The eco guide to pet fish

Time to help the creatures that, wrested from habitats where they swim thousands of miles, end up atrophying in tanks

We need to talk about Dory. As Pixar's charming version of a tropical blue tang swims on to screens in Finding Dory next month, conservationists fear a wave of inappropriate fish buying.

Finding Nemo, which triggered just such a global craze in 2003, posed less of a threat. Clownfish (Nemo's ilk) are usually bred in captivity for the aquarium trade, but blue tangs are "harvested" from the wild for aquariums, with up to 80% dying during capture and transportation. There is intense pressure on wild populations, especially around coral reefs.