Oegopsina
Encyclopedia
Oegopsina is a suborder of the squid
order, Teuthida, in the Cephalopod
Class. Some taxonomists raise it to the level of an order, in which case it is known as Oegopsida.
The Oegopsina are deep sea pelagic squid comprising some 24 families
and 69 genera
. They have the following characters in common: the head is without tentacle pockets, eyes lack a corneal covering, arms and tentacle clubs may have hooks, the buccal supports are without suckers, and oviducts in females are paired.
Two families, the Bathyteuthidae and Chtenopterygidae, which have features characteristic of the Myopsina
while retaining others common to the Oegopsina, are sometimes placed in the Bathyteuthoidea
.
The Oegopsina differ from the coastal Myopsina, characterised by the genus Loligo
, which have corneal coverings over the eyes and tentacle pockets but lack hooks, have no suckers on the buccal supports and a single oviduct.
Oegopsid squid are the only decapods that lack a pocket for the tentacles. Otherwise they share different characters with different decapod groups. Like the Bathyteuthoidea and Myopsina, the Oegopsina have a brachial canal, which is absent in other forms. As with the Spirulidae and Idiosepiidae
, the Oegposina lack suckers on the buccal supports, and like the Bathyteuthoidea, Idiosepiidae, and Spirulidae they have no circular muscle on the suckers.
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...
order, Teuthida, in the Cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
Class. Some taxonomists raise it to the level of an order, in which case it is known as Oegopsida.
The Oegopsina are deep sea pelagic squid comprising some 24 families
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
and 69 genera
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...
. They have the following characters in common: the head is without tentacle pockets, eyes lack a corneal covering, arms and tentacle clubs may have hooks, the buccal supports are without suckers, and oviducts in females are paired.
Two families, the Bathyteuthidae and Chtenopterygidae, which have features characteristic of the Myopsina
Myopsina
Myopsina is a suborder of squid containing two families. Some systematists raise it to the level of an order, in which case it is known as Myopsida.-External links:*...
while retaining others common to the Oegopsina, are sometimes placed in the Bathyteuthoidea
Bathyteuthoidea
The Bathyteuthoidea are small, mesopelagic to bathypelagic squid that in some ways resemble myopsid squid, such as Loligo and in others the pelagic oegopsid squid...
.
The Oegopsina differ from the coastal Myopsina, characterised by the genus Loligo
Loligo
Loligo is a genus of squids and one of the most representative and widely distributed groups of myopsid squids.The genus was first described by Jean Baptiste Lamarck in 1798. However, the name had been used earlier than Lamarck and might even have been used by Pliny...
, which have corneal coverings over the eyes and tentacle pockets but lack hooks, have no suckers on the buccal supports and a single oviduct.
Oegopsid squid are the only decapods that lack a pocket for the tentacles. Otherwise they share different characters with different decapod groups. Like the Bathyteuthoidea and Myopsina, the Oegopsina have a brachial canal, which is absent in other forms. As with the Spirulidae and Idiosepiidae
Idiosepiidae
Idiosepius is a genus of bobtail squid encompassing around eight species. It is the sole genus of the family Idiosepiidae.Members of this genus represent no interest to commercial fisheries.-Species:*Idiosepius biserialis...
, the Oegposina lack suckers on the buccal supports, and like the Bathyteuthoidea, Idiosepiidae, and Spirulidae they have no circular muscle on the suckers.
- Suborder Oegopsina
- Family Ancistrocheiridae
- Family Architeuthidae
- Family Bathyteuthidae
- Family Batoteuthidae
- Family BrachioteuthidaeBrachioteuthidaeBrachioteuthidae is a family of squid. It contains two genera and around six species.-Species:*Genus Brachioteuthis**Brachioteuthis beanii**Brachioteuthis behnii**Brachioteuthis bowmani ***Brachioteuthis picta, Ornate Arm Squid...
- Family ChiroteuthidaeChiroteuthidaeChiroteuthids 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...
- Family Chtenopterygidae
- Family CranchiidaeGlass squidThe family Cranchiidae comprises the approximately 60 species of glass squid, also known as cranchiid or cranch squid. Cranchiid squid occur in surface and midwater depths of open oceans around the world. They range in mantle length from to over , in the case of the Colossal Squid. The common...
- Family CycloteuthidaeCycloteuthidaeCycloteuthidae is a family in the order Teuthida, comprising two genera. While physically dissimilar, molecular evidence supports the relatedness of the genera. The family is found primarily in mesopelagic tropical to subtropical waters...
- Family EnoploteuthidaeEnoploteuthidaeEnoploteuthidea is a family of squid comprising approximately 40 species in 4 genera. Most species have a mantle length ranging from 3-13 cm. Hooks are present on all arms and tentacles...
- Family GonatidaeGonatidaeThe Gonatidae, also known as armhook squid, are a family of moderately-sized squid. The family contains approximately 19 species in three genera, widely distributed and plentiful in cold boreal waters of the Pacific Ocean...
- Family Histioteuthidae
- Family Joubiniteuthidae
- Family Lepidoteuthidae
- Family LycoteuthidaeLycoteuthidaeLycoteuthidae is a family of squid comprising four known genera in two subfamilies. They are characterised by a lack of hooks and by photophores present on the viscera, eyeballs and tentacles.-Species:Subfamily Lampadioteuthinae...
- Family Magnapinnidae
- Family Mastigoteuthidae
- Family NeoteuthidaeNeoteuthidaeNeoteuthidae is a family of squid comprising four monotypic genera.-Species:* Alluroteuthis** Alluroteuthis antarcticus, Antarctic Neosquid* Narrowteuthis** Narrowteuthis nesisi* Neoteuthis** Neoteuthis thielei* Nototeuthis...
- Family OctopoteuthidaeOctopoteuthidaeOctopoteuthidae is a family of squid comprising two genera. The family is characterised by tentacles which cease to grow after the paralarval stage; and the use of a penis, instead of a hectocotylus.-Species:*Genus Octopoteuthis**Octopoteuthis danae...
- Family OmmastrephidaeOmmastrephidaeOmmastrephidae is a family of squid. It contains 3 subfamilies, 11 genera, and over 20 species.-External links:***...
- Family Onychoteuthidae
- Family Pholidoteuthidae
- Family Promachoteuthidae
- Family Psychroteuthidae
- Family PyroteuthidaePyroteuthidaeFire squid are species belonging to the family Pyroteuthidae. The family comprises two genera. Species are diurnally mesopelagic, however migrate into surface waters during the night. The family is characterised by the tentacles, which have a permanent constriction and bend near the base; and...
- Family Thysanoteuthidae
- Family Walvisteuthidae
- Parateuthis tunicata (incertae sedisIncertae sedis, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
)