Orcés V. 1962
The month of August 2012 welcomes back
again the eminent catfish author and enthusiast, Steven Grant,
to investigate for
us another species,
this time from the Aspredinidae family otherwise known as the
"Banjo catfishes". His subject is a little known species
from the upper Amazon and Orinoco River basins, the Shark Banjo
catfish, Xyliphius lepturus.
he subject of this factsheet is a rarely encountered Banjo Catfish.
Whereas Bunocephalus species can be found in most aquarium
shops, I have only ever seen this species once, and another member
of the genus, once. So, if this species is rarely available one
could ask why bother providing a factsheet? Firstly, I think this
species helps to break the commonly held view that all Banjo Catfish
are sluggish fish, and also I don’t want anyone to make
the same mistake I did, should they be fortunate enough to purchase
this species (or any Xyliphius).
Xyliphius Eigenman 1912 (Eigenmann
used two spellings in the original description; Xiliphius
being the other, but the former is the one used).
Xyliphius currently has 7 valid
described species (Figueiredo & Britto, 2010), the majority
of which are found in northern South America, with 2 being found
in middle to southern South America. There are few specimens in
museum collections and few find their way into the aquarium hobby
(more on this later). The easiest way for aquarists to identify
a Xyliphius is the combination of a tiny eye (very difficult
to spot on some species), the triangular head/snout, and the numerous
fleshy papillae projecting off the lower lip.
Xyliphius lepturus Orcés
The only time I encountered this species
was approximately 2005 at a now defunct shop in West Yorkshire.
I had never seen a Xyliphius in the flesh before but
had an idea based on a photo I had seen on the Internet. The price
was comparatively high for a banjo catfish so I could only take
The fish was put in an aquarium with a
sand base and an internal power filter. It was housed with Corydoras
and loricariids. It buried in the sand during the day, with just
its mouth showing. After lights out I used to watch the tank with
a dim light. It would never touch dry food and would only eat
livefoods. I noticed that when moving it did so in darting, jerky,
side-to-side movements, as opposed to the slower, forward, shorter
propulsion methods of Bunocephalus species. Although
it was eating, and showed no signs of disease, it died after about
When researching for information on Banjo
Cats I came across the descriptions of all Xyliphius.
Taphorn & Lilyestrom (1983) state that Xyliphius
“live in the sand at the bottom of the turbulent rivers
and strong currents, in total darkness.” Figueiredo &
Britto (2010) state that their new species was “captured
by day in shallow waters. Due to its diminished eyes and rough
skin somewhat free from underlying muscles, together with its
extreme rarity in collections, we speculate that Xyliphius
anachoretes is a cryptic fossorial species.” So it
is clear that Xyliphius live in moderate to turbulent
water, hiding in the sand by day, and feeding at night. I think
that had I provided a stronger water current in the tank, my specimen
would have lived much longer. Therefore, anyone lucky enough to
obtain any Xyliphius should provide a moderate to strong
current over the sand substrate, with plenty of live or frozen
Dorsal fin 1/5; Anal fin 9; Pectoral fin
1/5. Head depressed, profile of cranium slightly rises to dorsal
fin. Eyes very small. Body after dorsal fin slightly depressed and
elongated. Strong pectoral fin spines. Skin on head with tubercles,
which on the post dorsal area of the body are arranged into lines.
Base colour is greyish white, with the
upper head and back dark grey or bluish. Upper surface of pectoral
fins, base of dorsal fin, and midlateral anterior portion of caudal
fin dark grey or black.
An extremely peaceful and lethargic species.
May eat fry but other than that will not harm other fish. Should
be kept with peaceful tankmates.
As yet unknown.
There are no proven
external sexual differences.
Frozen or live bloodworm, live tubifex
derived from the Greek word, xylephion = a little piece
of wood (referring to the woodlike appearance of the type
species of the genus)
from the Greek word leptos = thin, and the Greek suffix
-ouros (which is derived from the Greek word oura = tail)
C. A. and M. R. Britto, 2010. A new species of
Xyliphius, a rarely sampled banjo catfish (Siluriformes:
Aspridinidae) from the rio Tocantins-Araguaia system. Neotropical
Ichthyology v. 8 (no. 1): 105-112.
Mees, G. F., 1988. The genera of the subfamily
Bunocephalinae (Pisces, Nematognathi, Aspredinidae). Proc.
K. Ned. Akad. Wet. (Ser. C Biol. Med. Sci.) v. 91 (no. 1):
Orcés V., G.,
1962. Dos nuevos peces del género Xyliphius. Ciencia
y Naturaleza (Quito) v. 5 (no. 2): 50-54, 1 pl. [English
Reis, R. E., S. O. Kullander
and C. J. Ferraris, Jr., 2003. Check list of the
freshwater fishes of South and Central America. i-xi + 1-729.
Taphorn, D. C. and C. G.
Lilyestrom, 1983. Un nuevo pez del genero Xiliphius
(Aspredinidae) de Venezuela.
Revista Unellez de Ciencia y Tecnologia v. 1 (no. 1): 43-44,
The fin forward from
the anal cavity.
Caudal fin: The tail.
Pectoral fin: The paired fins after head
and before anal fin.
Dorsal fin: The primary rayed fin(s) on
top of the body.
© Steven Grant