Polypterids an introduction and primer 4.0

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Edit 4.0 - Fixed formatting, grammatical errors and layout - Done by Hendre

Introduction
Polypterids are the sole survivors of the Order Polypteriformes whose distribution included Africa and South America and can be dated back at least 100 million years in the fossil record. They are among the most primitive of the ray-finned fishes (Actinopterygii) the dominant group of fishes today.

The elongate body of a Polypterid range from 10 inches to 3 ft long with adult size depending on the species. Their bodies are round in cross section becoming compressed near the tail. They have a powerful body with the spine midline through the body and four large muscles flanking it, ending in a Diphycercal Tail.

Polypterids are covered by multilayered scales,rhomboid in shape and have articulating peg and socket joints between them,With an outer layer of ganoine( (an inorganic bone salt) a middle layer of dentine and a layer of isopidine and an inner dermal, cosmine bony layer and are referred to as ganoid scales. Only the bowfin (Amiidae) share this particular ganoid scale construction.
The dorsal fin of the Polypterids is split into a row of small, sail-like finlets that are erected individually when the animal is agitated or feels threatened.

Polypterids are also unusual among ray-finned fishes in possessing only four rather than five gill arches.

Newly hatched Polypterids have feathery gills, not unlike lungfishes, which may be retained for some time. Most individuals lose them by the time they have reached 2-3 inches. Polypterids are suited to life in warm stagnant backwaters and swamps where oxygen levels are low. They have adapted to these habitats by the use of a primitive form of lungs which allow them to breathe atmospheric air as opposed to being solely dependent on dissolved oxygen in the water. Bichirs are bimodal in respiratory function--they have both gills and well vascularized lungs--and can survive using either.

The Polypterids are shallow water species often swimming in the weeds and plants near shores and banks of Central and West African freshwater lakes and rivers. They seem to vary between diurnal and nocturnal depending on species in the wild.

They are sometimes caught as a food fish and are said to be quite tasty.

In addition to the ten species and six subspecies of Polypterus, the family also includes the ropefish, Erpetoichthys calabaricus, similar in character and distribution but lacking the pelvic fins and with a longer eel-like form.

All species of Polypterus require the same care just the size of the tank changes bigger species bigger tanks.

Polypterids tend to be long lived averaging 10-15 years in captivity.

 

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Species and sizes
maximum known sizes often smaller in captivity

Upper Jaw Species-Upper jaw protrudes past lower jaw
P. palmas palmas ('palmas' bichir)- 13"
(subspecies)P. palmas polli ('marbled bichir)- 14"
(subspecies) P. palmas buettikoferi ('buettikoferi' bichir)- 13"
P. ornatipinnis ('ornate' bichir)- 27"
P. delhezi ('armoured' or 'delhez's' bichir)- 14"
P. senegalus senegalus ('Senegal' or 'Cuiver's' bichir)- 12"
(possible subspecies)P. senegalus meridionalis- 12"+
There is, Also the possibility of a third member of the Polypterus senegalus
group that is found in the Nile River
P. retropinnis ('retropinnis' bichir)- 14"
P .mokelembembe
P. weeksi ('week's' bichir)- 20"
P.teugelsi (found only in the Cross river)-16.75''
E. calabaricus ('Ropefish')- 15"-30" (Closer to 15''-20'' in captivity)

Lower Jaw Species-Lower protrudes past upper jaw
P. endlicheri endlicheri ('saddled' or 'red' bichir)- 32", possibly more
(subspecies)P. endlicheri congicus ('giant' or 'congo' bichir)- 39"
P. Bichir lapradei ('Lapradei' bichir)- 24"
P. bichir bichir-30+ ''
P.ansorgii-28-30+''

There are a couple of as-yet-undescribed (scientifically) Polypterids

Variations
There are variations of the above including
short bodied:
longfinned:
albinism: Albino Polypterids have a pink/ white body with red eyes if they are a species with pronounced markings
these are often yellowish in color
leucistic: Leucistic (platinum) are silver/whitish bodies with black eyes.

 

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WHY BICHIR?

When Europeans (French) discovered the genus Polypterus in 1809 it had already been known along the Nile since the time of the pharoahs. The local peoples referred to them as bichirs (unknown pronunciation and spelling). While unable to come up with an exact meaning for the word it was most likely a descriptive term (''whip'' has been suggested) for this type of fish.

The French most likely pronounced it as phonetically as possible to the orginal native word and came up with bee-sheer as a pronunciation and spelled 'bichir'. Since this would be the name of these fish for
several years until they were scientifically described and put into the proper family it became an accepted common name.

However the correct English pronunciation is up for grabs. Several dictionaries all have their own pronunciation including the below:
bee cher
beech er
bikir
biker
bercheer
bi cher
bir chir is common in England
Also known by the common name lobed fin pike,dinosaur eel.
The name Polypterus : poly=many + pterus=fins and is pronounced po-lyp'-terus.

PRONUNCIATION(from fruitbat/Joe)
In general, a single 'i' at the end of a species name should be pronounced as a long 'i' ('eye'). For example, endlicheri would be pronounced 'end-lick-er-eye' or 'end-lich-er-eye'.
A species name that ends with two 'i's (like weeksii) would be pronounced with the first 'i' sounding like a long 'e' and the second 'i' as a long 'i'....hence - 'weeks-ee-eye'.
The correct pronunciation for Polypterus is 'po lip ter us' with many people putting the accent on the 'lip'.
Putting it all together, Polypterus ansorgii would then be pronounced: 'Po-lip-ter-us an-sorg-ee-eye'. Polypterus delhezi would be pronounced: 'Po-lip-ter-us del-hez-eye'.

Polypterus bichir bichir: bike-er bike-er

Polypterus bichir lapradei: la-prade-e-i

Polypterus delhezi: del-hez-i

Polypterus endlicheri endlicheri: end-lick-er-i end-lick-er-i

Polypterus endlicheri congicus: end-lick-er-i con-ji-cuss

Polypterus mokelembembe: moe-kay-la-em-bem-bay(mokèlé-mbèmbé)

Polypterus palmas buettikofferi: palm-us but-i-coff-er-eye

Polypterus palmas palmas: palm-us palm-us

Polypterus palmas polli: palm-us poll-i

Polypterus retropinnis: retro-pin-nis

Polypterus senegalus: sen-eh-gal-us

Polypterus teugelsi: too-gulls-i

Polypterus weeksii: weeks-ee-i

Polypterus ansorgii: an-sorg-ee-i

Polypterus ornatipinnis: or-nate-eh-pin-nis

Erpethoichthys calabaricus (Reed or Rope Fish) : Er-pet-oh-ick-these cal-a-bear-ih-cuss

 

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Sound production

P.senegalus and P.retropinnis were studied and found to make two distinct sounds. A thumping noise and a moan.
The mechanics are unclear at this time.
Thumps: Occured during close encounters by conspecifics one or both would raise their dorsal fins and emit thumps the sound energy was strongest between 100-200z with a maximum rate of 3 thumps per second and decreasing as one conspecific moved away from the other.
Moans could be heard even without technical equipment .As conspecifics swam rapidly away from eachother or were startled.
Also reported to makes the same sounds(but not studied) are P. endlicheri, P.palmas polli, and P. ornatipinnis
(Abstract in Icthyological notes: Copeia 1988 (4) pp. 1076-1077).

 

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Did you know

1. Did you know until the last few years all bichirs were wild caught?
2. Did you know most bichirs come from a band across Africa along following the equator from 10 degrees north to 10 degrees south of it?
3. Did you know females are generaly larger than males?
4. Did you know bichirs can be traced back some 96 million years but are thought to be even older
5. bichirs have two plate-like structures on the bottom of their lower jaw; these are known as 'gular plates' and are thicker bony structures which aid the bichir in crushing food; the bowfin (Family Amiidae) also has this structure in the form of a single large gular plate, also used for compressing food
6. While the sex of bichirs can be determined at 7-9 inches,Some species may not be sexually mature till 6 years of age
7. While the scales of Lepisosteidae species(Gars) may look the same they lack the middle dentine layer present in Polypterids and Amiidae.
8. Importation or possesion is prohibited in Hawaii
9. According to the USGSa few specimens of Polypterus delhezi have been caught in SE Florida
10. A country in Africa(Ivory Coast) had a Polypterus endlicheri endlicheri on a stamp in 1986
11. Polypterus senegalus, the longnose gar (Lepisosteus osseus) and the bowfin (Amia calva) had gulonolactone oxidase activity in the kidney and thus can synthesize ascorbic acid(VITAMIN C) (Journal of Fish BiologyVolume 57 Issue 3 Page 733 - September 2000)
12. Use dorsally placed spiracle to exhale (not inhale like skates and rays)(Ichthyology Spring 1999 T. Turner Lecture 12)

 

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Polypterid fossil record
The polypterid fossil record was for a long time reduced to some scarce, disarticulated bones, mainly scales, found in various African deposits covering a wider area than the actual geographical distribution. With the discovery, on one hand, of polypterid scales, vertebrae, dermal bones of the cranium and dorsal spiny rays in South America and, on the other hand, of scales and numerous dorsal spiny rays in Niger and Sudan, and two articulated fossils in Morocco, the story of the polypteriformes has revealed some of its mysteries. The discovery of isopedine between dentine and bony basal plate in the scales of living and fossil polypterid species is considered a synapomorphy of the group, and has been an important aid in discriminating polypterid scales from other ganoid scales(Fish and Fisheries Volume 2 Issue 2 Page 113 - June 2001)

 

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Purchasing Bichirs

There are basicly three ways to purchase bichirs:

1. Wait around hoping your favorite store gets some in
2. Ask if they can order them from their suppliers most good stores can be very accomodating this way
3. Online there are number of suppliers.The drawback to this and the above is someones picking your fish or you.

This said lets say you found a store with a number of bichirs of the same species what do you look for:

1. Clear eyes
2. All fins present,(pectoral,pelvic,anal.and dorsal finlets)
3. No noticable fungal or parasitic problems
4. Look for one thats more active than the others,
5. Make sure it mouth is fine and nostrils (2) are present
6. Color or pattern

And ask a couple questions how long have they been in the store? This can be very important. Most
Bichirs are wild-collected, many by native plant poisons, others through trapping and often starved before
shipping in crowded, questionable conditions. Some won't make it, sorry to say. Most that are not going to
will die within a week or two. The best way to insure your fish will is to wait that 2 weeks either place it on hold
or make sure it been there that two week period. Other questions are they eating? And what are they being fed?
And ask to see it eat.

 

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Aclimating new fish
Depending on how you purchased your new bichir aclimating can be done in two different ways. If purchased locally you can simply float the bag to match the temperature, you also have to adjust the fish to the new water chemistry. After the temperature is matched open the bag and slowly add the new tanks water to the bag over the next hour or two. This will allow the fish to adjust to its new water chemistry slowly, preventing whats known as PH shock. This is one of the most common causes of death to newly purchased fish. If purchased online and lengthy shipping is involved there is a second way to aclimate your new fish.

It is called dripping. Dripping is usually done with an airline tubing. First of all you empty the fish from the bag into a small bucket....take precautions to prevent fish from jumping out and provide aeration as needed. You siphon water from your tank into the bucket with the airline tube. Once a steady flow is achieved you then knot the tubing close to the outlet so that the water flow is restricted and reduced to a trickle. This can be allowed to run anywhere from 30 minuites to 3 hrs. While in the bucket this is the time consider Prophylactic treatment.

 

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Prophylactic treatment

What is it ?
Simply put its a preventative step,Its purpose is to prevent any disease or parasitc transmission between newly aquired fish and established tankmates.


Why?
Should it be considered? well in the case of bichirs since many species are still wild caught they may harbor parasitic organisms it is for this reason a prophylactic treatments may be considered.

What's involved?

Salt bath
First, give them a prophylactic salt bath right in the transfer bucket. Separately dissolve 5 tablespoons of common salt (NaCl) per gallon of water. Add 1/3 the solution to the transfer bucket, wait ten minutes and add another 1/3 wait 10 minutes add the other 1/3 . Keep an eye on the new fish and remove any at the first signs of distress. Leave them covered in the bucket for a further 15 to 30 minutes. Many public aquaiums widely use a saltwater dip for all their new freshwater arrivals, at full-strength salinity (35 parts per thousand), for ten minutes. A major reminder is that common salt (NaCl) doesn't affect the pH buffer, but "Marine" salt and so-called "Aquarium" salt does. A change in pH, rather than the salt itself, accounts for most of the stress in a salt dip,If your fish do show acute stress you'd remove it, net them out and transfer them to the quarantine tank. Hopefully they should have left behind most of or all their external parasites (this will not eliminate encysted parasites). Then, give the new arrivals 24 to 48 hours to settle down. Give them time to recover from stresses, get some color, and get their respiration rate back to normal, while you examine them.

Chemical
The first treatment in the quarantine tank should be an anti-helminthic (anti-nematode) treatment for intestinal parasites. I use "JUNGLE LABS PARASITE CLEAR'' or "JUNGLE LABS PARASITE GUARD", both contain broad spectrum anti-helminthic (anti-nematode) at recommended dosage this should elimanate any internal or external parasites.While there are other drugs I haven't used them and the ones listed are available online from the major suppliers. To get the correct amount of water. A tank holds measure the inside of the tank and calculate with those numbers. Gravel displaces 2.4 gallons per 50 pounds. This is useful in calculating the true water capacity of your aquarium
Sources include TFH, April 1998

 

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Quarantine
Noun: a state of enforced isolation.
Why should we quarantine? In particular our bichirs are mostly wild caught this can lead them to be carriers of all kinds of nasty things.And the importers can't catch all the bad stuff some of which may not be evident for several days or weeks. It is far easier to observe and fix one fish than risk infecting an established tank.

There are two ways to quarantine new fish one is a basic bare tank. This is not a long term display tank, it is meant to be emptied and cleaned and stored after the quarantine period. It can also do duty as a hospital tank if and when the need arises. A tank sized to fit the specimen should be used for this purpose. Remember, this is for temporary use.
Why don't we quarantine? Simply because we are in a hurry to show off our new fish. However after you have done this and wind up with a tank of sick or dying fish you will understand the importance of quarantining fish. This applies to store bought feeders also.

The Tank 1
This is as simple as it gets: filter, heater, and some plastic plants or some kind of structure to
hide in. Simple, like I said its not long term. 4 weeks in most cases should be fine. It isn't pretty but
it is not supposed to be .

The Tank 2
You setup the tank with substrate, plants, decorations as you would any display tank and add the new fish and nothing more. Any future purchases for this tank will need to QT in a tank 1 setup. The Hospital Tank Is basically a tank 1 setup its use is to isolate and treat sick or damaged fish not long term. Use as little decoration as possible and the amount of water should be measured so the correct amonut of medication is administered contrary to popular belief all tanks are incorrectly sized and hold somewhat less water than stated.