Tony (Treasurechest) is totally right. Not only will certain species of cories sting you...some of the stings hurt like heck! And; they can hurt for several days. It's no worse then a bee sting, but cories DO emit a toxin when they sting you. In fact, some species release a lot of toxins in the bag while being shipped, and can actually poison themselves during the trip. I use a method called "kick the bucket". Before shipping, I'll catch the cories 1st, and kick the bucket every time I pass it. They will release toxins into the water, which you can actually see at the top. It appears as a clear, foamy looking substance at the top. They release most of it into the bucket, so I change the water, and bag them up. They'll still have some left during shipping, but I estimate less then 20%.
From personal experience, the species that have more toxins are Sterbai, Arcuatus, Adolfoi, Haroldschwartzi, Burgessi and possibly Robustus. Coincidentally; these are the same fish that instinctively spread thier fins, as soon as they come out of the water. If you get stung by one of them, I guarantee you'll be more carefull, the next time you go to net them out!
