Heteropneustes fossilis (Bloch)
or our first factsheet of 2004
we spotlight on a species that could be deemed as one
of the most dangerous freshwater catfish kept by aquarists.
So as not to alarm unsuspecting keepers of this animal, the
dangerous bit concerns the poison that can emanate from a gland
on the pectoral fin spine and has been known to be fatal to
some humans. If stung you should immerse the wound in very hot
water so as to dissipate the poison and then get in touch with
your local doctor.
Now that we have scared the living daylights
out of you :-) we shall commence with a few facts on the Asian
Stinging Catfish. This catfish for many years was in its own
family, Heteropneustidae, and it is only very recently that
it has been moved into the Clariidae family (Diogo, R., M. Chardon
& P. Vandewalle, 2003) which many in the scientific community
thought that is where it should be. There are differences between
the two families listed below. This does mean now that the family
Heteropneustidae is now invalid and is such retired.
Heteropneustidae: Short dorsal fin, two elongate
pulmary sacs that run backwards from the gill through the muscles
in the back.
Clariidae: Dorsal fin, large with many rays. Possess
a much reduced air-bladder and their gills are stiffened to
prevent their collapse when out of water and in a special part
of the gill chamber are spongy arborecent (tree-like) organs
growing from the upper ends of the gill arches.
Heteropneustes fossilis has the same attributes
as the many Clariid species in that it can leave its chosen
home and cross overland to an other body of standing water.
This is helped by its body mucus which helps it from drying
Depending on whose thoughts that
you attain to, there is one other species in this family, Heteropneustes
microps. The reason that I mention this is there is
another theory that microps is a junior synonym of
fossilis and they are one and the same fish. The for
fraternity state that the difference is that H.fossilis
has a separation (notch) between the caudal and anal fin and
that H.microps has these two fins joined together.
The against faction say that the the fusion
of these two fins can be caused by injury and therefore are
one and the same species (Rohan Pethiyagoda and Mohomed M. Bahir
|Line drawing of Heteropneustes
fossilis above showing the notch
between the anal and caudal fins.
Image of Heteropneustes microps left
with fusion of the anal and caudal fins
All in all, not your usual catfish for the beginning hobbyist
but something unusual for the experienced catfish keepers amongst
us, and also a good challange for a breeding project. Give them
Body elongate, compressed. Abdomen rounded.
Four pairs of barbels, one pair = maxillary; one pair = nasal;
two pair = mandibular. Rayed fin short with 6-7 rays. Anal fin
long with 60-79 rays. Ventral fins 6 rays. Two elongate pulmary
sacs that run backwards from the gill through the muscles in the
Uniform grey-brown to olive-brown. Two narrow,
pale to yellowish, longitudinal bands and numerous black spots
on the flanks. Fins often fawn. Anal fin occasionally with dark
marbling. Eye yellow.
Apart from giving it the utmost respect
when handling, it does very well in a larger aquarium, and you
can either keep it alone with other inhabitants that are too big
for its mouth ( large Barbs, Cichlids etc.) or in a group situation
if you would like the challenge of breeding them. A sand substrate
is best with hiding places of rock and cavework and making sure
that it has plenty of swimming space, as they do like to cruise
the tank during the nightime hours. Keep your regular water changes
up with good filtration as they are a greedy species, and can
make a mess of your aquarium if good husbandry is not adhered
Has been reportedly bred in the aquarium
where they excavate a nest in the substrate and the parents look
after and defend the eggs. The young when born are guarded throughout
their early development and can be fed Brine shrimp naupli and
|The females are stockier
looking than the males.
Will eat almost anything such as tablet
and pellet foods. Will also much appreciate some live foods such
as garden worms and other wormlike food. Frozen bloodworm is another
good bet. Experiment with feeding to find the right balance.
from the Greek heteros
meaning other; Greek, pneo = to breath
First & second picture: ©
Rohan and Bahir,
M. Mohomed; Heteropneustes microps, a
junior synonym of H. fossilis (Osteichthyes: Heteropneustidae)
1998. Wildlife Heritage Trust of Sri Lanka.
Jayaram, K.C. The Freshwater Fishes of
India. Zoological Survey Of India, Calcutta.
Burgess, W.E., 1989. An Atlas of Freshwater
and Marine Catfishes: a preliminary survey of the Siluriformes.
T.F.H. Publications, Neptune City, New Jersey.
Diogo, R., M. Chardon & P. Vandewalle,
2003. Osteology and myology of the cephalic region and pectoral
girdle of Heteropneustes fossilis (Teleostei: Siluriformes),
with comments on the phylogenetic relationships between
Heteropneustes and the clariid catfishes. Animal
Biology, 53: 379-396.
Bottom picture: Sridhar Sivasubbu from image
Line Drawing: ( After Misra, K.S. 1962, text-fig.