Striped clingfish

Where they come from

Striped clingfish (Derilissus vittiger) are tiny reef-associated fish that show up in the tropical western Atlantic and Caribbean. Think shallow reef rubble, sponges, and little crevices where a fish the size of your pinky nail can disappear instantly.

They are called clingfish for a reason: that suction disk under the body is their whole deal. In the wild they spend a lot of time stuck to rock, tucked under ledges, and hunting micro-prey at close range.

Setting up their tank

If you try to keep this fish like a "normal" nano reef fish, it usually ends in a slow fade. The tank has to be built around how small and cryptic they are, and how they feed.

• Tank size: a mature nano can work, but stability matters more than gallons. I like 10-20g dedicated, or a larger reef where you can protect them from competition.
• Maturity: run the tank long enough to have pods and micro-life everywhere. New sterile rock and fresh sand are a rough start for them.
• Rockwork: lots of tight caves, rubble zones, and overhangs. They want many "parking spots" where they can cling and watch.
• Flow: moderate with calmer pockets. They do fine in flow if they can duck behind rocks. Avoid blasting every surface.
• Lid: cover the tank. They are not classic jumpers, but tiny fish find tiny gaps, especially during acclimation stress.
• Filtration: normal reef filtration is fine, but avoid big, hungry mechanical setups that strip every bit of planktonic life if you are relying on pods.

Lighting is more about what you are keeping with them than what they need. They do not care about bright light, but they do care about having shaded areas. I always build at least one dark side of the scape.

What to feed them

Feeding is the make-or-break part. Most clingfish come in skinny and they do not compete well at the water surface. You need to get food right in front of their face, repeatedly, and ideally offer small live foods at first.

• Best starters: live baby brine (enriched), copepods, small amphipods, live blackworms (rinsed, marine use is a bit messy but they love them), and live mysis if you can get small ones.
• Once settled: frozen cyclops, frozen calanus, finely chopped mysis, roe, and other tiny meaty bits. Some will take small pellets eventually, many will not.
• How to deliver: use a pipette or turkey baster and target feed into their little cave zone. Turn flow down for 5-10 minutes if you have to.

If you keep them in a community reef, plan on feeding the tank first (so the pigs are distracted), then target the clingfish. I have had the best luck feeding smaller amounts more often rather than one big dump.

How they behave and who they get along with

They are shy, low-key fish. Most of the time you will see a little striped face peeking out, then they scoot a few inches and stick again. They do not "cruise" like gobies or blennies.

Tankmate selection is basically about two things: competition at feeding time, and whether anything sees them as a snack.

• Good neighbors: tiny, peaceful fish that do not mob food (small gobies, some small firefish in bigger tanks), and gentle inverts.
• Risky: dottybacks, hawkfish, wrasses (even small ones), bigger clownfish, damsels, and anything that hunts pods aggressively.
• Also risky: large peppermint shrimp, big coral banded shrimp, and predatory crabs. A clingfish is bite-sized.
• Best setup: species-only or a very calm nano with one or two other tiny fish, plus a strong pod population.

Breeding tips

Breeding in home tanks is not common, mostly because people do not keep them in pairs long-term and because larvae (if they go pelagic) are a whole extra project. That said, clingfish in general lay adhesive eggs in sheltered spots, and the male often guards.

If you want to take a swing at it, give them lots of tiny caves and removable "egg sites" like small shells, little pieces of PVC tucked under rock, or flat rubble under an overhang. Feed heavy with small meaty foods and keep the tank peaceful.

Common problems to watch for

• Slow starvation: the #1 issue. They are eating "something" but not enough. Fix with target feeding, more frequent small feeds, and live foods during the first weeks.
• Getting outcompeted: even peaceful fish can steal every bite. If your clingfish only eats when nobody is watching, it will usually lose weight.
• Intake/overflow accidents: they can stick to weird places and end up pinned or sucked in. Guard every intake.
• Shipping/collection stress: they often arrive dehydrated-looking and skittish. Gentle acclimation, low light, and immediate access to live foods helps a lot.
• Medication sensitivity: tiny scaleless-ish fish can react badly to heavy dosing. If you quarantine, go slow and research the exact meds and concentrations.

If you are doing everything right and it still keeps losing weight, do not keep "waiting it out". Move it to a quiet, established small tank where you can control feeding and watch it closely. With this species, the window to turn things around can be short.