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 V. 1962

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 one.

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 4 weeks.

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 food.

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.

Frozen or live bloodworm, live tubifex worm.

© Steven Grant