Horned Blenny (Hypsoblennius Exstochilus)

Also Known As: Longhorn Blenny, Caribbean Horned Blenny, Horned Rockskipper

Compatibility and Behavior
The Horned Blenny (Hypsoblennius exstochilus) earns its name with a tiny horn-like cirrus perched above each eye, a subtle bit of character on an otherwise well-camouflaged fish. The body is tan to sandy-brown with mottled, earthy patterning that blends right into rocky reef substrate, built on the classic blenny frame: a rounded, slightly compressed head, big expressive eyes, and that endearing habit of perching on a rock, then hopping to the next good spot as it grazes. It's generally reef safe and peaceful, though worth watching around SPS and clams, since it may occasionally nip small-polyped stony coral or clam mantles. It's non-aggressive as a rule, with one exception: it tends to treat similarly shaped fish as territorial rivals, so it's best kept as the only blenny in the tank unless the system is large. Otherwise it mixes well with clownfish, gobies, wrasses, and other calm community fish.

Aquarium Requirements
Like the Lawnmower Blenny, this is a grazer, so the tank has to feed it. A well-established system with ample natural algae growth is what keeps a Horned Blenny fed, ideally one with multiple swimming levels and plenty of live rock offering caves, crevices, and perches. At least 10 gallons gives it enough rockwork and territory to explore, though more space will cut the odds of friction with similarly shaped tankmates. Moderate to bright lighting helps encourage the algae turf it relies on. A tight-fitting lid is a wise precaution, since blennies are known to jump when startled, especially during acclimation. And supplement its natural grazing with Spirulina, marine algae sheets, and other herbivore preparations to keep its nutrition consistent when the tank's algae runs thin.

Specifications
Approximate Size: 1–1.75"
Diet: Herbivore; grazes on natural algae, supplemented with Spirulina, marine algae sheets, and herbivore preparations
Origin: Caribbean
Care Level: Moderate
Reef Safe: Yes, with some risk to SPS corals and clam mantles
Temperament: Peaceful
Minimum Tank Size: 10 gallons
Special Considerations: Depends on natural algae to graze, so it needs a well-established tank and should be supplemented with Spirulina or algae sheets if growth runs thin; may nip SPS corals or clam mantles, so watch it around those; can be territorial toward similarly shaped fish, so best kept as the only blenny unless the tank is large; can jump, so a tight-fitting lid is recommended