An Introduction to Lepisosteidae

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xander

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Author(s): Pejelagarto (Richard Kik IV)
Edited and Arranged by Xander (Alexander Eng)


*** All Information Copyright 2010 the authors and www.MonsterFishKeepers.com OR used with permission. All Images Copyright 2010 the correspondingly credited and used with permission.

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A few essential basics on Gar

A few basics to understand about Gar (And how to get the best out of this forum):

1. There are seven species and two genus: that ranks gar as being pretty low in species diversity. Now with this said there truly is very little reason why one cannot simply ID these fish or at least get a rough idea of genus and species group. Yes some juvenile fish and those of the spotted gar group (Lepisosteus oculatus, L. platyrhincus) can be a bit tricky but there really is no rocket science behind identification of these fish. There is an abundance of information on the specific ID traits of all seven species (plus a few hybrids) both here and elsewhere on the net. There is little excuse to be totally unaware of or not have a slight idea of which species you have or wish to obtain.

2. Identification of these fish is important if you are to attempt keeping one. Gars are not a one size fits all fish and you can not treat one in the same manner you treat and keep another. It has long been assumed and wrongly so that you can just treat all the same. This is really a rather asinine concept. The more that we have been learning about gars the more it is becoming very clear that each species is very different and each species requires a different method of husbandry.

3. A gar is not just a gar because it has the common name "gar"... Gar are Lepisosteids. Lepisosteids are characterized by having a elongate bony covered snout and head, Nostrils on the end of the snout, Thick enamel coated ganoid scales, Rounded caudal fin with Vertebrate extending up and along the top edge (Heterocercal tail). These specific traits are only found together in Lepisosteids any other fish called a “gar” that lacks any of the above traits is NOT a gar….Why do gar (Lepisosteid) keepers get riled when NON gar are the focus of a “gar” conversation? This is simple… THEY ARE NOT GAR and the purpose of a forum such as this that focuses on Lepisosteids in particular is to discuss Lepisosteids not tetras. Lumping these “false gar” with “true gar” is also confusing and inappropriately lumps totally different animals on the basis of what is essentially a useless name…

4. Common names are generally useless when discussing these fish. If you can not ID the species and use the correct scientific vernacular get it from someone you know has it and can tell you correctly. Alligator gar or “fill in blank” gar will not cut it if you wish to get detailed and specific info about a fish in this family. For a very long time the general rule has been to just make something up rather than ID these fish. You will quickly find when asking questions about these fish that those who do know about them do not regularly use common names and will question you as to the ID of your fish quickly if it is not clear what species is being discussed. There is good reason for this and it goes right back to point 2.. Different species require a different approach to husbandry. It is inappropriate and false to lump all these species into one pigeonhole. If someone does do this their advice or comments are best taken with a grain of salt and you would be wise to re-check the information yourself.

Really myself and some others enjoy talking about and disseminating information about these fish and will do so enthusiastically if asked right with details that can allow a detailed answer. With just a few moments on your part to avoid miscommunication and to make sure that communication is clear we can all learn quite a lot. Being lazy about even looking at available resources will quickly not be looked at very positively. Gars are a specialized group of fish and there is a small but dedicated core that specialize in them. We will not bother to answer the same question 900 times when we just did it yesterday.

Please do a small amount of research by looking over past topics and search the net a bit before asking what are essentially simple questions. (I.E What do they eat?, How big do they get?, what gar is this? can I keep one in a 55 gallon? )

Reference:

Monsterfishkeepers.com

 

xander

Manjuari
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Sep 6, 2007
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Author(s): Pejelagarto (Richard Kik IV)
Photos by: Pejelagarto
Edited and Arranged by Pejelagarto

*** All Information Copyright 2010 the authors and www.MonsterFishKeepers.com OR used with permission. All Images Copyright 2010 the correspondingly credited and used with permission.

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What is a gar and what is not one


So just what is a Gar?
And just why is it important to distinguish a Lepisosteid from other fish that may share their common name?

First lets tackle “What is a Gar?”

In our use, we are calling a gar any of the number of fish that belong to the ancient order of fish known as Semionotiformes. Semionotiformes first distinguished themselves from related Neopterygii some 300 or 250 million years ago with a small genus of interesting fish called Obaichthys. Obaichthys was distinctive for it had a different scale arrangement from other Neopterygii. In Obaichthys the scales lacked a then common dentine layer. This was where the Lepisosteidae where born into being. Obaichthys looked much like today’s Atractosteus gars. It was an elongate fish with set back dorsal and anal fins, Caudal fin was Heterocercal, and the nose of the fish was elongate with a set of sharp needle like teeth in two rows on the upper jaw and one in the lower. Unlike modern gar however it had a movable premaxillary.

Gars (Lepisosteidae) then transitioned and evolved out into two genus in the Cretaceous 145 some million years ago. (Atractosteus and Lepisosteus). Both genus where wide spread during much of the late Mesozoic and through the catastrophic extinction that brought in the Cenozoic. Surviving members evolved some 75 MYA and have until today existed unchanged.

Today seven species exist only in North and Central America and on the Island of Cuba. In their glory days of the late Mesozoic, they ranged throughout North America, South America, East Asia, Africa and Europe.

Gar morphology:
Lepisosteids have unique morphology that is quite different from the later evolving and less advanced Teleosts species that have come to take over the earth. As mentioned an important trait is that the scales are unlike other Actinopterygii fishes (Living examples being Polypterids and Sturgeon) and other Neopterygian Fish (Bowfin). Gar scales have a cosmine lower layer that has a dense ganoin layer on top but it lacks the Dentine layer found in previous fish. Other traits are the presence of a spiral valve at the end of the intestine, Vascularized air bladder (that is essentially a “lung”), heterocercal tail, and opisthocoelous (concave posteriorly and convex anteriorly) vertebra.

OK…. That is a gar by definition for the most part..
A definition of Lepisosteidae and what it is that defines them...

Now we define Not gars... provide examples and discuss just why it is important to distinguish them..



The above two fish look alike but just how alike are they???
They are in fact nothing alike...

Top fish is a Belonid.

Some of these fish are occasionally termed gars. Five families of fishes make up the order Beloniformes: Adrianichthyidae (ricefishes), Belonidae (needlefishes), Scomberesocidae (sauries), Exocoetidae (flyingfishes), and Hemiramphidae (halfbeaks).
(Closely related are also Rainbowfishes)

Oldest known is 50 MYA. These fish are fricking youngin Teleosts and have no relationship to Lepisosteids at all. What they do have in common is elongated jaws with teeth in some genus and that is about it. None have any characteristics of Lepisosteids morphologically or behaviorally. There is nothing about them that that is in anyway comparable. Some of the Needlefish are called “gar” but they are far from being gars.

Same here..


Do the above fish look anything alike? Sure they might in some way....

One However is an Atractosteus and the other is a Tetra.. If you tried to keep these fish on equal terms you would kill them both. Both require specific care and neither is in any way related to the other. Gar are not Tetras They are GAR and Lepisosteids should be respected as such...Ctenolucius are tetras and have no traits morphologically or behaviorally with an Atractosteus or any lepisosteid for that matter. The only thing they have in common is the retarded Common name "Rocket gar" with Gar as an association.

Lepisosteids, Belonids and Characins are very different fish. They are not related in any way and they are very very different animals. The common name "Gar" is not very relevant and you can not exchange them when discussing this group of fishes. Gars are Lepisosteids and not the other common name groups.

The Lepisosteids are the only primitive fish group and the only ones with relevence to this subforum.
 

xander

Manjuari
MFK Member
Sep 6, 2007
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555
Singapore
Author(s): Xander (Alexander Eng)
Photos by: Xander
Edited, Arranged, and Referenced by Xander


*** All Information Copyright 2010 the authors and www.MonsterFishKeepers.com OR used with permission. All Images Copyright 2010 the correspondingly credited and used with permission.

No material (listed above) may be reproduced without permission.

Brief Information on Gars

Order:
Lepisosteiformes

Family:
Lepisosteidae

Genus:

Lepisosteus
Lepisosteus oculatus – Spotted gar
Lepisosteus osseus – Longnose gar
Lepisosteus platostomus – Shortnose gar
Lepisosteus platyrhincus – Florida gar

Atractosteus
Atractosteus tropicus – Tropical gar
Atractosteus tristoechus – Cuban gar
Atractosteus spatula – Alligator gar

Hybrids:

Crocodile gar type I – Alligator gar x Shortnose gar
Crocodile gar type II – Alligator gar x Spotted gar
Crocodile gar type III – Alligator gar x Longnose gar
Medium-nose gar – Longnose gar x Shortnose gar

Distribution:
“Eastern North America (from southern Quebec) to Costa Rica; Cuba” (Fishbase.org)

Description:
Lepisosteidae are primitive fish that have been unchanged for 75 million years. They have elongated bodies and jaws and are clad with thick, overlapping Ganiod scales. Gars have a vascularised swim bladder that acts as a lung. This allows them to survive in poorly oxygenated waters. The flesh of Lepisosteidae is edible although the roe is toxic.

References:


Fishbase.org


Lepisosteidae.net

Zoo Lab

 

xander

Manjuari
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Sep 6, 2007
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Here are some solid references/resources for Information on Gar species. These are existing references, so they will be linked to this thread, but images will not be reproduced unless done so by the authors.

Thanks and good luck--
--solomon

Important Gar References/Resources:


Lepisosteidae.net
(illustrations of all gar species, photo IDs coming soon)

GARS - PrimitiveFishes.com
(photos of all gar species - adults, juveniles, hybrids)
 

xander

Manjuari
MFK Member
Sep 6, 2007
8,535
57
555
Singapore
Author(s):
Photos by:
Edited, Arranged, and Referenced by


*** All Information Copyright 2010 the authors and www.MonsterFishKeepers.com OR used with permission. All Images Copyright 2010 the correspondingly credited and used with permission.

No material (listed above) may be reproduced without permission.

Sexing and Breeding Gar
 
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