Meiacanthus grammistes 
Mekong giant catfish 
Melon Butterflyfish 
Messmate Pipefish 
Mexican blindcat 
Mexican Goatfish 
Mexican hogfish 
Michel's ghost goby 
Midas cichlid 
Midas Combtooth Blenny 
Midget flathead 
Midnight Snapper 
Mikrogeophagus altispinosus 
Mimic blenny 
Mimic Surgeonfish 
Mimic Surgeonfish 
Miracle triplefin 
Mirror Butterflyfish 
Mobile logperch 
Moluccan Cardinalfish 
Monarch Damselfish 
Monrovia Doctorfish 
Moon wrasse 
Moonlighter