Midas blenny

1) Where they come from

Midas blennies come from the Red Sea and Indo-Pacific reef zones, where they hang around rocky ledges and coral rubble. In the wild you’ll often see them hovering in the water column like a tiny anthias… then zipping back into a hole the second something looks at them funny.

2) Setting up their tank

Give them rockwork with real caves and crevices, not just a pretty scape. A Midas that can’t claim a bolt-hole stays nervous, hides all day, and is way more likely to pick fights once it finally comes out.

Tank size-wise, I like them in 30+ gallons, and they’re even better in a 40 breeder or larger where they’ve got some open water to do their hovering. They’re active little noodles.

• Rockwork: at least a couple of tight caves/holes they can wedge into
• Open swimming lane: they’ll use the mid-water more than most blennies
• Moderate flow: they handle flow well, but still want calm pockets near their hideout
• Lid/mesh top: they can jump, especially during spats or first week jitters

3) What to feed them

People see “blenny” and assume they’re an algae grazer. Midas blennies are more planktivorous—think meaty bits in the water column. Mine always did best with small foods offered more than once a day.

• Frozen: mysis, brine (better as a treat), finely chopped krill, copepod blends
• Pellets: small marine pellets (they usually learn fast if other fish are eating them)
• Flake: works in a pinch, but don’t make it the whole diet
• Occasional treat: live pods if you’ve got them—great for shy new arrivals

4) Behavior and tankmates

Midas blennies have big personality. They perch, they hover, they do quick little sprints, and they’ll watch you like a curious puppy. Most of the time they’re peaceful, but they can get spicy with similar-shaped fish or other blennies that want the same real estate.

They’re usually reef-safe with corals and inverts. The main “issue” is them deciding a favorite cave is worth defending.

• Generally good tankmates: clownfish, gobies, wrasses (most), tangs in larger tanks, cardinalfish, chromis
• Use caution with: other blennies, some dottybacks, similarly colored/yellow fish in small tanks
• Avoid: aggressive bullies that camp caves (big hawkfish, nasty damsels), fish that will constantly harass it into hiding

5) Breeding tips (if you’re curious)

They can spawn in captivity, but raising the babies is the hard part. Like many blennies, they’re cave spawners—eggs get laid in a hole, and the male tends to guard and fan them. In a community tank you might never notice until you spot a super-defensive blenny glued to one crevice.

6) Common problems to watch for

Most Midas blenny issues come down to stress, shipping, and being outcompeted for food. A healthy one should look full-bodied, have clear eyes, and spend at least part of the day out in the open doing that hover-swim.

• Jumping: especially the first week, during chasing, or if startled—use a lid
• Not eating at first: common with new/shy fish—offer small meaty foods and feed near their hideout
• Getting bullied: watch for nipped fins and a fish that never leaves its cave
• Ich/velvet risk: they’re not special snowflakes, but they can come in carrying parasites like any marine fish
• Weight loss: can happen if you feed “algae blenny style” and they don’t get enough meaty food