From en.wikipedia.org:
[Family of fishes] [North American freshwater fish of the family
Lepisosteidae, not to be confused with marine garfish or needlefish of the
family Belonidae] {{Automatic taxobox | fossil_range = [Kimmeridgian] | image
= Lepisosteus oculatus.jpg | image_caption = Spotted gar<br>(_Lepisosteus
oculatus_) | display_parents = | greatgrandparent_authority = | taxon =
Lepisosteidae | authority = G. Cuvier, 1825 | subdivision_ranks = Genera |
subdivision = * [Extinct]_Nhanulepisosteus_
- [Extinct] _Britosteus_
- [Extinct] _Masillosteus_
- [Extinct] _Cuneatus_
- LEPISOSTEINI
- [Extinct] _Grandemarinus_
- [Extinct] _Herreraichthys_
- [Extinct] _Oniichthys_
- _Atractosteus_
- _Lepisosteus_
}}
GARS are an ancient group of ray-finned fish in the family LEPISOSTEIDAE.
They comprise seven living species of fish in two genera that inhabit fresh,
brackish, and occasionally marine waters of eastern North America, Central
America and Cuba in the Caribbean,[1][2] though extinct members of the family
were more widespread. They are the only surviving members of the Ginglymodi,
a clade of fish which first appeared during the Triassic period, over 240
million years ago, and are one of only two surviving groups of holosteian
fish, alongside the bowfins, which have a similar distribution.<ref name=":9"
/>
Gars have elongated bodies that are heavily armored with ganoid scales,[3] and
fronted by similarly elongated jaws filled with long, sharp teeth. Gars are
sometimes referred to as "garpike", but are not closely related to pike, which
are in the fish family Esocidae. All of the gars are relatively large fish,
but the alligator gar (_Atractosteus spatula_) is the largest; the alligator
gar often grows to a length over [6.5] and a weight over [100],[4] and
specimens of up to [3] in length have been reported.[5] Unusually, their
vascularised swim bladders can function as lungs,<ref name="FB" /> and most
gars surface periodically to take a gulp of air. Gar flesh is edible and the
hard skin and scales of gars are used by humans, but gar eggs are highly
toxic.[6][7]
** Etymology
The name "gar" was originally used for a species of needlefish (_Belone
belone_) found in the North Atlantic and likely took its name from the Old
English word for "spear".[8] _Belone belone_ is now more commonly referred to
as the "garfish" or "gar fish" to avoid confusion with the North American gars
of the family Lepisosteidae.[9] Confusingly, the name "garfish" is also
commonly used for a number of other species of the related genera _Strongylura
, Tylosurus_, and _Xenentodon_ of the family Belonidae.
The generic name _Lepisosteus_ comes from the Greek _lepis_ (λεπίς) meaning
"scale" and _osteon_ (ὀστέον) meaning "bone".[10] _Atractosteus_ is similarly
derived from Greek, in this case from _atraktos_ (ἀτρακτὀς), meaning
_spindle._<ref name="Jordan1896"/>
** Evolution
*** Evolutionary history
Gars are considered to be the only surviving members of the Ginglymodi, a
group of bony fish that flourished in the Mesozoic.<ref
name="Nhanulepisosteus" /> The oldest known ginglymodians appeared during the
Middle Triassic, over 240 million years ago.[11] Because they have the slowest
known rate of molecular evolution among all jawed vertebrates, it has also
slowed down their rate of speciation.[12] The closest living relatives of gars
are the bowfin, with the gars and bowfin together forming the clade Holostei;
both lineages diverged during the Late Permian.[13]
The closest extinct relatives of gar are the Obaichthyidae, an extinct group
of gar-like fishes from the Early Cretaceous of Africa and South America,
which likely diverged from the ancestors of true gars during the Late
Jurassic. The oldest anatomically modern gar is _Nhanulepisosteus_ from the
Upper Jurassic (Kimmeridgian) of Mexico, around 157 million years old.
_Nhanulepisosteus_ inhabited a marine environment unlike modern gars,
indicating that gars may have originally been marine fish prior to invading
freshwater habitats before the Early Cretaceous.[14][15] Although most
succeeding gar fossils are known from freshwater environments, at least some
marine gars are known to have persisted into the Late Cretaceous, with the
likely marine _Herreraichthys_ known from Mexico and the definitely marine
_Grandemarinus_ known from Morocco.[16][17]
Gars diversified in western North America throughout the Early Cretaceous.
_Atractosteus_ and _Lepisosteus_ had already diverged by the end of the Early
Cretaceous, about 105 million years ago. From western North America, gars
dispersed to regions as disparate as Africa, India, South America and Europe,
and fossil remains of gars were widespread worldwide by the end of the
Cretaceous.<ref name=":7" />
Several different gar genera survived the Cretaceous–Paleogene extinction
event, although they remained restricted to North America and Europe after
this point. One species (_Atractosteus grandei_, a relative of the modern
alligator gar) is the oldest known articulated vertebrate specimen of the
Cenozoic, with one fossil specimen dated to just a few thousand years after
the Chicxulub impact, indicating a rapid recovery of freshwater ecosystems.
Two short-snouted gar genera, _Masillosteus_ and _Cuneatus_, are known from
the Eocene in western North America and Europe, but disappear shortly
afterwards. _Lepisosteus_ and _Atractosteus_ show a similar initial
distribution and eventual contraction, but both genera dispersed to eastern
North America prior to their disappearance from western North America and
Europe, with _Atractosteus_ also dispersing further south to the Neotropics.
Eastern North America has since served as a vital refugium for gars, with
_Lepisosteus_ undergoing a diversification throughout it.<ref name=":7" />
*** Phylogeny
The following phylogeny of extant and fossil gar genera was found by
Brownstein _et al_. (2022):<ref name=":7" />
{{clade|{{clade
|1=†Obaichthyidae
|label2= LEPISOSTEIDAE
|2={{clade
|1=†_Nhanulepisosteus_
|2={{clade
|label1=†Cuneatini
|1={{clade
|1=†_Masillosteus_
|2=†_Cuneatus_
}}
|label2=Lepisosteini
|2={{clade
|1=†_Herreraichthys_
|2={{clade
|1={{clade
|1=_Atractosteus_ 80 px
|2=†_Oniichthys_ ("_Atractosteus_" _falipoui_)
}}
|2=_Lepisosteus_ 80 px
}}
}}
}}
}}
}}|style=font-size:100%;line-height:80%|label1= LEPISOSTEOIDEA}}
A slightly different phylogeny was found by Cooper _et al_ (2023):<ref
name="Cooper2023" />
{{clade|{{clade
|1=†Obaichthyidae
|label2= LEPISOSTEIDAE
|2={{clade
|1=†_Nhanulepisosteus_
|2={{clade
|label1=Masillosteinae
|1=†_Masillosteus_
|label2=Lepisosteinae
|2={{clade
|1=†_Cuneatus_
|2={{clade
|1=†_Grandemarinus_
|label2=Lepisosteini
|2={{clade
|1={{clade
|1=_Atractosteus_ 80 px
|2=†_Oniichthys_
}}
|2=_Lepisosteus_ 80 px
}}
}}
}}
}}
}}
}}|style=font-size:100%;line-height:80%|label1= LEPISOSTEOIDEA}}
** Distribution
Fossils indicate that gars formerly had a wider distribution, having been
found on every continent except Australia and Antarctica.<ref
name="Nhanulepisosteus" /> Living gars are confined to North America. The
distribution of the gars in North America lies mainly in the shallow, brackish
waters off of Texas, Louisiana, and the eastern coast of Mexico, as well as in
some of the rivers and lakes that flow into them.[18][19] A few populations
are also present in the Great Lakes region of the United States, living in
similar shallow waters.[20]
** Anatomy
*** Scales
Gar bodies are elongated, heavily armored with ganoid scales, and fronted by
similarly elongated jaws filled with long, sharp teeth. Their tails are
heterocercal, and the dorsal fins are close to the tail.<ref
name=EoF>[editor=Paxton, J.R. ]
*** Swim bladder
As their vascularised swim bladders can function as lungs,<ref name="FB" />
most gars surface periodically to take a gulp of air, doing so more frequently
in stagnant or warm water when the concentration of oxygen in the water is
low. Experiments on the swim bladder has shown that the temperature of the
water affects which respiration method the gar will use—aerial or aquatic.
They increase the aerial breathing rate (breathing air) as the temperature of
the water is increased. Gars can live completely submerged in oxygenated
water without access to air and remain healthy while also being able to
survive in deoxygenated water if allowed access to air.[21] This adaptation
can be the result of environmental pressures and behavioral factors.[22] As a
result of this organ, they are extremely resilient and able to tolerate
conditions that most other fish could not survive.
*** Pectoral girdle
The gar has paired pectoral fins and pelvic fins, as well as an anal fin, a
caudal fin, and a dorsal fin.[23] The bone structures within the fins are
important to study as they can show homology throughout the fossil record.
Specifically, the pelvic girdle resembles that of other actinopterygians while
still having some of its own characteristics. Gars have a postcleithrum—which
is a bone that is lateral to the scapula, but do not have postpectorals.
Proximally to the postcleithrum, the supracleithrum is important as it plays a
critical role in opening the gar's jaws. This structure has a unique internal
coracoid lamina only present in the gar species. Near the supracleithrum is
the posttemporal bone, which is significantly smaller than other
actinopterygians. Gars also have no clavicle bone, although elongated plates
have been observed within the area.[24]
*** Morphology
All the gars are relatively large fish, but the alligator gar (_Atractosteus
spatula_) is the largest. The largest alligator gar ever caught and
officially recorded was [8] long, weighed [327], and was [47] around the
girth.[25] Even the smaller species, such as _Lepisosteus oculatus_, are
large, commonly reaching lengths of over [60], and sometimes much longer.<ref
name=Kodera>Kodera H. _et al._: Jurassic Fishes. TFH, 1994,
[0-7938-0086-2][date=June 2015]
** Ecology
Gars tend to be slow-moving fish except when striking at their prey. They
prefer the shallow and weedy areas of rivers, lakes, and bayous, often
congregating in small groups.<ref name="filaman.ifm-geomar.de"/> They are
voracious predators, catching their prey in their needle-like teeth with a
sideways strike of the head.<ref name=Kodera/> They feed extensively on
smaller fish and invertebrates such as crabs.<ref name="fishbase.org"/> Gars
are found across much of the eastern portion of North America.<ref
name="filaman.ifm-geomar.de"/> Although gars are found primarily in freshwater
habitats, several species enter brackish waters and a few, most notably
_Atractosteus tristoechus_, are sometimes found in the sea. Some gars travel
from lakes and rivers through sewers to get to ponds.<ref
name="filaman.ifm-geomar.de"/>[26]
** Species and identification
The gar family contains seven extant species, in two genera. This list also
includes definitively known fossil taxa, common names for which are based on
Grande (2010):<ref name=FB>[family=Lepisosteidae][27]
{{cladogram |title=Cladogram of living gars[28]
|{{clade|style=font-size:80%;line-height:100%;width:300px; |label1=
LEPISOSTEIDAE |1={{clade
|label1=_Atractosteus_
|1={{clade
|1=_A. tropicus_
|2={{clade
|1=_A. tristoechus_
|2=_A. spatula_ 50 px
}}
}}
|label2=_Lepisosteus_
|2={{clade
|1={{clade
|1=_L. oculatus_
|2=_L. platyrhincus_
}}
|2={{clade
|1=_L. osseus_ 50 px
|2=_L. platostomus_ <span style="{{MirrorH}}">50 px</span>
}}
}}
}}
}}
}}
Family LEPISOSTEIDAE
- Genus † _Nhanulepisosteus_ <small> Brito, Alvarado-Ortega & Meunier, 2017 </small>
- Genus † _Britosteus_ <small> Martinelli _et al_ 2025 </small>
- Genus † _Masillosteus_ <small> Micklich & Kappert, 2001 </small>
- Genus † _Cuneatus_ <small> Grande , 2010 </small> (cuneatus gar)
- Tribe LEPISOSTEINI
- Genus † _Herreraichthys_ <small> Alvarado-Ortega _et al_ 2016 </small>
- Genus † _Grandemarinus_ <small> Cooper _et al_ 2023 </small>
- Genus † _Oniichthys_ <small> Cavin & Brito, 2001 </small>
- Genus _Atractosteus_ <small> Rafinesque , 1820 </small>
- †_Atractosteus atrox_ <small> ( Leidy , 1873) </small> (Green River atrox gar)
- †_Atractosteus grandei_ <small> Brownstein & Lyson, 2022 </small> [29]
- †_Atractosteus messelensis_ <small> Grande, 2010 </small>
- †_Atractosteus simplex_ <small> (Leidy, 1873) </small> (simplex gar)
- _Atractosteus spatula_ <small> ( Lacépède , 1803) </small> ( alligator gar )
- _Atractosteus tristoechus_ <small> ( Bloch & J. G. Schneider , 1801) </small> ( Cuban gar )
- _Atractosteus tropicus_ <small> Gill , 1863 </small> ( tropical gar )
- Genus _Lepisosteus_ <small> Linnaeus , 1758 </small>
- †_Lepisosteus bemisi_ <small> Grande _,_ 2010 </small> (Green River longnose gar)
- †_Lepisosteus indicus_ <small> ( Woodward , 1890) </small> (Indian gar)
- _Lepisosteus oculatus_ <small> Winchell , 1864 </small> ( spotted gar )
- _Lepisosteus osseus_ <small> ( Linnaeus , 1758) </small> ( longnose gar )
- _Lepisosteus platostomus_ <small> Rafinesque , 1820 </small> ( shortnose gar )
- _Lepisosteus platyrhincus_ <small> DeKay , 1842 </small> ( Florida gar )
*** Alligator gar
[Alligator gar] alt= The largest member of the gar family, the alligator gar
_( Atractosteus spatula_), can reach over [8] (although 10-foot individuals
are possible, and likely exist) and weigh over [300].[30][31] Its body and
snout are wide and stocky, and it was named "alligator gar" because locals
often mistook it for an alligator.<ref name=":05"/>[32] The species can be
found in Texas, Oklahoma, Louisiana, the Mississippi River, Ohio, the Missouri
river, and the southern drainages into Mexico.<ref name=":8" /><ref name=":1"
/> Its habitat consists of lakes and bays with slow currents.<ref name=":8" />
The gars grow rapidly when young and continue to grow at a slower rate after
reaching adulthood.[33] They are deep green or yellow in color.<ref name=":8"
/><ref name=":1" /> Recreational fishing of the alligator gar became popular
due to its massive size and its meat is sold for food.[34] Over five decades
of overfishing have brought it close to extinction,<ref name=":1" /><ref
name=":10" /> and man-made dams have contributed to this loss by restricting
the gar's access to the flood plain areas in which it spawns.<ref name=":12"
/> Some U.S. states have enacted laws to combat overfishing, and
reintroduction programs are being carried out in some states, such as
Illinois, where human activity has extirpated the gar.<ref name=":1" /><ref
name=":10" /> Before being released, each gar must meet a length requirement
to ensure that it has the best chance of survival in the wild.[35] Some
states, such as Texas, restrict the number of gar that may be caught in a day,
the season in which they may be caught, and the equipment anglers may use to
catch them. Some states also impose a minimum length requirement to prevent
gar from being caught at too early an age.[36] Scientists have found that the
alligator gar can help maintain ecosystem balance by eating invasive species
such as the Asian carp, and their success in a particular area can show
scientists that area may also make a suitable habitat for other migratory
species.<ref name=":15"/>
*** Florida gar
[Florida gar] The Florida gar _( Lepisosteus platyrhincus_) can be found in
the Ocklockonee river, Florida, and Georgia,[37][38] and prefers muddy or
sandy bottoms with bountiful vegetation.<ref name=":2" />[39] It is commonly
confused with its cousin, the spotted gar.<ref name=":2" /> Uneven black spots
cover its head, body, and fins.<ref name=":2" /><ref name=":13" /> Green-brown
scales run along the back of its body, and the scales on its underbelly are
white or yellow.<ref name=":2" />[40] This coloration, which blends well with
the gar's surroundings, allows it to ambush its prey.<ref name=":2" /><ref
name=":14" /> The Florida gar has no ganoid scales on its throat.<ref
name=":2" /> Female Florida gars grow to lengths between [13 and 34], bigger
than their male counterparts.<ref name=":2" /><ref name=":14" />
*** Spotted gar
[Spotted gar] alt= The spotted gar _( Lepisosteus oculatus )_ is a smaller
species of gar,<ref name=":05"/> measuring just under four feet long and
weighing 15 pounds on average.<ref name=":05"/> Like Florida gars, female
spotted gars are typically larger than male spotted gars.[41] This gar has
dark spots covering its head, body, and fins.<ref name=":05"/> Its body is
compact, and it has a shorter snout.<ref name=":05"/> It prefers to live in
clearer shallow water with a depth of [3-5],[42] and to surround itself in
foliage.<ref name=":74"/><ref name=":3" /> Its habitat ranges from the waters
of Lake Michigan, the Lake Erie Basin, the Mississippi River System, and river
drainages along the northern coast of the Gulf of Mexico from the Nueces River
in Texas east to the lower Apalachicola River in Florida.<ref name=":3" />[43]
It shares its habitat with the alligator gar, its main predator. These
smaller gar live an average of 18 years.<ref name=":3" />
*** Shortnose gar
[Shortnose gar]
The shortnose gar (_Lepisosteus platostomus )_ is found in the Mississippi
River Basin, Indiana, Wisconsin, Montana, Alabama, and Louisiana.[44] It
prefers to live in lakes, swamps, and calm pools.<ref name=":74"/><ref
name=":4" /> The shortnose gar takes its name from its snout, which is shorter
and broader than that of other gar species.<ref name=":05"/><ref name=":4" />
Like the longnose gar, it has one row of teeth. The upper jaw is longer than
the rest of its head.<ref name=":4" /> The shortnose gar is deep green or
brown in color, similar to the alligator gar.<ref name=":05"/><ref name=":4"
/> Depending on the clarity of water, spots can be present on the caudal,
dorsal, and anal fins.<ref name=":4" /> The shortnose gar has a lifespan of 20
years, reaches up to [5] in weight,[45] and grows to lengths of [24-35].<ref
name=":92"/><ref name=":5" /> It consumes more invertebrates than any other
gar,<ref name=":4" /> and their stomachs have been found to contain higher
Asian carp content than any other native North American fish.<ref name=":15"/>
*** Longnose gar
[Longnose gar] alt= The Longnose gar _( Lepisosteus osseus )_ has a longer,
narrower, more cylindrical body,<ref name=":05"/>[46] and can be distinguished
from other species of gar by its snout, which is more than twice the length of
the rest of its head.[47][48] It can reach up to 6 feet and 8 inches in length
and weigh up to [35-80].<ref name=":05" /><ref name=":6" /> Like the shortnose
gar, it has only a single row of teeth.<ref name=":6" /><ref
name="dec.ny.gov"/> Unlike its relatives, it enters brackish water from time
to time.<ref name=":74"/><ref name=":6" /> Females are larger and live longer
than the male longnose gar.<ref name=":11" /><ref name=":6" /> Females live 22
years, and males about half as long.<ref name=":6" /> There are spots on the
head, dorsal, anal, and caudal fins.<ref name=":05" /><ref name=":6" />[49]
Depending on the water clarity, the longnose gar comes in two colors.<ref
name=":6" /> In clear water, they are a dark deep green color. In muddy
waters, it is more brown in color.<ref name=":6" /> Edges of the ganoid scales
and in between are black.<ref name=":6" /><ref name=":16" /> These types of
gar are occasionally fished by locals, and blamed for eating other fish in the
rivers.<ref name=":11" /><ref name=":6" /> The longnose gar has a large range
of territory in North America, into the Gulf of Mexico.<ref name=":6" /><ref
name=":16" /> Located in Florida, Quebec, all Great Lakes except Lake
Superior, Missouri, Mississippi, Texas, and northern Mexico.<ref name=":6"
/>[50]
** Roe
The flesh of gar is edible, but its eggs contain an ichthyotoxin, a type of
protein toxin which is highly toxic to humans.[51][52] The protein can be
denatured when brought to a temperature of 120 degrees Celsius,[53] but as the
roe's temperature does not typically reach that level when it is cooked, even
cooked roe causes severe symptoms. It was once thought that the production of
the toxin in gar roe was an evolutionary adaptation to provide protection for
the eggs, but bluegills and channel catfish fed gar eggs in experiments
remained healthy, even though they are the natural predators of the gar eggs.
Crayfish fed the roe were not immune to the toxin, and most died. The roe's
toxicities to humans and crayfish may be coincidences, however, and not the
result of explicit natural selection.<ref name=":0" />
** Significance to humans
Several species are traded as aquarium fish.<ref name="Kodera" /> The hard
ganoid scales of gars are sometimes used to make jewelry whereas the tough
skin is used to make such items as lamp shades. Historically, Native
Americans used gar scales as arrowheads, native Caribbeans used the skin for
breastplates, and early American pioneers covered the blades of their plows
with gar skin.[54] It is suspected that gars have an unusually strong DNA
repair apparatus. If confirmed by further studies, it could be used in
medical treatments against human diseases like cancer.[55]
Not much is known about the precise function of the gar in Native American
religion and culture other than the ritual "garfish dances" that have been
performed by Creek and Chickasaw tribes.[56]
** References
[Reflist]
** External links
- _Family Lepisosteidae_ (see http://www.fishbase.org/Summary/FamilySummary.cfm?ID=34)
[Actinopterygii] [from1=Q506144]
Category:Lepisosteidae Category:Fish of Central America Category:Fish of North
America Category:Extant Late Jurassic first appearances Category:Taxa named by
Georges Cuvier Category:Freshwater fish