Though not as speciose as the South American catfish families Loricariidae and Pimelodidae, Bagrid catfishes have definitely got the spread (Asia and Africa, including Japan and Borneo) and width (some 30 genera, 210 species) to match these groups of siluriiforms. Most are small, but there are a few giants here (Chrysichthys grandis of Lake Tanganyika attains a length of 2 meters). Physical characteristics are variable but most bagrids have four pair of well-developed barbels and adipose fins of variable size. These are scale-less fishes that nonetheless have formidable protection from predators (and hobbyist hands and nets!) in the way of a stout spine in front of their dorsal and pectoral fins. For brackish aquarium fans, there are a few Asian bagrids that travel in and out of more saline waters.
Of these many species, there are a but a few Bagrid species that make it into the ornamental trade, and those handful mainly from Southeast Asia. This is a great shame as some very unusual to unique species hail from elsewhere, particularly Africa.
Some species of bagrids bear superficial similarities to pimelodid catfishes... can be told apart by the presence of four versus three pairs of barbels on their faces, as well as area of origin of course.
Tanks: As large as possible. Even smaller Bagrid species can "rev up" and move about quickly, and due to their high volume eating it's best to provide dilution volume for wastes. The non-gargantuan species prefer darkened settings with rocks, plants and wood to hide amongst. Very large species should be kept in systems with larger gravel substrates, large rock (if any) and plastic plants (if any), as these will be uprooted and tossed about.
Smaller fishes, able to be taken into Bagrid cat mouths, may well be. Larger, faster tankmates, particularly ones that occur in the same waters are encouraged. Gouramis, larger barbs and rasboras, the freshwater minnow-sharks for the Asian bagrids for instance. African characoids, more peaceful African cichlids for the African bagrids...
Some of the Bagrid cats are quite social and known to school in largish shoals in the wild. Other species like the various Lancer cats are best kept one to a tank, as they can be quite territorial. In fact, even some of the smaller Bumblebee cats can become quite "mean" toward other fishes and should be watched for signs of inter- and intra- aggressive behavior... likely linked with reproductive stage.
Species That Hobbyists Are Likely To See:
In the wild Bagrid catfishes feed on an assortment of aquatic crustaceans, insect larvae, worms of all sorts, algae and vascular plant material. In captivity they are not shy eaters, though recently collected specimens may need to be trained to be fed by light of day, as they are more nocturnal in their feeding habits.
A few of the several Bagrid cats used as food have been bred and cultured for such on fish farms, principally through hormone manipulation. Aquarium breeding is problematic in that territorial males often have larger than their tanks. Parental care is variable, from none to mouth brooding by both parents as in Pyllonemus typus. In the wild, spawning is seasonal with temperature and precipitation changes triggering reproduction. Some hobbyists have had success by manipulating these variables in captive settings.
Many bagrids can be sexed by the males possession of a genital papilla, just in front of the anal fin/urogenital opening, and the males longer barbels.
Catfishes on the Internet: http://phylogeny.arizona.edu/tree/eukaryotes/animals/chordata/actinopterygii/siluriformes/siluriformes.html
Planet Catfish: http://www.planetcatfish.com/core/index.htm
Burgess, Warren E. 1989. An Atlas of Freshwater and Marine Catfishes. Tropical Fish Hobbyist Publications. NJ, USA. pp. 786.
Finley, Lee. 1982. The Asian redtail catfish. FAMA 6/82.
Finley, Lee. 1982. Lophiobagrus cyclurus (Worthington & Ricardo) a Lake Tanganyikan dwarf Bagrid catfish. FAMA 10/82.
Finley, Lee. 1983. Bagrichthys hypselopterus (Bleeker). The black lancer catfish. FAMA 7/83.
Finley, Lee. 1985. Phyllonemus typus Boulenger, an interesting Bagrid catfish from Lake Tanganyika. FAMA4/85.
Finley, Lee. 1997. Amarginops ornatus: a favorite frequently mistaken. TFH 2/97.
Finley, Lee. 1997. Chrysichthys ornatus- Boulenger. FAMA 7/82.
Howe, Jeffrey C. 1998. Original Descriptions: Hemibagrus gracilis Ng & Ng 1995.
Kenney, William R. 1985. Bumblebee catfishes. FAMA 8/85.
Linder, R. Shane. 1999. Unraveling the mysteries of the black lancer. FAMA 12/99.
Nelson, Joseph. 1994. Fishes of the World, 3d ed. John Wiley & Sons, the World. pp.600.
Tavares, Iggy. 1998. Tanganyikan giraffes in your tank. TFH 6/98.
Taylor, Edward C. Bagrid catfishes- a mixed bag. TFH 7 & 10/83.
Thurston, Kevin. 2002. Bagrid catfishes of Asia. TFH 10/92.
Walker, Braz. 1975. The tawny dragon catfish, Pseudobagrus fulvidraco. TFH 9/75.
Walker, Braz. 1981. Parauchenoglanis guttatus. TFH 4/81.
Walker, Braz. 1989. Mystus vittatus. TFH 4/89.