''Firoloida'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

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 biological classification, genus com ...

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod mollusc in the family

Pterotracheidae Pterotracheidae is a family of medium-sized to large floating sea snails, pelagic gastropod molluscs. They are in the superfamily Pterotracheoidea along with two other similar pelagic families, the Atlantidae and the Carinariidae. These pelagic ...

, with the only species in the genus being ''Firoloida desmarestia''. This shell-less mollusc is found in tropical and sub-tropical waters in the

epipelagic zone The photic zone, euphotic zone, epipelagic zone, or sunlight zone is the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis. It undergoes a series of physical, chemical, and biological proc ...

of the world's oceans.

Taxonomy

Both genus and species were first described in 1817 by the French artist and naturalist

Charles Alexandre Lesueur Charles Alexandre Lesueur (1 January 1778 in Le Havre – 12 December 1846 in Le Havre) was a French Natural history, naturalist, artist, and explorer. He was a prolific natural-history collector, gathering many type specimens in Australia, ...

. He named the species in honour of the French zoologist

Anselme Gaëtan Desmarest Anselme Gaëtan Desmarest (6 March 1784 – 4 June 1838) was a French Zoology, zoologist and author. He was the son of Nicolas Desmarest and father of Eugène Anselme Sébastien Léon Desmarest. Desmarest was a disciple of Georges Cuvier and Alex ...

but made an error in spelling the specific name and called the mollusc ''F. demarestia''. Subsequent authors corrected this to ''F. desmarestia'', but according to the rules of precedence of scientific names, the misspelling should stand. However the

ICZN The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...

determined that ''F. desmarestia'' was preferable and substituted it for the original name.

Description

''Firoloida desmarestia'' has a proboscis, a long, transparent cylindrical body and a short, ventral tail. It has a large, rounded swimming fin, situated towards the front of the mollusc, and the opaque visceral nucleus, a mass which includes the liver, heart, gonad, sexual glands and kidneys, at the rear. Males have a sucker on the front edge of the fin, large tentacles in front of the eyes, and a tail filament, while females lack the sucker and tentacles, and have a string of eggs trailing behind them.

Distribution

''Firoloida desmarestia'' is found in warm oceanic waters and is of

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

. It has been collected from the upper of the sea and it seems to be uncommon in the north Central Atlantic Ocean, more plentiful in the Indian Ocean and rare in the northern Pacific Ocean around Hawaii.

Biology

The sexes are separate in ''Firoloida desmarestia''. A string of eggs in varying stages of development trail behind the female. Newly fertilised eggs are close to the visceral nucleus while veliger larvae, complete with a shell of two whorls and a rounded aperture, are at the far end and eventually become detached. All stages of this mollusc are

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic.

References

{{Taxonbar, from=Q13636248 Pterotracheidae Monotypic gastropod genera