What fish are poisonous?

I work in a pet shop and we get different kinds of lionfish in all the time ... and my question is ... is one species more poisonous/venomous then the other.

host:Angel topic:what size fish tank and what fish? jackpot:10 points! level:hard Q1)i a,m a fish tank and i can hold 5 female ????? fish in my tank.but i need to have plenty of hiding places in order to have these fish.they also need a heater and filter...

jackpot:10 points host:Angel topic:what fish disease am i? level of difficulty: 1)i am a fish disease that occurs because a fish tank is too dirty and i am white and i will stick in the fish and if you don't cure me quickly then i will spread all over...

Okay sorry this is sorta long. I really need some help figuring this out. Please only serious answers and please don't be rude. I have had fish tanks before. The last one I had before this one was a 55 gallon fish tank but we were moving to South America...

I just came back from visiting Sam's Pet & Aquarium in Marine Parade Central to take a look at some fish as I really want to start a small fish aquarium. It is a packed shop and there are a huge variety of colourful fish to choose from so I took...

in total i have 16 fish: 1 albino corydoras, 1 peppered corydoras, 1 flying fox, 2 glow light tetras, 2 neon tetras, 4 clown loaches, 2 silver sharks, 1 red tailed black shark, 1 albino tiger barb, 1 green tiger barb. i dont know the size of my tank...

A few weeks ago I had one of my tanks wiped out by a very strange disease, and I still haven't figured out what it was. I've termed it "Fish Ebola", but I'll let you decide what it was on your own. Here's what happened. I went to Petco and...

Four times in two months I have dreamt about my fish. The first one I can't remember well. The second one, the tank lid would not close and the fish kept jumping out. I kept having to pick them up and put them in again, being unable to join in the conversation...

I recently got a 30-gallon fish tank and set it up all nicely, however, the person who sold me the fish that I wanted wasn't so knowledgeable and a good number of them died overnight in the bucket I was advised to keep them in while my tank ran for another...