Polypterids or bichirs 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 depending on the species and round in cross section becoming compressed near the tail.They have a powerful body with the spine midline thru the body and four large muscles flanking it.
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 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.
Care of young
Young bichirs in this example P.senegalus, As they
breed in captivity and are now being farm raised
and are the most readily available subjuvenile of
the bichirs and the cheapest ( $5-10) range
and they are incerdibly small when we buy them
2''-3'' is about normal .
This is how I raise them certainly there are other
ways. I use the step up system in other words
small fish small tank as it grows I move it up
to bigger tank. Its a three step process I use
they start off in a 10 gallon tank with the water
level reduced to about half the tanks volume
fine gravel or sand for the substrate and silk
plants for cover and to float in.At this stage
they are fed bloodworms and baby brine shrimp
chopped squid and very small silversides
I feed small portions a few times a day.This
isn't possible for many but try feeding morning
and again at night, between now and 7" they
are undergoing their greatest growth and are
hungry constantly
When they reach approx. 5'' i add a small
power filter and raise the water level to approx
2 inches under the trim frame.At this size they are
bigger foods small feeder, ghostshrimp,bloodworms
earthworms etc .They stay in this tank till 7-8'' at which point
I move them to a 20 gallon long for final growout
These steps allow the bichir room to exercise
but still small enough so its easy to find/catch
food. Of course if I get a bigger specime
5-6'' they would go into the 10 gallon then move
up to the 20 long this gives me time to watch
for any signs of illness.
Tank set up
Bichirs are low light loving fish as many are nocturnal and some dinural . The tank
needs a secure top or lid with any opening plugged as some species are escape
artists and others can jump well.The water level needs to be 2-3 inches below normal
as bichirs need to breathe air from time to time. The substrate should be sand or finely
crushed gravel. driftwood with short bushy plants.attached or anchored under it.
In general I find it hard to have live plants as bichirs tend to uproot them searching
for food, floating plants are a good option though ,I silicone silk plants to nylon needlepoint
canvas and bury it in the substrate in one square foot sections makes it easier to
remove to clean and rebury in the substrate. One last point no sharp edges
bichirs tend to move close to things and sharp edges remove slimecoat
Feeding
Live foods : guppies , rosey red minnows, ghost shrimp, earthworms
frozen: bloodworms, mysis shrimp,brine shrimp , krill, squid and frozen silversides
and a good quality pelletized food with the following nutritional values , PROTEIN:: 45% or more (this would be the ideal)
FAT:: 3% Min. to 6% Max.
FIBER 2% Min. to 4% Max
lean meaty foods such as beefheart are good too
but you need to balance their diet for nutrition so vary the diet, not just one
thing.How much to feed them ? Feed them until their belly bows slightly.
and skipping a meal will not hurt them once they are
past 7-8 inches remember in the wild food is not
always available.A nice round bichir is a happy bichir -Anne
