Shot by Lionfish University co-founder Jim Hart, this video showing a Nassau grouper stalking and killing a lionfish in the Cayman Islands might be the best news Caribbean reefs have seen in a while. Lionfish are new to the Caribbean scene, and with no known predators in the area, are rapidly growing out of control (just look at this animated map of their spread!). Lionfish are ravenous hunters and gobble up huge numbers of small fish – enough to spell disaster for a struggling reef.

In the Indo-Pacific where lionfish and grouper are both native, the big fish regularly dine on their poisonous neighbours, but until now, this hasn't been observed in Caribbean or Atlantic waters without 'encouragement' (hand-feeding by divers). If groupers are now recognising lionfish as a food source on their own, it could make them an important ally in controlling invasive populations in the area. 

We're crossing our fingers for the Caribbean, but as you can see in this video from Florida's Coast Watch Alliance, ending the lionfish invasion is going to take a lot more than one hungry grouper!

Top header image: sama093/Flickr