t has recently come to my attention
that some cold water aquarists in the British Isles
have an interest in American species, especially catfish.
I find this most interesting, as I grew up in the Mississippi
watershed. That's a rather large area, something like
the size of Europe so I'll be a bit more specific. If
you have a detailed map of the United States you can
trace the Mississippi river down to just below its confluence
with the Ohio river. The next large river down, about
50 miles, flowing in from the east is the Obion. Tracing
it back eastward and northward, you will come to my
hometown, Martin, lying between the north and middle
forks of the Obion river. I spent my childhood and my
early adult years roaming the countryside there and
along the Tennessee river, further east by 70 miles.
In the drainage
area of the Obion river system, consistingof the
North, Middle, South and Rutherford forks in northwest
Tennessee, just 70 miles south of the Ohio river,
the country is largely given over to farming. Most
farmers keep some beef or dairy cattle and so, dig
small ponds to provide water for their stock.
These ponds are usually 3 or 4 feet deep and rarely
more than 50 feet in diameter. They stay muddied
all the time due to the cattle. Almost invariably,
they are populated by Ameiurus natalis and
Lepomis cyanellus, the yellow bullhead and
green sunfish respectively. Locally they are known
as the "mudcat" and "goggle eye".
These two species have proven themselves ideally
suited to the harsh environment that a cattle pond
In the larger tributaries of the Mississippi that
I have explored, the Tennessee, the Obion, and the
Hatchie rivers, A. natalis is comparatively
rare, the dominant catfish being the channel catfish,
Ictalurus punctatus, however, A. natalis
dominates in smaller tributaries and ponds. I can't
say with any certainty why this is so, perhaps because
A. natalis is better able to withstand the
low water and oxygen depletion of the smaller bodies
of water in the summer months. I have many times
seen ponds stocked with I. punctatus suffer
massive die-offs in August, but never a pond with A.
natalis, even when the pond was so over-populated
that the fish were stunted to a mature size of 4
inches long. I have even seen this catfish surviving
from season to season in very shallow ponds that
dry to little more than a puddle in summer.
the stocking of ponds with channel catfish, I.
punctatus, I should explain, that in that area
of America, A. natalis, locally "mudcat",
is considered rather worthless. The mudcat is aptly
named, as it's flesh has a distinctly muddy flavor.
This can also be true of the channel catfish, but
is not normally the case. The mudcat has a
very large head in comparison to the channel catfish,
so it dresses out much lighter than the latter of
the same weight. Many ponds are deliberately stocked
with channel catfish and a hybrid sunfish, Lepomis
cyanellus x Lepomis macrochirus. These
sunfish produce predominantly male offspring and
thus can not overpopulate a pond. If it is discovered
that mudcats have appeared in the pond, it is considered
ruined and drained, since these fish will quickly
take over. Such infestations can be from several
sources; the transfer of fish from pond to pond
by herons, tornados emptying farm ponds and scattering
their contents, including fish, over a wide area,
and small boys who release their catches into new
I was once such a small boy myself, and having caught
three mudcats about 4 inches long from an overcrowded
pond one spring, I released them into a new pond. This
pond leaked and later in the year when the pond
had dried to little more than a puddle, the three
catfish had grown to about one pound each and hundreds
of little catfish were present.
The largest specimen of A. natalis I ever
saw weighed approximately 4 pounds. This was
exceptional, the normal weight is 1 to 2 pounds.
In contrast, I. punctatus regularly goes
4 four pounds, and I have seen specimens from the
Tennessee river weighing in excess of 50 pounds.
While 50 pounds is a rare catch, the channel catfish
weighing in excess of 10 pounds are not.
In its native habitat in the Obion river water shed,
A. natalis survives winters in which the
ponds may be frozen over for as long as a month
and summers in which their ponds may dry down to
as little as one foot of depth and the water temperatures
exceed 90 degrees F.
In farm ponds, A. natalis has a variety of
prey, including Amnicola limnosa, the pond
snail, several species of crayfish, the tadpoles
of several species of frogs and toads, and in some
ponds mussels of a type similar to the Margaritifera
margaritifera common to Europe. Mussel is recognized
as the favorite food of catfish and it is common
to see the stomach and intestine full of mussels
about 1/4 inch in diameter. The catfish swallow
these whole and then pass the shells. A. natalis
is in turn the prey of herons, snapping turtles,
and when the water is low, the raccoon, redtail
hawk and even the turkey vulture.
In the spring of the year, tight masses of A.
natalis fry can sometimes be observed at the
surface of the water. At this point the fry are
1/2 to 1 inch long and they hold tightly together
in a circular mass, touching one another as the
mass moves slowly around the pond. This is usually
observed in March or April when the weather has
warmed into the 70's F and after spring rains. I
would imagine that breeding A. natalis
would be no problem in the British Isles for
anyone with a goldfish pond. (Probably in the south
of the country, Ed. see restrictions)
Releasing the fish into the pond in the autumn,
so that they go through the dormant cold period,
should yield hundreds of fry the following spring.
They would pose little or no threat to goldfish,
other than smaller fancy varieties. I have seen
the two coexist and flourish. One thing I would
point out is that the term 'cold water aquarium'
is a misnomer.
Four months of the year, most of the waters at home
are hotter than tropical, and the water is still
warm enough to swim in up until October. The
daily high temps there just dropped below 80 F last
week ( Beginning of October). The waters of the
larger rivers will run in the 70's for the rest
of the month, maybe well into November, depending
on the rain.
It should be noted that concerns about the release
of this fish into the natural habits of the British
Isles are probably valid, especially for smaller
waters. In the area of the Obion river watershed,
this fish has proven itself capable of dominating
other more desirable catfish species when conditions
Photo Credit: Ameiurus
natalis - Konrad Schmidt.