The peacock grouper is an invasive fish in Hawaii. It was introduced in the 1950s from French Polynesia. The goal was to add to Hawaii’s food source, but this backfired because the fish was found to contain high levels of ciguatera toxin, which leads to ciguatera poisoning in humans. Peacock groupers accumulate ciguatera from eating smaller reef fish, which feed on the dinoflagellates that produce the toxin. The toxin is harmless to fish, but when ingested by humans, it can cause nausea, pain, cardiac, and neurological symptoms.
Sea hare ink, on the other hand, is toxic to their predators but not to humans. All the more reason to love them.