Many thanks to Jasandjules in our forum for the the following article:

Dwarf puffers - The little fish with BIG character Dwarf puffers (dps) are a relatively new discovery, a few years ago when India started exporting more of their native fish to the States and Europe there were a few relatively obscure puffers about the size of a pea ( hence one of their trade names, the pea puffer).  They were originally assumed to be juvenile examples of already known puffers but it soon became clear this was not the case.

Dps reach an adult size of 1 inch, they have black eyes that turn blue when they are in the light and can move independently (like Chameleons), they can open or close their tail fin depending if they're stopping or going.  They will also 'curl' their tail which can indicate stress or illness but also just a way of maneuverability.  They also can be seen opening their mouths up wide, as if yawning.  Their spots/patches are different colours and shades, from bluish green to black and from light to dark.  They can also change how dark or faded their spots are, depending on their mood.

Determining the sex of dps when they are young is very difficult but easy in adults.  The males have a dark line running down their belly ( as well as more yellow colouring on their bellies).  The vertical line on the males darkens with sexual maturity and during spawning.  The males also have lines or wrinkles behind/above their eyes that the females do not have.  The females body is also much rounder than the males.

Dps are best when kept in a 20 gallon, 1 male and 2 females.  The tank should be very heavily planted so the dps line of sight is constantly broken and they have hiding places.  This will greatly reduce the amount/ chance of aggressive behaviour.  Dps do not need to school so a single dp can be kept, there are also examples of people keeping 20 in a 20g ( very very heavily planted) with few problems, but I wouldn't recommend it, especially if you are new to dps. Ideally dps need about 3 gallons each.

As far as tank mates go, although there are a number of examples of people keeping dps in a community tank, it is not recommended!  Otocinclus make excellent tank mates and very few people have had any problems at all with these coexisting.  Amano or ghost shrimp are another possibilty, but if the dps discover how tasty they are then the peaceful coexistence comes to an end!!  It is probably a good idea, as with any non species tank, when dealing with varying levels of aggression, to add the least aggressive first ( obviously the oto in this case) to allow them to 'claim' territories first.

DPs will eat frozen foods (bloodworms being the most common and popular amongst dp owners), live foods ( blackworms, brine shrimp, snails etc).  They will not eat flake food or freeze dried as a rule, if they do eat any flake food offered it should not be considered a staple diet!  Although dps don't have the need for snails to blunt their teeth the way other puffers do ( most puffers have teeth that continue to grow and grow, like rabbits!), snails can still form a large part of their diet and they will enjoy hunting them in their tank, they are just more likely to suck the snails out of the shell as opposed to crunching down!

Dps are quite hardy and will tolerate varying water conditions but obviously will do best, as with any fish, in optimum water conditions.  They do best at temperatures of 80/26 degrees with a ph of at least 7.

PLEASE NOTE 
Dps are 100% fresh water fish, they do not require any salt, unlike some other fresh water puffers they do not require salt as they grow older, although they will tolerate small increases in salinity they are at optimum health in pure fresh water.  Dps are a very intelligent, interesting fish, they are very aware of 'outside' the tank, and will spend as much time watching you as you do watching them.  Give them a try!!

Many thanks to Lexcy in Abbotsford, BC for all the following information: 

These tiny puffers are imported from India.  They are surprisingly hardy fish and they are also know as pea puffers. They are said to be semi aggressive, but I find they are a good community fish, as long as you have a big enough tank.  Males have a brown vertical line on their belly , which can darken and fade. The females don't have this.  Dwarf puffers seem to eat bloodworms.  If they don't at first, then try little tiny pond snails and ghost shrimp.  They stay tiny at about 3 cm and don't eat your plants.  They don't require any salt, but I do add  a little.  These little guys do have a personality.  They eat right out of my fingers, if I hold the food semi in the water.  They see me when I'm near the tank and all swim up to see what I'm doing.  They are very cute fish.

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