The

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Cranchiidae comprises the approximately 60 species of glass squid, also known as cockatoo squid, cranchiid, cranch squid, or bathyscaphoid squid. Cranchiid squid occur in surface and midwater depths of open oceans around the world. They range in

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

length from to over , in the case of the

colossal squid The colossal squid (''Mesonychoteuthis hamiltoni'') is part of the family Cranchiidae. It is sometimes called the Antarctic squid or giant cranch squid and is believed to be the largest squid species in terms of mass. It is the only recognize ...

. The common name, glass squid, derives from the

transparent Transparency, transparence or transparent most often refer to: * Transparency (optics), the physical property of allowing the transmission of light through a material They may also refer to: Literal uses * Transparency (photography), a still, ...

nature of most species. Cranchiid squid spend much of their lives in partially sunlit shallow waters, where their transparency provides

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the ...

. They are characterised by a swollen body and short arms, which bear two rows of

sucker Sucker may refer to: General use * Lollipop or sucker, a type of confection * Sucker (slang), a slang term for a very gullible person * Hard candy ** Cough drop ** Mint (candy) Biology * Sucker (botany), a term for a shoot that arises undergro ...

s or hooks. The third

arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between the ...

pair is often enlarged. Many species are

bioluminescent Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorganisms including ...

organisms and possess light organs on the undersides of their

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...

s, used to cancel their shadows. Eye morphology varies widely, ranging from large and circular to telescopic and stalked. A large, fluid-filled chamber containing

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...

solution is used to aid

buoyancy Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the p ...

. This buoyancy system is unique to the family and is the source of their common name "bathyscaphoid squid", after their resemblance to a

bathyscaphe A bathyscaphe ( or ) is a free-diving self-propelled deep-sea submersible, consisting of a crew cabin similar to a bathysphere, but suspended below a float rather than from a surface cable, as in the classic bathysphere design. The float is fi ...

. Often the only

organ Organ may refer to: Biology * Organ (biology), a part of an organism Musical instruments * Organ (music), a family of keyboard musical instruments characterized by sustained tone ** Electronic organ, an electronic keyboard instrument ** Hammond ...

that is visible through the transparent tissues is a cigar-shaped digestive

gland In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

, which is the

cephalopod 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 ...

equivalent of a

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

ian

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

. This is usually held in a vertical position to reduce its silhouette and a light organ is sometimes present on the lower tip to further minimise its appearance in the water. Mark Norman 2000. ''Cephalopods: A World Guide''. Hackenheim, ConchBooks, p. 156. Like most squid, the juveniles of cranchiid squid live in surface waters, descending to deeper waters as they mature. Some species live over 2 km below sea level. The body shape of many species changes drastically between growth stages, and many young examples could be confused for different species altogether. The largest squid in the family Cranchiidae is the

. Cranchiid squid represent no interest to commercial

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...

. The family is named for John Cranch.

Genera

The family contains two

subfamilies In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

(both established by

Georg Johann Pfeffer Georg Johann Pfeffer (1854–1931) was a German zoologist, primarily a malacologist, a scientist who studies mollusks. Pfeffer was born in Berlin. In 1887 he became curator of the , which was established in 1843 and destroyed during World War II. ...

) and about 15 genera: *Subfamily Cranchiinae **Genus '' Cranchia'' **Genus ''

Leachia ''Leachia'' is a genus containing eight species of glass squids. The genus was formerly divided into two subgenera: ''Leachia'' and ''Pyrgopsis'', but is no longer. Members of this genus live in tropical and sub-tropical waters worldwide. De ...

'' **Genus '' Liocranchia'' *Subfamily

Taoniinae Taoniinae is a subfamily containing ten genera of glass squids. Description Unlike Cranchiinae , the other subfamily within Cranchiidae , Taoniinae all lack cartilaginous strips which extend back from the funnel-mantle point of fusion. Their ...

**Genus '' Bathothauma'' **Genus '' Belonella'' **Genus '' Egea'' **Genus ''

Galiteuthis ''Galiteuthis'' is a genus of glass squids from the family Cranchiidae and the subfamily Taoniinae. Squids in the genus ''Galiteuthis'' are large squids with mantle lengths measuring up to 660mm, although it has been suggested that mantle leng ...

'' **Genus '' Helicocranchia'' **Genus '' Liguriella'' **Genus '' Megalocranchia'' **Genus '' Mesonychoteuthis'' **Genus '' Sandalops'' **Genus ''

Taonius ''Taonius'' is a small genus of glass squid. Although it comprises only three recognised species, it has been suggested there may be as many as five species In biology, a species is the basic unit of classification and a taxonomic rank o ...

'' **Genus '' Teuthowenia'' The genus listed above with an asterisk (*) is questionable and needs further study to determine if it is a valid genus or a synonym.

References

External links

{{Taxonbar, from=Q1492395 Squid