The red rock cod looks like a stone often with a red belly. They can be dangerous to handle, but catfish do not attack. Surgeonfish Beautiful tropical fish. There are many species all characterized by a scalpel like spine protruding from the junction of their body and tail. Injuries only happen when handling fish.
Surgeon fish can also cause ciguaterra poisoning if eaten.
The rings can turn to a bright blue to show the change of mood of the octopus. The bite might be painless, but this octopus injects a neuromuscular paralyzing venom. The venom contains some maculotoxin, a poison more violent than any found on land animals. The nerve conduction is blocked and neuromuscular paralysis is followed by death. The victim might be saved if artificial respiration starts before marked cyanosis and hypotention develops.