his month we stay on the North American
continent and go on to a very large catfish from the Ictaluridae
family and in a genus all of its own, Pylodictus olivaris.
This large cat could be said to be somewhat placed between the
genera of Ictalurus and Ameiurus in its appearance
and can be found in southern Canada, United States and northern
As can been seen in the above picture (and
its mouth!) this is not a catfish for the home aquarium and can
only be housed when large in a public aquarium facility. They
are solitary creatures and inhabit large creeks, rivers and reservoirs,
near the cover of rocks, logs or other debris. When young they
tend to often live among rocks in a slight current. They are mainly
a sport and food fish and specimens of 14-23 kg (30-50 lbs) are
not unheard off.
The range of Pylodictus olivaris is SE. Ontario, West
Pennslvania, SW. Wisconsin, north Dakota, south to Texas and NE.
Mexico; east in Gulf drainages to the Mobile Bay drainage of Alabama,
In these pictures it certainly looks a fearsome looking beast
and when adult it is piscivorous (fish-eating) but when they are
young they are predated on by Bullheads and Channel Catfish but
soon mature to feed on aquatic insects, crayfish, small fish,
worms and then on to the larger fish when adult. The picture below
shows a young juvenile of Pylodictus olivaris showing
a more mottled and colourful pattern. In common with a lot of
large catfish that lose there juvenile markings to become in later
life, a more subdued pigmentation. Sexual maturity is not reached
until 3-4 years and is said to have a life expectancy of 20 years.
Spotting the difference between the genus
Pylodictus, Ameiurus and Ictalurus
is not too hard. The caudal and anal fin shapes in the table below
show the differences and also the lower jaw of Pylodictus
protrudes while the jaws of Ameiurus and Ictalurus
do not. The body shape of Pylodictus is also flatter
than the other two genera.
anal and caudal fin
Bullheads, anal and caudal fin
Channel cats, anal and caudal fin
The shapes of the anal fins are
quite distinct with Pylodictis being more rounded than
the bullheads and the channel cat has more of a keel shape.
Acknowledgements: Garold W.Sneegas
for the use of his photographs.
for providing information on this species.
Head large, wide and very flat. Eyes small;
mouth wide, lower jaw projecting beyond upper. 4 pairs short barbels.
Adipose fin large; dorsal fin spine weak; 14-17 anal fin rays;
caudal fin truncate, weakly notched.
Sides olive-yellow to light brown with dark
mottling; belly yellowish; caudal fin dark brown to black, with
upper lobe unpigmented. Other fins yellowish to light brown.
This is not a catfish for the home aquarium
and can only be housed when large in a public aquarium facility.
They first spawn at about 4-5 years old
in June and July when water temperatures reach 22-23° C (72-75°
F). The flathead, normally a loner fish, pairs up with one of
the opposite sex and both the male and female construct the nest.
They dig out a large hole under a bank or log or dig down through
silt and mud until they reach gravel. They spawn in the nest with
the female laying eggs in bunches of 30 to 50. A single female
can lay 3,000-30,000 eggs depending on her size. When the female
is done, she leaves the nest. The male fans the eggs with his
fins. After they hatch, he protects the young until they can feed
on their own.
Juveniles feed on aquatic insects, then
on to crayfish small fish, worms and larger fish when growing
Greek, pylos = mud + Greek, ichthys = fish
olivaris: Means "olive-coloured"
Top two: © Garold W.Sneegas
The Audubon Society Field guide to North America Fishes,
Whales & Dolphins, 1986.
Smith W.Philip; The Fishes of Illinois,
University of Illinois Press. 2002.
Bottom: © Konrad P. Schmidt
|Silurus olivaris, Hopladelus
olivaris, Pelodichthys olivaris, Leptops olivaris, Opladelus
lower Great Lakes and Mississippi River basins from western
Pennsylvania to White-Little Missouri River system in North
Dakota, and south to Louisiana in the USA; Gulf Slope from
Mobile Bay drainage in Georgia and Alabama, USA to Mexico.
Transplanted elsewhere in USA
| 155cm. (5ft-2ins)
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