months factsheet, April 2016, is concentrating on
the Doradidae family or commonly known as the "talking
cats" due to the noise they make when removed
from the water. Confused sometimes with the Auchenipteridae
family (Wood cats) but they possess a row of scutes
along their sides which is characteristic of this
group. Our subject is the "Granulated catfish"
Pterodoras granulosus which is rather on
the plain side but can have some interesting shades
of brown and olive depending on what location they
are captured in and their age. In their natural habitat
they will form small groups and feed mainly on mollusc's
and the fruits/nuts of the palm tree, Astrocaryum
They can sometimes
be identified by their small eyes high on their head
and the forked tail. In common with most of this family
they are nocturnal so hiding places in the aquarium
are essential for their well being. As this is quite
a sizeable "Dorad", a large tank or heated
pond at least 7'0 long with a footprint of at least
4ft. in width so that it can turn round would be beneficial.
This is not a species for your usual community tank
as an adult size of 36ins (90cm) is a veritable lump
- Chris Ralph in Peru 2000
I along with
other U.K. aquarists (see articles)
visited Peru in 2000 and the image above portrays
author and aquarist Chris Ralph with his catchment
of a juvenile
Pterodoras granulosus in
the wild. In specimens collected in the Amazon River
during a period of low water, the stomachs contained
large amounts of plant material and the intestine
corresponded on average 215% of the length standard
(Maple and Sanchez, 2002).
This species was
captured in lagoons from overflowing and to the main
channel of the Amazon River. They can survive for
hours out of water provided that their skin stays
wet. Is is also very common to find them alive in
the local markets.
and Paraná River basins and coastal drainages
in Guyana and Surinam.
Head is wider than long. They
have 3 pairs of barbels and posess small eyes. The
humeral process is relatively short. 25 to 30 scutes
adorn its sides. The adipose fin extends and forms
a keel. The caudal fin is strongly forked.
The colouration of the body
varies with age. Juveniles are brown clear, with lots
of dark spots of the size of the eye and distributed
irregularly throughout the body and fins. Adults lose
this dot pattern and acquire a uniform tone green
Care & Compatibility
As with most "Dorads"
they are quite adaptive to water parameters but there
is a question mark on p.H. values above 7.5 as there
are reports (Baensch, H.A. and R. Riehl, 1985) that
this high p.H. can cause eye and skin cloudiness.
Provide hiding places such as pipes large enough for
these large "Dorads" to squeeze into and
a tank with subdued lighting. Can be housed with large
cichlids, catfish and larger characins. Peaceful catfish
for its size but could mistake smaller species as
food on its night time forays.
Not known but
presumably the female would have a wider girth.
In nature they feed on snails,
water plants and fruits. The usual aquarium fare will
suffice. Trying different fruits would be a good project
for this species.
fin: Fleshy finlike
projection without rays, behind the rayed dorsal fin. Barbels: Whisker-like
structure on the heads of most catfish.
Caudall fin: The tail. Humeral process: Bony extension of
the pectoral girdle. Nocturnal:Active
at night. Scutes:Bony covering.
Pterodoras:Greek, pteron = wing, fin + Greek, doras
= skin. granulosus:
Named after the nature
of skin with granules.
H.A. and R. Riehl,
1985. Aquarien atlas. Band 2. Mergus, Verlag für
Natur-und Heimtierkunde GmbH, Melle, Germany. 1216
p. Conservación Internacional;
seris de Guías Tropicales De Campo. Pecos del
medio Amazonas Región de Leticia. 546 p.