|
Paralarva
Coleoidea or Dibranchiata is one of the two subclasses of cephalopod molluscs containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e. octopus, squid and cuttlefish). 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 Some species, notably incirrate octopuses, have lost their internal shell altogether, while in some it has been replaced by a chitinous support structure. The major divisions of Coleoidea are based upon the number of arms or tentacles and their structure. The extinct and most primitive form, the Belemnoidea, presumably had ten equally-sized arms in five pairs numbered dorsal to ventral as I, II, III, IV and V. More modern species either modified or lost a pair of arms. The superorder Decapodiformes has arm pair IV modified into long tentacles with suckers gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod
A cephalopod is any member of the molluscan Taxonomic rank, class Cephalopoda (Greek language, Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral symmetry, bilateral body symmetry, a prominent head, and a set of cephalopod arm, arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishers sometimes call cephalopods "inkfish", referring to their common ability to squirt Cephalopod ink, 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 taxon, extant subclasses: Coleoidea, which includes octopuses, squid, and cuttlefish; and Nautiloidea, represented by ''Nautilus (genus), Nautilus'' and ''Allonautilus''. In the Coleoidea, the molluscan shell has been internalized or is absent, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squid
A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (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, Symmetry (biology)#Bilateral symmetry, bilateral symmetry, and a mantle (mollusc), mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius (cephalopod), gladius or pen, made of chitin. Squid diverged from other cephalopods during the Jurassic and occupy a similar Ecological niche, role to teleost fish as open-water predators of similar size and behaviour. They play an important role in the open-water food web. The two long tentacles are used to grab prey and the eight arms to hold and control it. The beak then cuts the food into suitable size chunks for swal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gladius (cephalopod)
The gladius (: ''gladii''), or pen, is a hard internal bodypart found in many cephalopods of the superorder Decapodiformes (particularly squids) and in a single extant taxon, extant member of the Octopodiformes, the vampire squid (''Vampyroteuthis infernalis''). It is so named for its superficial resemblance to the Roman Empire, Roman Gladius, short sword of the same name, and is a Vestigiality, vestige of the ancestral mollusc shell, which was external. The gladius is located Dorsal (anatomy), dorsally within the mantle (mollusc), mantle and usually extends for its entire length. Composed primarily of chitin, it lies within the shell sac, which is responsible for its secretion. Some species, like the bigfin reef squid, still has a gladius with some degree of mineralization. Gladii are known from a number of extinct cephalopod groups, including Teudopseina, teudopseids (''e.g.'' ''Actinosepia'', ''Glyphiteuthis'', ''Muensterella'', ''Palaeololigo'', ''Teudopsinia'', ''Teudopsis'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cuttlefish
Cuttlefish, or cuttles, are Marine (ocean), marine Mollusca, molluscs of the order (biology), suborder Sepiina. They belong to the class (biology), class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique internal mollusc shell, shell, the cuttlebone, which is used for control of buoyancy. Cuttlefish have large, W-shaped pupils, eight Cephalopod arm, arms, and two tentacles furnished with :wikt:denticulate, denticulated suckers, with which they secure their prey. They generally range in size from , with Cephalopod size, the largest species, the giant cuttlefish (''Sepia apama''), reaching in mantle (mollusc), mantle length and over in mass. Cuttlefish eat small molluscs, crabs, shrimp, fish, octopuses, worms, and other cuttlefish. Their predators include dolphins, larger fish (including sharks), seals, seabirds, and other cuttlefish. The typical life expectancy of a cuttlefish is about 1–2 years. Studies are said to indicate cuttlefis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsum (biology)
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and axes. The meaning of terms that are used can change depending on whether a vertebrate is a biped or a quadruped, due to the difference in the neuraxis, or if an invertebrate is a non-bilaterian. A non-bilaterian has no anterior or posterior surface for example but can still have a descriptor used such as proximal or distal in relation to a body part that is nearest to, or furthest from its middle. International organisations have determined vocabularies that are often used as standards for subdisciplines of anatomy. For example, '' Terminolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superorder
Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. For some groups of organisms, their orders may follow consiste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decapodiformes
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. Taxonomy The following orders are recognised in the superorder Decapodiformes: * Bathyteuthida * †Belemnitida * † Diplobelida * Idiosepida – pygmy squid * Myopsida – coastal squid * Oegopsida – neritic squid * Sepiida 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 ... – cuttlefish, bobtail and bottletail squid * Spirulida – ram's ... [...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 Octobrachia, referring to cephalopods without prominent tentacles. It is considered one of the two extant groups of the Neocoleoidea. '' Pohlsepia'', originally described as earliest octopod is considered as dubious for this group in later study. ''Syllipsimopodi'', a squid-like cephalopod from the Mississippian-age Bear Gulch Lagerstätte of Monta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distal
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and axes. The meaning of terms that are used can change depending on whether a vertebrate is a biped or a quadruped, due to the difference in the neuraxis, or if an invertebrate is a non-bilaterian. A non-bilaterian has no anterior or posterior surface for example but can still have a descriptor used such as proximal or distal in relation to a body part that is nearest to, or furthest from its middle. International organisations have determined vocabularies that are often used as standards for subdisciplines of anatomy. For example, '' Terminologia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalopod Arm
All cephalopods possess flexible limbs extending from their heads and surrounding their beaks. These appendages, which function as muscular hydrostats, have been variously termed arms, legs or tentacles. Description In the scientific literature, a cephalopod ''arm'' is often treated as distinct from a ''tentacle'', though the terms are sometimes used interchangeably, often with the latter acting as an umbrella term for cephalopod limbs. Generally, arms have suckers along most of their length, as opposed to tentacles, which have suckers only near their ends.Young, R.E., M. Vecchione & K.M. Mangold 1999Cephalopoda Glossary Tree of Life web project. Barring a few exceptions, octopuses have eight arms and no tentacles, while squid and cuttlefish have eight arms (or two "legs" and six "arms") and two tentacles.Norman, M. 2000. ''Cephalopods: A World Guide''. ConchBooks, Hackenheim. p. 15. "There is some confusion around the terms ''arms'' versus ''tentacles''. The numerous l ... [...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 are often called vampire squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...s. Unlike octopuses, their 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). Unlike most cephalopods, which are high-energy hunters, the vampire squid has an extremely low metabolic rate. This adaptation means it requires less oxygen and its food lasts longer, helping it conserve energy and thrive in these harsh deep-sea conditions. Studies show its oxygen consumption is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
