Chiroteuthis is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of chiroteuthid

Chiroteuthidae

Chiroteuthids are deep-sea squid of the family Chiroteuthidae. They are generally small to medium in size, rather soft and gelatinous, and slow moving. They are found in most temperate and tropical oceans, but are known primarily from the North Atlantic, North Pacific, and Indo-Pacific...

 squid

Squid

Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...

, comprising two subgenera

Subgenus

In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...

. The hectocotylus

Hectocotylus

A hectocotylus is one of the arms of the male of most kinds of cephalopods that is modified in various ways to effect the fertilization of the female's eggs. It is a specialized, extended muscular hydrostat used to store spermatophores, the male gametophore...

 is absent from all members of the genus; instead, a penis

Penis

The penis is a biological feature of male animals including both vertebrates and invertebrates...

 extending from the mantle

Mantle (mollusc)

The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...

 opening is utilised. The genus is characterised by enlarged, lidded photophore

Photophore

A photophore is a light-emitting organ which appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors...

s present at the end of the tentacular club. Arms

Cephalopod arm

A cephalopod arm is distinct from a tentacle, though the terms are often used interchangeably.Generally, cephalopod arms have suckers along most of their length, as opposed to tentacles, which have suckers only near their ends. Octopuses have eight arms and no tentacles, while squid and cuttlefish...

 IV are both the longest and thickest, their membranes

Biological membrane

A biological membrane or biomembrane is an enclosing or separatingmembrane that acts as a selective barrier, within or around a cell. It consists of a lipid bilayer with embedded proteins that may constitute close to 50% of membrane content...

 acting as sheath

Sheath

Sheath may refer to:* Scabbard, a sheath for holding a sword, knife, or other large blade, as well as guns, such as rifles.* The outer covering of a cable* Condom, a kind of contraception* Debye sheath, a layer of a plasma in physics...

s to the retractable tentacle

Tentacle

A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...

s.

Species

• • Chiroteuthis sp. B2
  • Subgenus Chiroteuthis
    • Chiroteuthis calyx
    • Chiroteuthis joubini
    • Chiroteuthis spoeli
    • Long-armed Squid, Chiroteuthis veranyi
      • Chiroteuthis veranyi lacertosa
      • Chiroteuthis veranyi veranyi
  • Subgenus Chirothauma
    • Chiroteuthis atlanticus *
    • Chiroteuthis imperator
      Chiroteuthis imperator
      Chiroteuthis imperator is a species of chiroteuthid squid. It lives of the coast of Sumatra. It grows to a mantle length of 30 cm....
      
      
    • Chiroteuthis mega
    • Chiroteuthis picteti
      • Chiroteuthis picteti picteti
      • Chiroteuthis picteti somaliensis

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

External links

• Tree of Life web project: Chiroteuthis