Some quotes from R.D.'s link for those lazy to read the entire article...
http://german.bio.uci.edu/images/PDF/German (2009) JCPb_gut_print.pdf
The data gathered in this study clearly support the null hypothesis that the “xylivorous” loricariid catfishes do not efficiently digest the fibrous components of wood in their GI tracts.
In conclusion, the wood-eating catfishes in the family Loricariidae appear to be detritivores more so than true xylivores. They display none of the anatomical adaptations other xylivorous animals possess for the harboring of endosymbionts, and their digestive tracts are similar in shape and size to closely related detritivorous fishes.
However, the wood-eating catfishes do take macroscopic detritus (i.e., woody debris) and reduce it to <1 mm in diameter, which likely has signiffcant consequences for carbon cycling in their environment.
Wild-caught Pt. disjunctivus, and P. nigrolineatus obtained via the aquarium trade, poorly digested wood cellulose (<33% digestibility) in laboratory feeding trials, lost weight when consuming wood
.....suggesting that the wood-eating catfishes are not true xylivores such as beavers and termites, but rather, are detritivores like so many other Wshes from the family Loricariidae.
http://german.bio.uci.edu/images/PDF/German (2009) JCPb_gut_print.pdf
The data gathered in this study clearly support the null hypothesis that the “xylivorous” loricariid catfishes do not efficiently digest the fibrous components of wood in their GI tracts.
In conclusion, the wood-eating catfishes in the family Loricariidae appear to be detritivores more so than true xylivores. They display none of the anatomical adaptations other xylivorous animals possess for the harboring of endosymbionts, and their digestive tracts are similar in shape and size to closely related detritivorous fishes.
However, the wood-eating catfishes do take macroscopic detritus (i.e., woody debris) and reduce it to <1 mm in diameter, which likely has signiffcant consequences for carbon cycling in their environment.
Wild-caught Pt. disjunctivus, and P. nigrolineatus obtained via the aquarium trade, poorly digested wood cellulose (<33% digestibility) in laboratory feeding trials, lost weight when consuming wood
.....suggesting that the wood-eating catfishes are not true xylivores such as beavers and termites, but rather, are detritivores like so many other Wshes from the family Loricariidae.