Barnacle Blenny Acanthemblemaria Macrospilus

Overview
The Barnacle Blenny is a charismatic and quirky marine fish known for its comical expressions, darting movements, and fascinating behavior. These small, tube-dwelling blennies are often seen poking their heads out of barnacles, rock crevices, or coral holes, making them highly entertaining to observe. Despite their small size, they exhibit big personalities, often showing curiosity and territorial displays toward nearby fish or even their keepers.
Origin
Native to the Eastern Pacific Ocean, Barnacle Blennies are most commonly found along the coastlines of Mexico, particularly in the Gulf of California. They inhabit shallow reef environments and rocky intertidal zones, often sheltering in empty barnacle shells or other small crevices in coral rubble and rocky substrates.
Feeding
In the wild, Barnacle Blennies feed primarily on zooplankton and other tiny organisms drifting in the water column. In captivity, they accept a range of finely sized meaty foods:
Live or frozen mysis shrimp
Baby brine shrimp
Copepods
High-quality marine micro pellets
Finely chopped seafood or enriched frozen blends
Feed small amounts 1–2 times daily, making sure food drifts near their hiding spots for easy capture.
Tank Mates
Barnacle Blennies do best in peaceful, reef-safe community tanks with other non-aggressive species. Ideal tank mates include:
Gobies
Clownfish
Cardinalfish
Dwarf wrasses (peaceful species)
Small reef-safe invertebrates (such as cleaner shrimp)
Avoid housing them with large or highly territorial species, especially those that may compete for similar shelter or harass the blenny in its burrow.
Aggression
While generally peaceful, Barnacle Blennies can be territorial—particularly toward other blennies or fish that invade their space. They may display fin-flaring or quick lunges from their burrow to intimidate rivals. It's best to keep only one Barnacle Blenny per tank unless housed in a very large system with ample hiding spots.
Experience Level
Beginner to intermediate. Barnacle Blennies are hardy and relatively undemanding as long as they have appropriate hiding spots and stable, clean water. Their unique behavior makes them a favorite for nano reef tank enthusiasts and seasoned aquarists alike.
Water Parameters
Temperature: 22–27°C (72–80°F)
pH: 8.1–8.4
Salinity: 1.023–1.025
dKH: 8–12
Tank Size: Minimum 10 gallons (nano reef suitable, with strong emphasis on available hiding spots)
Special Notes
Provide multiple small crevices, shells, or barnacle clusters as shelter.
They spend most of their time in their burrow, darting out to feed or chase away intruders.
They are reef-safe and won’t harm corals or invertebrates.
Their expressive faces and peeking behavior make them highly entertaining additions to a reef aquarium.