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.
A cephalopod is any member of the molluscan class Cephalopoda such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology.
The Mesozoa are minuscule, worm-like parasites of marine invertebrates. Generally, these tiny, elusive creatures consist of a somatoderm of ciliated cells surrounding one or more reproductive cells.
Sepiadariidae is a family of coleoid cephalopods in the order Sepiida.
Idiosepius is a genus of squids in the family Idiosepiidae. They are small, reaching mantle lengths of no more than about 21 mm (0.8 in); members of this genus represent no interest to commercial fisheries. They occur in tropical and temperate waters throughout the Indo-Pacific, primarily in association with seagrass and mangrove roots.
Sepiolidae is a family of bobtail squid encompassing 15 genera in three or four subfamilies. A gladius is absent in subfamily Heteroteuthidinae, and in subfamily Sepiolinae it is reduced, or absent like in genus Euprymna. A third subfamily is Rossiinae, and the genus Choneteuthis is considered to be Incertae sedis. Though 72 species have been recognized in Sepiolidae, the validity of a few of them has been questioned.
Coleoidea or Dibranchiata is one of the two subclasses of cephalopods containing all the various taxa popularly thought of as "soft-bodied" or "shell-less". Unlike its extant sister group Nautiloidea, whose members have a rigid outer shell for protection, the coleoids have at most an internal shell called cuttlebone or gladius that is used for buoyancy or as muscle anchorage. Some species, notably incirrate octopuses, have lost their internal shell altogether, while in some it has been replaced by a chitinous support structure.
Dicyemida, also known as Rhombozoa, is a phylum of tiny parasites that live in the renal appendages of cephalopods.
Decapodiformes is a superorder of Cephalopoda comprising all cephalopod species with ten limbs, specifically eight short arms and two long tentacles. It is hypothesized that the ancestral coleoid had five identical pairs of limbs, and that one branch of descendants evolved a modified arm pair IV to become the Decapodiformes, while another branch of descendants evolved and then eventually lost its arm pair II, becoming the Octopodiformes.
The pharaoh cuttlefish is a large cuttlefish species, growing to 42 cm in mantle length and 5 kg in weight.
Sepioloidea is a genus of cephalopod comprising three species.
Cephalopod ink is a dark-coloured or luminous ink released into water by most species of cephalopod, usually as an escape mechanism. All cephalopods, with the exception of the Nautilidae and the Cirrina, are able to release ink to confuse predators.
Cuttlefish, or cuttles, are marine molluscs of the suborder Sepiina. They belong to the class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone, which is used for control of buoyancy.
Sepioloidea pacifica, also known as the Pacific bobtail squid, is a species of cuttlefish native to the southern Pacific Ocean; it occurs off New Zealand in the west and in the Nazca and Sala y Gomez submarine ridges in the east.
Dicyema shimantoense is a parasitic worm of the phylum Dicyemida. It is a vermiform mesozoan parasite that infects the renal appendages of the cephalopod Octopus sasakii. The name is derived from the Shimanto River, which is the longest river in Shikoku, and flows into Tosa Bay. A study from 2000-06 used 59 specimens obtained from fishermen at Tosa Bay and Kii Strait in Japan. O. sasakii is a cephalopod found mainly in the shallow-water of Southern Japan. Research found that only those of certain sizes and geographical locations can be infected by D.shimantoense.
The Dicyemidae is a family of tiny parasites that live in the renal appendages of cephalopods. It contains the following genera and species:
Amanda "Mandy" Louise Reid is an Australian taxonomist and malacologist. She held the position of collection manager of malacology at the Australian Museum from 2010 to 2023. She is a published researcher and author. Her research has resulted in the description of many species of velvet worms and cephalopods.
Sepioloidea magna is a species of cuttlefish, more precisely a bottletail squid, of the family Sepiadariidae, indigenous to the waters off northern Australia. It was described by Amanda Reid in 2009 from specimens which were found in the Museum and Art Gallery of the Northern Territory in Darwin, Northern Territory. It differs from its congeners in the genus Sepioloidea in its larger size, its modified hectocotylus, the number of tentacular club suckers and the absence of an obvious colour pattern It has been recorded from relatively deep water, between 225m and 300m, in the Arafura Sea north of Darwin, Australia, and south of the eastern Indonesian islands of Tanimbar. Other specimens identified as Sepioloidea and occurring at similar depths, from the North West Shelf, Scott Reef and the Timor Sea probably also represent this species.
Sepiadarium austrinum, the southern bottletail squid, is a species of cuttlefish in the genus Sepiadarium. It was first described by S. Stillman Berry in 1921 based on a specimen found in St. Vincent Bay in South Australia.
