his
month we are concentrating on a small member of the
Auchenipteridae family, the "Driftwood
Cats", and also the small genus Trachelyichthys
which comprises of only two individuals, this months
choice and also T.
decaradiatus. To put
you in the picture, the genus Trachelyichthys was
created in 1974 by Dr.Mees and in his paper there
was only a single specie, Trachelyichthys decaradiatus
from the Rupununi River, British Guiana and so T.exilis
didn't come along until 1977 where it was described
from the Rio Mamon, Peru which is basically on the
other side of the South American continent approximately
1,800km away from the first genus discovered. The
specimen was caught in a shallow part of the river
approximately one metre (39") deep. The substrate
consisted of mud and sand. The water was acidic and
the surface temperature, 28°c (82°f).
Trachelyichthys
exilis
To
differentiate between T. exilis and T. decaradiates
is sometimes not that easy as they both have the same
basic body colouration but the main difference lies
in the shape of the humeral process and the positioning
of the eyes. Below you can what I mean from the published
papers of Greenfield & Glodek, 1977.
In the image below
you can see the positioning of the eye in T. exilis.
The next image
below shows T. decaradiates with the rounded
humeral process.
Trachelyichthys
decaradiates
Telling the boys
from the girlsisnot too hard in mature
specimens as the maleshows an extension to
the front of its anal fin as is the norm in this family
and the female has a normal fin. Below you can see
the difference in sexing the genus Tatia which
is in the same family. The only difference is the
length of the anal fin in T. exils and T.
decaradiatus but it does give you an idea and
should help you sex out this species if buying from
an aquatic outlet.
So basically a goodcatfish
all round if a little secretive, they don't particular
like to be on their own so have at least a pair
or better still a small group of them, and you may
have a little luck and spawn them.
Common
Name
Pigmy
Driftwood
Synonyms
None
Family
Auchenipteridae
Subfamily
Auchenipterinae
Distribution
South America:
Peru, Nanay
River basin in upper Amazon River drainage. Type
locality: Río Mamón, a tributary
of Río Nanay, approximately 25 km west of Iquitos,
3º42'S, 73º16'W, Peru.
Size
9.5cm (3¾ins)
Temp.
22-25c (71-77f)
p.H.
6.5-7.0.
Characteristics
Small
based dorsal. Large eyes well forward on head. Long
pointed humeral process.
Colouration
Silver
tone with black band running over top of body interupted
with some spots. Lateral line with large black spots,
rest of body with varius spotted pattern. Dorsal spine
with black stripe with rest of fins spotted.
Aquarium
Care & Compatibility
Keeping both species is not
too much of a problem as long as the water is kept
clean and not too alkaline with a p.H.of between 6.5
and 7.0. They do like a planted aquarium where they
like to hide during the day. They also make a good
show fish if showing your fish at shows is your forte,
as they usually deport well in a show tank.
Reproduction
This is a piece
taken from the Baench Aquarium Atlas 3 on the breeding
of this species: "Well-fed fishes have been known
to spawn in aquaria. The male embraces the female
so that his genital papilla is very close to the anus
of the female. Eggs are fertilised before they are
laid among plants; Java moss makes an appropriate
spawning substrate" A few members of the Auchenipteridae
family have been spawned in the hobby with a successful
breeding and raising of the young of Trachelyichthys
exilis by Dick Thompson, a former member of The
Northern Area Catfish Group (now
Catfish
Study Group).
Sexual
Differences
Mature
specimens, as the maleshows an extension to
the front of its anal fin as is the norm in this family
and the female has a normal fin.
Diet
In the aquarium a good mixture
of dry food such as flake and tablet. Worm food such
as bloodworm, whiteworm and grindal will keep the
'pygmy driftwood' happy in its suroundings.
Etymology
Trachelyichthys:From
the Greek, trachelos, meaning neck, pteron, meaning
fin and ichthys, meaning fish. exilis:Slim or
slender, pertaining to the slim humeral process.
References
Baensch,
H.A. and R. Riehl 1991
Aquarien atlas. Bd. 3. Melle: Mergus, Verlag für
Natur- und Heimtierkunde, Germany. 1104 p. Greenfield, D.W. &
Glodek, G.S.1977:Trachelyichthys
exilis, a new Species of Catfish from Peru.
Sandford, Mike; CAGB Magazine
41 1984 : Trachelyichthys - two of a kind.
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