Loricariidae: Neotropical catfishes

Loricariidae. The Loricariids are the world's largest family of catfishes. If you're really together, you're calling these catfish "Lories" now, as the late Al Ngui suggested, so that you can reserve "Pleco" specifically for the Ancistrini and Hypostominae groups, the ones that include the traditional Ancistrus and Hypostomus genera of armored cats. There are three more divisions of the Lories, the Hypoptomatinae, which includes Otocinclus and its mini kin, the Loricariinae, or whiptails like Farlowella and Sturisoma, and the Neoplecostominae, which have mostly not been imported.
 
As for "dwarf" Lories, RTR put it succinctly at an Aquarium Central post, Oct. 2000: "There are no real dwarf plecos. But then there are no real plecos either. Plecostomus was a genus of suckermouth catfish (Loricariids), which is no longer a valid name... smaller suckermouths were imported with no known or even identified scientific name and called "Dwarf Plecos" to distinguish them from the "real" plecos, such as Hypostomus plecostomus (the species name is still valid). The dwarfs are quite different fish, from genera such as Peckoltia and the small Panaque species, most being 3-6" at full maturity. There is no dwarfism involved, merely entirely different fish with a family resemblance to their several times larger cousins."
 
When your Lories hang on the glass, take a magnifier to see how they are entirely covered with odontodes, the teeth that are embedded in their skin, which are sometimes thickened to produce spines. Even an Otocinclus is covered with tiny prickles, which will hang him up sometimes in your net.
 
Lignin in the diet. Many Lories rasp at the surfaces of waterlogged wood and depend on wood to supplement their diet. Panaque species are especially noted for this, and some even have spooned chisel-like teeth to help them. Loricariids can be assumed to carry some kinds of co-evolved protozoan and bacterial fauna to digest lignin for them, for no vertebrate can digest lignin. Now Jay A. Nelson at Towson U. is unravelling this specialized feeding niche. His illustrated article,"Respiration in wood-eating catfishes" is the best intro to this story. He finds that the breakdown of lignin in Panaque guts is effected by a consortium of microorganisms. Some insects notorious for eating wood also depend on symbiotic partnerships to break down lignin. Termites are a well-known example, but Cryptocerus wood roaches and passalid bess beetles also make a living chewing splinters of wood and getting the lignin digested for them by intestinal protozoans. Interestingly, all feed their offspring directly from the anus, so that the protozoan community among the wood fibers can colonize the intestines of juvenile insects too. I have a point in mentioning this shared phenomenon. To come back to the aquarium, this suggests a treatment for rehabilitating a half-starved Lory: — give it the company of a plump, well-fed one. In rooting among detritus the two fish are bound to share some beneficial,— perhaps essential— gut protozoa. If they are socially too incompatible, try vacuuming detritus and adding it to the newcomer's tank.
 
Links. Dr Jonathan Armbruster's Loricariid Home Page is the site to scope out if you're curious about any of these Lories. This is one of the best websites devoted to a family of fishes —  scientific but accessible. There's a list of taxa, a key for identification of your Lory, a phylogenetic tree showing how the various genera are related to each other, all by the taxonomist who is the definitive reviser of these catfishes. Loricariid catfishes are also well represented at ScotCat and at Planet Catfish.