Frogmouth Catfish (Chaca sp.)

If you remove a Frogmouth Catfish from its watery home, you might soon hear a peculiar sound fill the air. CHACA... CHACA... CHACA... CHACA... CHACA... CHACA... CHACA... CHACA...

This is where the scientific name comes from for this small genus of 4 South Asian species. They are classified in their own family, Chacidae, and they bear a striking resemblance to the South American banjo catfishes in the distantly related family Aspredinidae. Both groups have a highly flattened body and an enormous mouth for gulping down prey, but the similarities end there.

Their true origins, as revealed in a 2018 molecular study, can be found among a group of catfishes endemic to Asia known as the Sisoroidea. Here we find familiar (or maybe not so familiar) aquarium species like the Asian Bumblebee Catfish (Akysis) and the Moth or Anchor Catfish (Erethistes). An especially noteworthy relative is the infamous Goonch (Bagarius), which can reach sizes approaching 6 feet and was featured in an episode of River Monsters, owing to reports of its potentially feeding upon villagers along Indian streams.

But fear not, Chaca is a much smaller beast, reaching just 8 inches in length, and poses little danger to mankind. Of course, this is plenty big enough to feast upon a wide variety of tankmates, and, for this reason, it is often best to avoid housing it with other fishes. Aside from the danger posed to smaller species, Chaca is also a danger to itself, all too often having eyes bigger than its stomach. It’s not uncommon for this highly predatory catfish to misjudge its prey and wind up with a fatally bloated belly.

Feeding captive specimens is part of the joy of owning a fish like this. Chaca can often be very picky initially, accepting only live foods. But persistence will usually result in frozen foods being accepted. A silverside, wiggled before the mouth, is often quite enticing. One interesting quirk in this group is the reported behavior of them wiggling their nasal barbels to attract prey, giving rise to its other common name, the angler catfishes.

Of the four recognized species, one is restricted to the Ganges & Brahmaputra Rivers of India (C. chaca), one is found in Myanmar (C. burmensis), one occurs on Southern Borneo (C. serica), and the last is native to Peninsular Malaysia, Sumatra, and Northern Borneo (C. bankanensis). It is these latter two which are reputed to lure their prey, as the former lack the nasal barbel. The name Chaca chaca was formerly applied to all of these, and it still is used indiscriminately within the aquarium trade. Correct identification requires knowledge of a specimen’s origins and a close examination of its barbels and papillae.

In their native habitat and in aquariums, these catfishes like to bury into soft sediments like sand and silt. Fisherman are naturally wary of these cryptic fishes, as their sharp dorsal spines are indeed venomous—a relatively recent discovery by scientists is the presence of paired anterior glands associated with the fin spine. But only the most foolish of aquarists is in any danger of being poked by this reclusive creature.