The family 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 common name, glass squid, derives from the transparent nature of most species. Cranchiid squid spend much of their lives in partially sunlit shallow waters, where their transparency provides camouflage. They are characterised by a swollen body and short arms, which bear two rows of suckers or hooks. The third arm 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 solution is used to aid buoyancy. 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. 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 colossal squid. 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 Cranchiinae is a subfamily containing four genus, genera of glass squids. Species *Genus ''Cranchia'' William Elford Leach, Leach, 1817 **''Cranchia scabra'' William ELford Leach, Leach, 1817 *Genus ''Leachia'' Charles Alexandre Lesueur, Lesueur ...

**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 ''Helicocranchia'' is a genus of small glass squids from the family Cranchiidae, known as piglet squid. They are characterized by possessing a very large funnel and in having a pair of small paddle-like fins which are attached to a part of the g ...

'' **Genus ''

Liguriella ''Liguriella'' is a genus of glass squids, the genus is probably monotypic, the only species being ''Liguriella podophthalma''. The other named species '' Liguriella pardus'', which was described by S. Stillman Berry in 1916, is cited as a ''ta ...

'' **Genus ''

Megalocranchia ''Megalocranchia'' is a genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of bio ...

'' **Genus '' Mesonychoteuthis'' **Genus '' Sandalops'' **Genus '' Taonius'' **Genus ''

Teuthowenia ''Teuthowenia'' is a genus of glass squid in the subfamily Taoniinae. Members of this genus are characterized by their deep-sea habitat, clear bodies, and ability to engorge themselves with water to become larger when threatened. Each known spe ...

'' 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