he Ariidae family is
wide spread, ranging throughout the continents of
Asia, Africa, Australasia, South and Central America
and there are about 80 species with the vast amount
of them occurring along sea coastlines, estuaries
and coastal lagoons hence one of the common name of
this genus, Sea Catfishes. Until 2007
this species was known as Arius graeffei but
there has been a name change for the members of the
Ariidae family who reside from Southern New Guinea
and Northern Australia, Arius to Neoarius.
The species we
are concentrating on this month is one of only 5 represented
in the freshwater rivers of Australia and Papua New
Guinea, the 'Lesser Salmon Catfish', Neoarius
Make sure that
you don't let the p.H. drop too low as they like it
more on the alkaline side. They have appeared
periodically in the tanks of retailers and I would
be interested if someone out there is still keeping
this species.One cause for concern is the poisonous
spines of the dorsal and pectoral fins as they will
need to be treated with respect as it can take quite
a while for a wound of this nature to heal up if you
are unlucky enough to be punctured.
not terrifiic in this species as they have a dark
brown to blue upper body fading to a white/creamy
underbelly. They are also treated as a food fish in
its native habitats, they are renowned for their good
taste if prepared properly but some fisherman treat
them as pests as they can get caught in their nets
and can take a considerable amount of time to disentangle
them, and of course as well as avoiding the sharp
spines they can ruin a net for future use.
One very interesting
subject that was thrown up by my enquires was the
homeing device or electrical fields that
this species possesses and below I have reproduced
a published paper from the Australian Defence Science
site from Alan Theobald DSTO Defence and Darryl Whitehead
of the University of Queensland Australia called,
Using Fish Sense for Mine sensing.
sensory capabilities of fish may one day replace conventional
sonar as a means of detecting marine threats such
as sea mines. New research sponsored by DSTO's Maritime
Operations Division at the University of Queensland's
Zoology Department is exploring the electro-reception
used by various fish species for possible military
catfish (Siluriformes) and sharks and rays (elasmobranches)
can detect electrical fields as weak as 0.07 and 0.001
microvolts per centimetre, respectively. Researchers
at the University of Queensland have shown that the
Australian salmon-tailed catfish (Neoarius
graeffei) has a sensitivity equal to or better
than any other bony fish. In fact many indigenous
animals, such as platypus and echidna, can detect
the very low electric fields from their prey.
The new research
program will target species that inhabit estuarine
waters and, indeed, migrate between fresh and salt
water which have vastly different electrical conductivities.
It is hoped that a good understanding of the physical
and biological processes will result from observing
of the same species.
electroreception of its prey by a catfish (Neoarius
(above), for example, shows the changes in heart rate
(top) and blood pressure (bottom) when a voltage of
70 nanovolts is introduced along the sides of the
has a long way to go before military applications
can be realised. However, if it is possible to replicate
the type of natural mechanism plus the signal processing
chain, then an alternative to sonar could be produced.
In the first instance, noting that the ranges at which
fish themselves detect electric fields is of the order
of metres, this work is targeted at the possibility
of detecting mines, which might be buried in the sea
bed and therefore difficult to detect using acoustics.
electro-receptive unit in fishes is the ampullary
organ (shown) which is the ampulla enlarged portion
of the canal containing receptor cells and supportive
cells. Receptor cells are electro-receptive sensory
cells and the cup-like cells that encase them are
the supportive cells.
and structure of the ampullary canals varies greatly
between species and habitats. They can be six centimetres
long on the marine catfish (Plotosus anguillaris),
whilst on freshwater catfish they can be just 0.1
to 0.2 millimetres long. The ampullae themselves may
contain hundreds of sensory cells and species may
have thousands of ampullae over the skin.
only the toothed whales, such as dolphins and porpoises,
have been shown to have evolved active sonar as a
detection mechanism in water. Left : Darryl Whitehead,
University of Queensland with Neoarius
graeffei. Many fish species do, however, detect
water-borne acoustic energy up to a few kilohertz
from sources other than themselves.
marine animals have evolved other sensory systems
such as olfactory, magnetic, electric and tactile,
as well as optical. These systems are used for both
detection of prey and navigation. By contrast, human
technology has developed sonar systems, either passive
or active, primarily to detect underwater objects.
Since World War Two, vast military funding has been
directed at the development of complex sonar systems.
This research represents one step in the search for
complementary approaches to sonar for underwater detection.
Darrryl Whiteheadof the University of
Queensland for his permission to use his paper, Using
Fish Sense for Mine sensing.
Salmon Catfish, Blue Catfish, Salmon Catfish.
from the Houtman Abrolhos Islands, Western Australia
to Hunter River, New South Wales.
Papua New Guinea,
in the Purari River.
50.0cm (18ins) somewhat smaller
20-27c (67-81f )
Dorsal 1/7; Anal 15-19; Pectorals;
1/10 to 1/11; gill rakers on first arch 17 to 22;
raker like processes on back of all gill arches, 12
to 20 on first, 15 to 23 on second, 15 to 21 on third;
palatel teeth villiform, in transverse series of 4
oval patches, inner (vomerine) patches smaller than
outer (palatine) patches, patches may fuse in larger
specimens to form two patches or one large patch across
palate; maxillary barbels moderately long, 2.5 to
5.8 in SL, extending to edge of opercle, usually to
above pectoral fin base or midway along pectoral fin
length or below dorsal fin spine in juveniles; head
ovate, snout rounded or slightly truncate; head 3.0
to 3.8 in SL; eye oval, 3.7 to 8.4 (mean 6.1) in HL.
Dark brown, dark blue, fawn
or ocher above, sometimes iridescent, fading to yellowish,
cream or white ventrally; some fish from western Northern
Territory with black and cream blotches; fins tan
or bluish brown.
Care & Compatibility
Only N. graeffei and
Tachysurus berneyi out of the 5 species
are deemed appropriate for housing in an aquarium
as the rest get way too big for captivity. You would
need a good sized tank of course as N.
graeffei can grow to around 18" and if kept
with other fish would need to be housed with larger
Cichlids for instance, as they can be carnivorous,
but as far as my enquiry's have thrown up they can
be a good addition to a larger tank.
This fish and
some others of its genus have an unusual breeding
pattern for a catfish, it is a mouthbrooder!. The
male incubates the eggs buccally for 2-4 weeks at
at a temperature of 32c. When hatched the young are
relatively large and at 2 months of age they are about
6cm long. The females ventral fins are modified into
claspers to assist in the retaining of
the eggs as they are extruded. The breeding season
in the wild is reported to be the beginning of the
wet season (spring or early summer).
In its native habitat they
feed on insect larvae, aquatic plants, prawns, crayfish,
molluscs and small fish. In the aquarium they will
eat anything given such as earthworms, chopped liver,
frozen brine shrimp, prawns, pellets, tablets and
Neo means "new" in latin and Arius
is Derived from the Greek word Apelos (pronounced
Araios) which means "sanctified by the god of war",
and refers to the bony structure extending from the
skull covering to the powerful thorn of the first dorsal
R.Gerald. Freshwater Fishes of Australia.1989.
Baensch, H.A. and R. Riehl 1991 Aquarien atlas. Bd.
3. Melle: Mergus, Verlag für Natur- und Heimtierkunde,
Germany. 1104 p. Burgess, E.Warren Dr. Atlas of Freshwater &
Marine Catfishes 1989. Ferraris, C.J.Jr. 2007 Checklist
of catfishes, recent and fossil (Osteichthyes: Siluriformes),
and catalogue of siluriform primary types.