Would have to say that these are a very doclie fish, not bothering anything else in the aquarium, including my multitudes of cherry shrimp. I have two currently, one male and one female, and they spend countless hours exploring everything in the tank, with each other. I will say, that the male , seems to despise the roundtail beta i have in the tank, and will go after his fins when he is not looking (however vice versa is also the same, the beta holds a grudge). The female however does not harm anything, except for REAL little snails. I have seen the female watch some baby cherry shrimp, but didnt bother to snack, just watched them for couple minutes before wondering off... Originally i did have 6, but four seemed to get emaciated and die after about 3 months, and after reading other comments it may have been because of the lack of snails at the time (mainly because of them).
There seems to be some confusion between these guys, which are teensy tiny Amazonian species, and the figure 8 or green spotted puffers which are much bigger and brackish. They couldn't be more dissimilar in my opinion. These guys hardly get much bigger than a jelly bean and have only been guilty in my tanks of a little curiosity every now and again. I have a trio in a heavily planted 15" cube with a gold ram, some ottos, and several amano shrimp. No problems whatsoever. Been like that for over a year now. Extremely interesting behavior. Like most puffers, they seem to really pay attention to what's going on outside of the tank and move each eye independently (like a chameleon) as they watch you. Very neat fish. Oh, and PetSmart gets their fish from the same places as all other pet stores and I doubt very much that anyone is breeding this fish in any numbers to satisfy the trade. That the aggression has been "bred out of them" is silly. There was no aggression in these fish to start with.
A correction: [i]travancoricus[/i] puffers are native to India, not the Amazon. The Amazon puffer is [url=http://web.mit.edu/lovell/www/aquaria/puffer/][i]Colomesus asellus[/i][/url], and it is indeed a purely freshwater fish. However, it is quite a bit bigger than the Dwarf Puffer here.
In my experience the hungrier they are the more aggresive and nippy they get. I kept my two well-fed on frozen Hikari bloodworms and they left every one else alone for almost a year, even a male Betta I had in the tank for a little while (and he had long red "wormy-like" fins). If I went 1-2 days without feeding them they began to nip on everyone.
Well I see a lot of people on the same side as me about these guys. My 4 couldn't be friendlier. ive been told time and time again that they need to be kept alone. Right now mine are with about 6 tetras, 2 apisto cichlids, 1bamboo shrimp, a few ghost shrimp, rubber lip pleco and a red whip plec and i havent seen any aggressiveness? maybe i just got lucky?
Love these guys. I have one male and one female in my 20H tank with 8 Tiger Barbs, 3 Khulis, a Cory and a couple Amano shrimp and everyone gets along great. Their little self articulating eyes are hysterical and they are very aware of whats going on outside, often coming up to the glass to great me.
I love my little female. However, these guys need SPECIAL care, and they are not always suited for the average community tank. Research carefully! PM me if you want to know about them; I can link you to my article on this species.
I originally bought three of these Dwarf Indian Puffers to control snails in my small (6 gallon) tank. The snails ended up being too big for them (most of the snails, anyway) and I lost one about three days after I put them into my tank, even though my water parameters were perfectly acceptable. Now that the snails are gone, I feed them New Life Spectrum Small Fish Formula (.5mm pellets), which they seem to prefer to flake food. These fish are superb for a small community tank; they are too small to be overly aggressive, fun to look at, have quirky little 'personalities', and do not appear to be appetizing to any of their tank-mates. I would highly recommend these Dwarf Puffers to any aquarist who has snail problems, provided that they are introduced to the tank before the snails are too big or there are too many of them. It has been said before here, but it is worth saying again; these are not to be confused with the Figure-8 Puffer or any other brackish water puffer, which are often aggressive while these tiny fish are docile.
Not a few hours passed from the time I posted to this fish profile before I discovered my puffers harassing a Dojo Loach that was six times their size. The harassment got so bad over two days that I had to actually remove the loach from the tank and put it in my larger community tank. (I was going to do this anyway next weekend...)
I've had a few of these over the years. They seem to have more varied "personalities" then any other fish. I had a pair, but in separate tanks for about two years. They never showed any aggression, but they did very effectively remove all the snails of any species, including some large nerite snails and apple snails. They figured out how to flip them over and then eat them out of the shell. One lived in a terrarium and would even pull the legs off of crickets that fell into the water. They are almost too smart. The one I have now lives in a 2.5 gallon with a female betta. The betta occasionally chases the puffer, but usually only momentarily. There are lots of hiding places. It is vicious to the snails still, and will eat any snail almost as soon as I put them in. It has also figured out how to flip them over. Unlike the two I had, this one is very aggressive, and killed 2 corys in a 20 gal I had it in before. Strangely it doesn't seem to be capable of chasing the betta.
I had one of these awesome little guys for some months. At first i kept him in a very large glass jar(jarred pea, it was punny to me...) then a 10x20inch. but, he decided after a while that he would only eat live shrimp and began to refuse prepared and frozen foods.... after a few weeks, there werent any shrimp left, and he starved.. These guys aren't exactly aggressive, but they have no problem picking pieces off of common plecos at the lfs... silly buggers...
Will devour small pond snails and ramshorns but I had one in a tank with Malaysian trumpet snails and guppies and his mouth became lacerate somehow and he died as a result. I believe MTS shells are too hard for these puffers to break and could possible cause broken jaws or teeth