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Cirrina
Cirrina or Cirrata is a suborder and one of the two main divisions of octopuses. Cirrate octopuses have a small, internal shell and two fins on their head, while their sister suborder Incirrina has neither. The fins of cirrate octopods are associated with a unique cartilage-like shell in a shell sac. In cross-section, the fins have distinct proximal and distal regions, both of which are covered by a thin surface sheath of muscle. The suborder is named for small, cilia-like strands (cirri) on the arms of the octopus, a pair for each sucker. These are thought to play some role in feeding, perhaps by creating currents of water that help bring food closer to the beak. Cirrate octopuses are noteworthy for lacking ink sacs. Phylogeny A molecular phylogeny based on mitochondrial and nuclear DNA marker sequences by Sanchez et al., 2018, shows that the Cirrina is paraphyletic, i.e. it is not a single clade. Instead, a clade containing Opisthoteuthidae and Cirroctopodidae is siste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopus
An octopus ( : octopuses or octopodes, see below for variants) 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. Octopuses inhabit various regions of the ocean, including coral reefs, pelagic waters, and the seabed; some live in the intertidal zone and others at abyssal depths. Most species grow quickly, mature earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incirrina
Incirrata (or Incirrina) is a suborder of the order Octopoda. The suborder contains the classic " benthic octopuses," as well as many pelagic octopus families, including the paper nautiluses. The incirrate octopuses are distinguished from the cirrate octopuses by the absence in the former of the "cirri" filaments (found with the suckers) for which the cirrates are named, as well as by the lack of paired swimming fins on the head, and lack of a small internal shell (the "shell" of '' Argonauta'' species is not a true shell, but a thin calcite egg case). Classification *CLASS CEPHALOPODA **Subclass Nautiloidea: nautilus **Subclass †Ammonoidea: ammonites **Subclass Coleoidea ***Superorder Decapodiformes: squid, cuttlefish ***Superorder Octopodiformes ****Family † Trachyteuthididae (''incertae sedis'') ****Order Vampyromorphida: vampire squid ****Order Octopoda *****Genus †'' Keuppia'' (''incertae sedis'') *****Genus †'' Palaeoctopus'' (''incertae sedis'') *****Genu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopoda
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") 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 (muscular hydrostats) 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. Cephalopods became dominant during the Ordovician period, represented by primitive nautiloids. The class now contains two, only distantly related, extant subclasses: Coleoidea, which includes octopuses, squid, and cuttlefish; and Nautiloidea, represented by ''Nautilus'' and '' Allonautilus''. In the Coleoidea, the molluscan shell has been internalized or is absent, whereas in the Nautiloidea, the external shell remains. About 800 living species of cephalopods have been identified ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrothauma Murrayi
''Cirrothauma murrayi,'' commonly called the "Blind cirrate octopus," is a nearly blind octopus whose eyes can sense light, but not form images. It has been found worldwide, usually beneath the ocean's surface. Like other cirrates, it has an internal shell, muscular fins for swimming, and a web connecting the arms. The species was first caught by an expedition led by Sir John Murray in 1910, and it was later named in honor of Murray. It was described by German marine biologist Carl Chun in 1911. The large buccal mass, esophagus, and stomach of the ''Cirrothauma Murrayi'' strongly suggest whole organisms, especially crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gr ..., are part of its diet. The enzymatic action of salivary excretions separates the crustacean's musculos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopodiformes
Octopodiformes is a superorder of the subclass Coleoidea, comprising the octopuses and the vampire squid. All living members of Octopodiformes have eight arms, either lacking the two tentacles of squid (as is the case in octopuses) or modifying the tentacles into thin filaments (as in vampire squid). Octopodiformes is often considered the crown group of octopuses and vampire squids, including all descendants of their common ancestor. Some authors use the term Vampyropoda for the same general category, though others use "Vampyropoda" to refer to the total group (all cephalopods closer to octopods than to true squid). Another term is Octobranchia, referring to cephalopods without prominent tentacles. ''Pohlsepia'', originally described as earliest octopod is considered as dubious for this group in later study. The oldest unambiguous vampyropod is ''Syllipsimopodi'', a squid-like cephalopod from the Mississippian-age Bear Gulch Lagerstätte of Montana. ''Syllipsimopodi'' has a combi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrate Shell
Cirrate octopuses possess a well-developed internal shell that supports their muscular swimming fins. This is in contrast to the more familiar, finless, incirrate octopuses, in which the shell remnant is either present as a pair of stylets or absent altogether. The cirrate shell is quite unlike that of any other living cephalopod group and has its own dedicated set of descriptive terms. It is usually roughly arch- or saddle-shaped and is rather soft, being similar in consistency to cartilage. Each of the eight extant cirrate genera is characterised by a distinct shell morphology: *Cirroteuthidae **''Cirroteuthis'' — saddle-shaped, with large wings **''Cirrothauma'' — butterfly-shaped *Opisthoteuthidae **''Cirroctopus'' — V-shaped, lateral wings tapering to fine points **'' Cryptoteuthis'' — U-shaped, each lateral wing ending in broad lobe with pointed projection **'' Grimpoteuthis'' — U-shaped, lateral wings ending bluntly **'' Luteuthis'' — W-shaped **''Opisthote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod Fin
Cephalopod fins, sometimes known as wings,Young, R.E., M. Vecchione & K.M. Mangold (1999)Cephalopoda Glossary Tree of Life Web Project. are paired flap-like locomotory appendages. They are found in ten-limbed cephalopods (including squid, bobtail squid, cuttlefish, and ''Spirula'') as well as in the eight-limbed cirrate octopuses and vampire squid. Many extinct cephalopod groups also possessed fins. Nautiluses and the more familiar incirrate octopuses lack swimming fins. An extreme development of the cephalopod fin is seen in the bigfin squid of the family Magnapinnidae. Fins project from the mantle and are often positioned dorsally. In most cephalopods, the fins are restricted to the posterior end of the mantle, but in cuttlefish and some squid they span the mantle's entire length. Fin attachment varies greatly among cephalopods, though in all cases it involves specialised fin cartilage (which reaches its greatest development in Octopodiformes). A fin may be attached to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirroteuthidae
Cirroteuthidae is a family of cirrate octopuses comprising three species in two genera. Species *Genus ''Cirroteuthis'' **'' Cirroteuthis muelleri'' *Genus '' Cirrothauma'' **'' Cirrothauma magna'' **''Cirrothauma murrayi ''Cirrothauma murrayi,'' commonly called the "Blind cirrate octopus," is a nearly blind octopus whose eyes can sense light, but not form images. It has been found worldwide, usually beneath the ocean's surface. Like other cirrates, it has an int ...'', blind cirrate External linksTree of Life website gives information about the classification of cephalopod groups Octopuses [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by ' (of uncertain family), ' (of uncertain suborder), ' (of uncertain order) and similar terms. Examples *The fossil plant '' Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil '' Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Bocage's longbill, ''Motacilla boc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vampyromorphida
Vampyromorphida is an order of cephalopods comprising one known extant species ('' Vampyroteuthis infernalis'') and many extinct taxa. Physically, they somewhat resemble octopuses (their closest relatives), but the eight arms are united by a web of skin, and two smaller cilia are also present. Properly speaking, the vampire squid does not possess cilia, but cirri (cilia-like projections). Classification *Order Vampyromorphida **Suborder † Kelaenina ***Family † Muensterellidae **Suborder † Prototeuthina ***Family † Loligosepiidae ***Family † Geopeltididae ***Family † Lioteuthididae ***Family † Mastigophoridae **Suborder † Mesoteuthina ***Family † Palaeololiginidae ****Subfamily † Teudopseinae ****Subfamily † Palaeololigininae **Suborder Vampyromorphina ***Family Vampyroteuthidae The following taxa were long considered to belong to Vampyromorphida, but this placement may be incorrect:Fischer, Jean-Claude & Riou, Bernard (2002): ''Vampyronassa rhodanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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