An octopus is a soft-bodied, eight-limbed mollusc of the order Octopoda. The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the centre point of the eight limbs. The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. The siphon is used both for respiration and for locomotion, by expelling a jet of water. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates.
A squid is a mollusc with an elongated soft body, large eyes, eight arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin.
The California two-spot octopus, often simply called a "bimac", is an octopus species native to many parts of the Pacific Ocean including the coast of California. One can identify the species by the circular blue eyespots on each side of its head. Bimacs usually live to be about two years old. They are closely related to Verrill's two-spot octopus. In 2015, the genome was sequenced.
Octopus is the largest genus of octopuses, comprising about 100 species. These species are widespread throughout the world's oceans. Many species formerly placed in the genus Octopus are now assigned to other genera within the family. The octopus has 8 arms, averaging 20 cm (8 in) long for an adult.
The bigeye sand tiger is an extremely rare species of mackerel shark in the family Odontaspididae, with a possible worldwide distribution. A large, bulky species reaching at least 3.6 m (12 ft) in length, the bigeye sand tiger has a long bulbous snout, large orange eyes without nictitating membranes, and a capacious mouth with the narrow teeth prominently exposed. It can be distinguished from the similar smalltooth sand tiger by its teeth, which have only one lateral cusplet on each side, and by its uniformly dark brown color.
The sand devil or Atlantic angel shark is a species of angelshark, family Squatinidae, native to the northwestern Atlantic Ocean. It occurs off the eastern United States, in the northern Gulf of Mexico, and possibly in parts of the Caribbean Sea. This bottom-dwelling shark is found in shallow inshore waters in summer and fall, and deep offshore waters in winter and spring. The sand devil's flattened body and enlarged pectoral and pelvic fins give it a ray-like appearance. There is a band of enlarged thorns running along the middle of its back. It is gray or brown in color, with scattered small dark spots. This species reaches 1.2–1.5 m (3.9–4.9 ft) in length.
Metasepia pfefferi, also known as the flamboyant cuttlefish, is a species of cuttlefish occurring in tropical Indo-Pacific waters off northern Australia, southern New Guinea, as well as numerous islands of the Philippines, Indonesia and Malaysia.
Sepia latimanus, also known as the broadclub cuttlefish, is widely distributed from the Andaman Sea, east to Fiji, and south to northern Australia. It is the most common cuttlefish species on coral reefs, living at a depth of up to 30 m.
Velodona togata is a species of octopus in the monotypic genus Velodona. First described by Carl Chun in 1915, with a second subspecies discovered by Guy Coburn Robson in 1924, it was named for the distinctive membranes on its arms.
Callistoctopus macropus, also known as the Atlantic white-spotted octopus, white-spotted octopus, grass octopus or grass scuttle, is a species of octopus found in shallow areas of the Mediterranean Sea, the warmer parts of the eastern and western Atlantic Ocean, the Caribbean Sea, and the Indo-Pacific region. This octopus feeds on small organisms which lurk among the branches of corals.
Macroctopus maorum is known more commonly as the Maori octopus or the New Zealand octopus. It is found in the waters around New Zealand and southern Australia. M. maorum is one of the largest and most aggressive octopus species living in the New Zealand and Australian waters. They feed mainly on crustaceans and fish. Although they have a short life span, the females lay thousands of eggs and are very protective of them.
Callistoctopus ornatus is a tropical species of octopus native to the Indo-Pacific region. Other common names include white-striped octopus and night octopus, in reference to its nocturnal habits. It was previously known as Polypus ornatus. C. ornatus is edible and was recorded in a Hawaiian market in 1914 by S. S. Berry.
Eledone palari, commonly known as the spongetip octopus, is a species of benthic octopus from the coastal waters of the eastern Indian Ocean and the south-western Pacific. The species was formally described in 1992 and is the first species of the genus Eledone to be discovered which is not distributed in the Atlantic Ocean.
Callistoctopus is a genus of nocturnal, orange octopuses in the family Octopodidae. They are readily identifiable by their reddish coloring, the white papillae that line their bodies, and their long arms. Though sympatric with diurnal Octopus species, they avoid competition by hunting at night. In acknowledgement of this preference, many species of Callistoctopus are referred to as night octopuses. Well-known species include C. macropus and the type species C. ornatus, both of which are harvested for human consumption as seafood.
Grimpoteuthis boylei is a species of octopus known from only ten individuals.
Opisthoteuthis calypso or calypso flapjack octopus is a species of genus Opisthoteuthis, which are known as the cirrate octopuses. Octopuses in this genus are known as the flapjack octopuses and can be found in a variety of oceans across the world.
Octopus australis is a species of octopus. It gets the common name hammer octopus from a modified arm possessed by males and used in reproduction. It was first described by William Evans Hoyle in 1885, based on a specimen found in Port Jackson in New South Wales.
Octopus superciliosus is a species of octopus. It was first described in 1832 by Jean René Constant Quoy and Joseph Paul Gaimard based on a specimen found off Victoria during the 1826 to 1829 voyage of the Astrolabe.
Callistoctopus rapanui, or the rapanui octopus, is the only endemic octopus species in Rapa Nui. It was first described by Gilbert L. Voss in 1979 as Octopus rapanui.
Callistoctopus luteus, the starry night octopus, is a species of octopus within the family Octopodidae. The species is found distributed in the Western Pacific near areas such as the Gulf of Thailand, Taiwan, Vietnam, the Philippines, Indonesia, Japan, Timor, and Hawaii, with the type locality coming from the Pescadore Islands of Taiwan. Habitats include sandy seafloors, seaweed, and rubble areas to forage for prey at depths up to 82 meters. The species is reddish brown in color with several white spots, with a max length of 70 cm, and a mantle length of 12.5 cm.
