Blue devil damselfish

Care at a glance

The blue devil damselfish is electric blue and for many people the first marine fish they ever see: cheap, hardy and spectacular in colour. In this species the sexes differ clearly: males often have a yellow tail, while females stay entirely blue.

Its name, however, is no joke. Over the years it claims a territory and harasses new arrivals relentlessly, including fish much larger than itself. So add it to the tank last, provide plenty of rock structure, and be aware that removing it later almost always means taking the whole aquascape apart.

Good to know

• Territorial

Best not combined with

• Domino damselfishDascyllus trimaculatus
• Four-stripe damselfishDascyllus melanurus

Related species

• Naso tangNaso lituratus
• Purple firefishNemateleotris decora
• Longnose hawkfishOxycirrhites typus
• Scooter blennySynchiropus ocellatus
• Picasso triggerfishRhinecanthus aculeatus
• Starry blennySalarias ramosus