for Marine Mammal Studies observed “double signaling,” using half their Unless otherwise noted all images in this publication were obtained P.O. Box 207, Gulfport, MS 39502 body to communicate with an animal on that from: http://commons.wikimedia.org Phone 228-896-9182 Fax: 228-896-9183 side while sending a completely different sig- Email: [email protected] This brochure is funded with qualiied outer continental shelf oil nal to a receiver on the other side. and gas revenues by the Coastal Impact Assistance Program, Website: www.imms.org United States Fish and Wildlife Service, U.S. Department of the www.imms.org Interior through a grant award to the Mississippi Department of Prepared by Mike Mashburn, 2012 Marine Resources. Scientific Classification The fossil record contains about 17,000 species of The arms of coleoids are generally equipped Many mollusks cephalopods. Although their species’ diversity is with suction cups along their entire length. The have an external Kingdom: Animalia shell which shields greatly reduced in the modern era, cephalopods tentacles of squid and cuttlefish normally have are currently found in all of the Earth’s oceanic suction cups only at the distal end, and in some their mantle, but Phylum: Mollusca among cephalo- basins from the tropics to the polar seas and occu- squid these are accompanied by hooks. Nauti- py all depths from the abyssal plain to the wave- loids have around 90 small appendages, re- pods only the nau- Class: Cephalopoda tiloids possess such a shell. In cole- swept intertidal zone. ferred to as tentacles, which do not possess suckers but are sticky and partially retractable. oids the shell is internal, often Subclasses: greatly reduced and in some cases Nautiloidea Anatomy entirely absent. Notable examples of internal shells include the “ram’s As members of the phylum, Mollusca, the cepha- lopods are related to clams, mussels, slugs, snails horn shell” of Spirula spirula, the squid’s and even worm-like, deep-sea Aplacophora. They “pen,” and the cuttlefish’s cuttlebone, com- share common molluscan anatomical features, monly sold as a source of calcium for caged although many of these are significantly modified birds and reptiles. and refined in cephalopods. Cephalopods are the only mollusks to pos- sess a closed circulatory system. To carry A feature common to all mollusks is the mantle, oxygen in their blood cephalopods use cop- the dorsal body wall which covers the visceral per-based hemocyanin, which makes their organs and often extends in the form of flaps. In blood blue when exposed to air. Coleoids The Basics cephalopods the mantle is quite muscular and have paired branchial hearts that pump blood serves as an organ of respiration and locomotion. through their gills and a single systemic heart Cephalopods are exclusively marine animals Muscular contractions of the mantle cavity bring that transports blood to the other organs of represented by two extant subclasses, Nautiloi- oxygenated water to the gills which can then be the body. Each branchial heart is directly dea and Coleoidea, and one extinct subclass, expelled with significant force through the funnel, connected to a pericardial gland. The action Ammonoidea. Extant subclasses contain about giving the animals a sort of “jet propulsion.” The of the branchial hearts is necessary for the 800 species; Coleoidea includes the many spe- sudden burst of speed offered by “jetting” is use- production of primary urine in these glands cies of octopus, squid, and cuttlefish; and Nau- ful in capturing prey or avoiding predators but is via pressure filtration. tiloidea includes seven species of shelled Nau- very energy intensive. So, most cephalopods rely tilus and Allonautilus. primarily on their arms or fins for locomotion. Cephalopods use their appendages to capture All coleoids, except for species of the subor- prey and maneuver it to their centrally-located der Cirrina, are able to release clouds of ink Cephalopods are an an- mouth. All extant cephalopods have mouths to escape pursuit. The ink, primarily com- cient class which appeared equipped with a two-part beak, composed pri- posed of melanin, is produced in a muscular in the Earth’s ocean mil- marily of chitin, which they use to take bites of sac which developed from the hind-gut and lions of years before the their prey as they hold it with their arms. Be- opens into the anus. Due to the ink sac’s bony fishes. The earliest proximity to the base of the funnel, ink can cause they are virtually indigestible, beaks are cephalopods were primi- be dispersed by ejected water as the cephalo- The name cephalopod means often the only identifiable cephalopod remains tive shelled pod uses their “jet propulsion.” “head foot” and in cephalopods found in the stomachs of predatory species which evolved in the mid- such as sperm whales. the common molluscan “foot” has Two distinct uses of ink have been observed. to late-Cambrian period. Experiencing significant evolved into a number of appendages attached to The first is a simple release of a large, diffuse the head and surrounding the mouth. Octopuses diversification during the cloud of ink that serves as a “smokescreen” Ordovician period, cepha- have four pairs of arms, while squid and cuttlefish to obscure the predator’s view of the cepha- typically have five pairs, with one pair, called ten- lopods became dominant in the Paleozoic and Colossal Squid Beak lopod while it jets rapidly away. Mesozoic eras. tacles, being elongated. Mesonychoteuthis hamiltoni