freshwater amazon puffers

Question
do these fish need any salt in the tank?  

Answer
Hi Cindy;

Colomesus asellus can tolerate salt but it isn't needed. They tend to cruise back and forth over a long period of time between the coastal rivers and inland fresh waterways, but not entering the ocean. They need plenty of good filtration, lots of water changes and gravel vacuuming (25% weekly), and food like snails and other mollusks with hard shells to keep their beaks or "teeth" worn down. The upper and lower beaks need trimming every few months otherwise. Here is a list of web pages to know more about them;

http://animal-world.com/encyclo/fresh/Puffers/AmazonPuffer.php
http://www.thetropicaltank.co.uk/Fishindx/puf-asel.htm
http://www.aquahobby.com/gallery/e_Colomesus_asellus.php
http://www.pufferfish.co.uk/aquaria/species/pufferfish/types/coloasel.htm
http://www.fishprofiles.com/files/profiles/293.htm
http://www.answers.com/topic/colomesus

Have fun! Puffers are very cool and intelligent fish.

At Your Service;
Chris Robbins