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 center 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 superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria. 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 more than 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 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 draughtsboard shark is a species of catshark, and part of the family Scyliorhinidae, so named for its "checkerboard" colour pattern of dark blotches. It is endemic to New Zealand, where it is also known as the carpet shark. This shark typically reaches 1 m (3.3 ft) in length and has a thick body with a broad, flattened head and a capacious mouth. Its two dorsal fins are placed far back on the body, with the first much larger than the second.
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. They can also be known as Pinnoctopus cordiformis, 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, 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.
Holothuria fuscocinerea, the ashy pink sea cucumber, is a species of sea cucumber in the family Holothuriidae. It is placed in the subgenus Stauropora, making its full name Holothuria (Stauropora) fuscocinerea. It is native to shallow water in the tropical and sub-tropical Indo-Pacific.
Grimpoteuthis boylei is a species of octopus known from only ten individuals.
Ctenogobiops tangaroai, the silver-spotted shrimp-goby, is a species of bony fish of the family Gobiidae, native to the reefs which is widespread in the Indo-West Pacific, from the Red Sea and Western Indian Ocean through northern Australia and Taiwan, southern Japan and Fiji. It occurs in fine-grained sand patches at depths of from 4 to 40 metres where it is commensal with alpheid shrimps, with a fish and shrimp sharing a burrow. This species can reach a length of 6 centimetres (2.4 in) TL. It can also be found in the aquarium trade. It is pale in colour marked with four rows of brown spots or dashes along its flanks, three diagonal rows of short, dark stripes on the posterior of its head with larger dark spots on the lower flanks which are frequently surrounded by smaller blue spots and there is a small white stripe above the pectoral fin base with a longer white streak on the pectoral fin. It is the type species of the genus Ctenogobiops.
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.
