Midas Blenny Identification Guide
Learn to distinguish this mimicking blenny from the anthias it imitates using fin shape and body form.
Read the full Midas Blenny encyclopedia entry →
Key identification features
- Elongated, slightly compressed body most often colored bright golden-yellow to orange
- Some individuals show a duller brown or blue-tinted form with fine blue lines near the eyes when not mimicking
- A single long, continuous dorsal fin running nearly the length of the back without a notch
- Rounded, unforked or only slightly forked tail fin, unlike the fins of the fish it mimics
- Small comb-like teeth and a blunt head typical of blennies; grows to about 13 cm
Common look-alikes
- Lyretail anthias: the fish midas blennies commonly mimic; anthias have a deeply forked, lyre-shaped tail and separate dorsal fin elements, while the blenny's tail and single dorsal fin are simpler in shape
- Other yellow damselfish or basslets: generally deeper-bodied with forked tails, lacking the blenny's elongated shape and continuous dorsal fin
Where you'll see one
Found on Indo-Pacific and Red Sea coral reef slopes and drop-offs, often swimming openly alongside schools of anthias it resembles, retreating into reef holes when threatened.
Frequently asked questions
How do I tell a midas blenny from the anthias it mimics?
Check the tail and dorsal fin: the blenny has a rounded tail and one continuous dorsal fin, while anthias have a deeply forked tail and a distinctly notched dorsal fin.
Why does a midas blenny sometimes look blue instead of yellow?
Midas blennies can shift between a golden mimicry coloration and a duller blue-brown form with facial lines when not swimming among anthias schools.