I would say, although will let the experts chime in that it is a porcupine fish.
Just out of curiosity why do you ask about releasing them, they are marine fish and unless you are taking them for a tank, then DO NOT kill them, they should be released back into where you caught them. If it is a Porcupine then yes parts of it are poisonous so I certainly would not be eating it or would be careful touching it.
They need a big tank (180g) with a very good protein skimmer if you intend on keeping them.
10g Fry / Hospital / QT tank (as needed)
40g Fry grow out tank
55g Nano Saltwater Reef, 2 Baby Ocellaris Clownfish, Skunk Cleaner Shrimp, Long Tentacle Anemone, Snails and Crabs.
75G - Yellow Labs, Acei, Rusty, Cynotilapia Afra(Mara Rocks), 3 BN Plecos, 2 Male, 3 Female Placidochromis Milomo
90g - Empty - Probably going to be the sump for the 220g.
220g - Empty and will be a slow build to get it running as a mixed reef!