I don't feed mine any live food. But lotus that is the one I bought. The one I have is a bit lighter....Beige in color.
Pet store said it could grow up to 2.5" Just realized my ex nabbed my digicam...will be a while before I can add my tank to the gallery.

well maybe its a different type than in the petstore I saw...or your lfs was wrong :)

Tonguefish
 

Hello, Mantis ... how's the tonguefish doing? I, too, couldn't resist the novelty of the thing and bought one (1.75") for my 55 gallon ... something I seldom do without first checking out it's full requirements(!), but knowledge of these fish seem to be all-around minimal at best. But he's been in there for over a week, making his way into an established community pretty much dominated by a full-grown Leporinus.

Is yours still alive and, if so, what have you been feeding him? (I've never really seen mine while feeding, though assume he's getting into the brine shrimp ...)

Mine has a white underside, grey-brown top with black spots; I have not yet been able to identify it's species. According to the store stats, he should grow to around 8".

Sadly it died w/in a month or two after I brought it home. If I saw it again I wouldn't hesitate to buy it though.

Tonguefish - Cont.
 

I'm sorry to hear that ... it's really one of the coolest fish I've ever seen; definitely a minature relative of the flounder, if not a halibut.

For other tongue fish owners following up on this dialogue (& following up on Lotus' www.fishbase.org suggestion!), the diet appears to consist of:

benthic ('sea bottom') invertebrates and/or crustaceans -- copepods/ostracods (which I interpret as 'brine shrimp'; amphipods (a.k.a. 'water fleas'); polychaetes ('worms') ... all of which should be available in the frozen section of your local fish store; will keep u posted if I have any success.

I also now put in a defrosted cube of beef heart daily which is devoured immediately by the leporinus, the brown knife fish and synodontis; I've also found that an occasional garden slug or earthworm will create the same 'feeding frenzy' for all of these carnivores ... maybe the tonguefish will soon join in .... (?).

Tonguefish - Cont.
 

Here's a better photo of a tonguefish (Cynoglossidae):