Striated blenny

Where they come from

Striated blennies (Hypsoblennius striatus) are little rock-huggers from the tropical western Atlantic and Caribbean. You will usually find them in shallow reefs, rubble, and around pilings where there are holes and crevices to duck into. If you have ever snorkeled and seen a tiny face peeking out of a barnacle cluster, that is the vibe.

Setting up their tank

This is an advanced fish mostly because it does not tolerate sloppy swings and it can be a pain to get eating well if it arrives skinny. Once settled, they are tough in the day-to-day, but the first few weeks matter a lot.

Give it a tank that is mature and has real micro-life. Think established rock, film algae, little pods, the whole deal. A brand-new sterile reef often ends up with a blenny that stares at you like you are offering it cardboard.

• Tank size: I would start around 20 gallons for a single fish, bigger if you want to keep other bottom-territory fish.
• Rockwork: lots of holes and short tunnels. They want a home base they can wedge into.
• Flow: moderate. They like oxygen-rich water, but they do not want to be blasted out of their perch all day.
• Lighting: whatever your reef runs. What matters is you grow some natural grazing and keep the fish feeling secure.
• Cover: a lid. Blennies can hop, especially during spats or if startled at night.

What to feed them

In the wild they pick at algae, tiny crustaceans, and whatever edible bits they can scrape off rock. In a tank, some individuals go straight onto prepared food, and some make you work for it. Plan for a slow ramp-up.

• First foods that usually get a response: live or enriched baby brine, copepods, small mysis, finely chopped shrimp.
• Once they are taking frozen: mysis, brine plus spirulina, calanus, and small meaty blends.
• For the grazers: nori on a clip, spirulina flakes, and pellets with a good algae component (tiny size pellets help).
• Feeding rhythm: small amounts 1-2 times a day at first. After they are stable, they are fine on a normal reef schedule if they are keeping weight.

How they behave and who they get along with

They are classic blenny personality: curious, a little stubborn, and very attached to a specific patch of real estate. Most of the time they are funny and peaceful, but they can flip a switch if another fish crowds their hole.

• Good tankmates: peaceful reef fish that live in the water column (chromis, small wrasses with mellow temperaments, gobies that keep to their own burrow).
• Use caution with: other blennies, similarly shaped fish, and perchers that want the same ledges (some hawkfish, dottybacks, aggressive gobies).
• Bad mix in smaller tanks: multiple blennies unless the tank is large with lots of separated rock zones.

Breeding tips

They are cave spawners. A male will claim a snug hole and try to lure a female in to lay eggs on the inside surface. In home tanks, you can get spawning behavior if you keep a well-fed pair and give them multiple tight cavities.

• Provide tight nests: small rock holes, empty snail shells, or short PVC elbows hidden in rock.
• Condition with food: a mix of meaty frozen and algae-based foods. Keep them from getting skinny.
• Egg care: the male typically guards and fans the clutch. Do not mess with the nest rock if you can avoid it.

Common problems to watch for

Most issues I see with this species come from three things: arriving underfed, getting outcompeted at mealtime, or being placed in a tank with a territorial jerk.

• Refusing food early on: try live foods, feed right at the cave entrance, and dim the lights for the first day or two.
• Weight loss even though it is pecking: add targeted meaty feeds. Rock grazing alone rarely keeps a new import in good shape.
• Jumping: usually after a scare or during chasing. Keep a lid and cover gaps around cords.
• Fin damage and scraped faces: usually from fighting over a hole. Add more hiding spots or separate fish.
• Marine ich/velvet risk: they are not magically immune. Quarantine is your friend, especially because stress hits them hard in the first couple weeks.