View source for Lancetfish

{{Mergefrom|Alepisaurus|date=May 2008}}
:''For the [[United States Navy]] [[submarine]], see [[USS Lancetfish (SS-296)]]'' 
{{Taxobox
| name = Lancetfishes
| fossil_range = Middle [[Miocene]] - Present<ref>{{cite journal
  | last = Sepkoski
  | first = Jack
  | authorlink =
  | coauthors =
  | title =  A compendium of fossil marine animal genera
  | journal = Bulletins of American Paleontology
  | volume = 364
  | issue =
  | pages = p.560
  | publisher =
  | location =
  | date = 2002
  | url = http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class
  | doi =
  | id =
  | accessdate = 2008-01-08 }}</ref>
| image = Longnoselancetfish.jpg
| image_width = 250px
| image_caption = Longnose lancetfish, ''Alepisaurus ferox''
| regnum = [[Animal]]ia
| phylum = [[Chordata]]
| classis = [[Actinopterygii]]
| ordo = [[Aulopiformes]]
| familia = '''Alepisauridae'''
| genus = '''''Alepisaurus'''''
| genus_authority = Lowe, 1833
| species = '''''A. ferox'''''<br/>'''''A. brevirostris'''''
| binomial = ''Alepisaurus ferox''
| binomial_authority = Lowe, 1833
| binomial2 = ''Alepisaurus brevirostris''
| binomial2_authority = Gibbs, 1960
}}


'''Lancetfishes''' are large [[ocean]]ic [[predator]]y fishes in the genus '''''Alepisaurus''''' ("Scaleless lizard"), the only living genus in the family '''Alepisauridae'''.<ref>{{FishBase family | family = Alepisauridae | month = February | year = 2006}}</ref>

They grow up to two metres long. Very little is known about their [[biology]], even though they are  widely distributed in all oceans, except the [[polar region|polar]] [[sea]]s.<ref>{{cite journal | author = T. Kubota & T. Uyeno | year = 1978 | title = On some meristic characters of lancetfish, ''Alepisaurus'', collected from Suruga Bay, Japan | journal = Journal of Faculty of Marine Science and Technology, Tokai University | volume = 11 | pages = 63–69}}</ref> Specimens have been recorded as far north as [[Greenland]].<ref>{{cite journal | author = A. S. Jensen | year = 1948 | title = Contributions to the ichthyofauna of Greenland | journal = Spolia Zool. Mus. Havn. Shriff Univ. Zool. Mus. Københaven | volume = 9 | pages = 1–182}}</ref> They are often caught as by-catch for vessels long-lining for [[tuna]].

The [[genus|generic]] name is from [[Greek language|Greek]] ''a-'' meaning "without", ''lepis'' meanig "scale", and ''sauros'' meaning "lizard".

==Morphology==
Lancetfishes possess a long and very high [[dorsal fin]], soft-rayed from end to end, with the presence of an [[adipose|adipose fin]] behind it. The dorsal fin has 41 to 44 [[Fish anatomy#Spines and rays|rays]], and occupies the greater length of the back, is rounded in outline, about twice as high as the fish is deep, and can be depressed in a [[groove]] along the back. The body is slender, laterally flattened, deepest at the [[gill]] covers, and tapers back to a slender [[caudal peduncle]].  The [[mouth]] is wide, gaping to the back of the [[eye]], and each [[jaw]] has two or three large [[fang]]s, besides smaller [[teeth]].  The adipose fin recalls that of the [[smelt]] in form and location. The [[caudal fin]] is very deeply [[fork]]ed; its upper [[lobe]] is prolonged as a long [[wiktionary:Filament|filament]], and although most of the specimens seem to lose this when captured. The [[anal fin]] originates under the last dorsal ray, and is deeply concave in outline. The [[ventral fin]]s, are about halfway between the anal and the tip of the snout, while the [[pectoral fin]]s are considerably longer than the body is deep and are situated very low down on the sides. There are no [[scale (zoology)|scale]]s and the fins are exceedingly fragile.

==Species==
There are currently two [[species]] recognised as [[valid]]:
* Longnose lancetfish, ''Alepisaurus ferox'' <small>Lowe, 1833</small><ref>{{ITIS | ID = 162527 | taxon = Alepisaurus ferox | year = 2006 | date = 19 March}}</ref><ref>{{FishBase species | genus = Alepisaurus | species = ferox | year = 2006 | month = February}}</ref>
* Shortnose lancetfish, ''Alepisaurus brevirostris'' <small>Gibbs 1960</small>.<ref>{{FishBase species | genus = Alepisaurus | species = brevirostris | year = 2006 | month = February}}</ref> 

The main difference is the shape of the snout, which is long and pointed in ''A. ferox'', and slightly shorter in ''A. brevirostris''.

==Ecology==
Lancetfish have large mouths and sharp teeth, indicating a predatory mode of life. Their watery muscle is not suited to fast [[swim]]ming and long pursuit, so it is likely that they are [[ambush]] predators, using their narrow body profile and silvery colouration to conceal their presence, then use their large dorsal fin to generate large [[acceleration]], and large mouth and teeth to engulf [[prey]] before it can escape. That said, [[stomach]] content studies have revealed that they feed mainly upon [[plankton]]ic [[crustacean]]s, [[squid]] and [[salp]]s, as well as other [[fish]]. They have also been shown to be [[cannibal]]istic. They are preyed upon by [[opah]], [[shark]]s, [[albacore]], [[yellowfin tuna]], and [[fur seal]]s.

There are no [[commerce|commercial]] [[fishery|fisheries]] for lancetfishes. Their flesh is [[water]]y and [[gelatine|gelatinous]] and, although edible would prove difficult to utilise. They are caught as [[bycatch]] by [[tuna]] fisheries, and are seen as a [[pest (animal)|pest]], taking bait intended for more valuable species. Anecdotal evidence suggesting that they have an [[aphrodisiac]] effect is likely to be an [[urban myth]].

The [[tetraphyllidea]]n [[tapeworm]] ''[[Pelichnibothrium speciosum]]'' is a significant [[parasite]] of Longnose lancetfish. It seems that the species is an [[intermediate host|intermediate]] or [[paratenic]] host for the tapeworm (Scholz ''et al.'' 1998).

==Reproduction==
The [[reproductive system]] of lancetfish is something of a mystery. The [[gonad]]s of [[adolescent]]s have been shown to be [[hermaphrodite|hermaphroditic]], although there is no evidence of functional hermaphroditism in adults. They are [[oviparous]].

==References==
<references/>
* Scholz, Tomáš; Euzet, Louis & Moravec, František (1998): Taxonomic status of ''Pelichnibothrium speciosum'' Monticelli, 1889 (Cestoda: Tetraphyllidea), a mysterious parasite of ''Alepisaurus ferox'' Lowe (Teleostei: Alepisauridae) and ''Prionace glauca'' (L.) (Euselachii: Carcharinidae). ''Systematic Parasitology'' '''41'''(1): 1–8. <small>{{doi|10.1023/A:1006091102174}}</small> (HTML abstract)

==External links==
{{commonscat|Alepisauridae}}
* [http://www.abdn.ac.uk/~nhi991/alepisaurus.htm Parasites of Lancetfish]
* [http://www.gma.org/fogm/Alepisaurus_ferox.htm Presence of Lancetfish in the Gulf of Maine]

[[Category:Alepisauridae]]

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