Pet Wiki

Not furry, but we like them anyway.

Bicolor Blenny

Ecsenius bicolor

Also called Bicolor coralblenny, Bicolor combtooth blenny, Flame tail blenny, Salarias bicolor (original name)

SpeciesShort profile

From Indo-Pacific: Maldives to the Phoenix Islands, north to the Ryukyu Islands and south to the southern Great Barrier Reef, throughout Micronesia12

At a glance the quick version

Length10 to 11 cm123
Sizesmall
Eye-catching two-tone colour
Lots of personality as it perches and peeks from holes
Helps graze algae in the aquarium
3

Looks how to spot one

Slender combtooth blenny

A small, slim blenny best known for its two-tone look: dark blue to brown at the front and orange at the back. Some fish show other colour phases, with a dark back, a broad white side band and a yellow or dusky tail.13

Coloursdark blue to brownorangeyellowwhite band (some phases)13

Personality what they are like

Generally peaceful and full of character, though it may nip at other blennies, gobies or dartfish.3

Daily activity how busy a day looks

Perches on rocks and pops in and out of crevices and holes.31

Grooming and care the hands-on bits

Keep it well fed with plant-based foods and provide lots of rock with crevices and holes to claim as a home.3

Home where they are happiest

Minimum about 30 US gallons (114 L). Saltwater at about 22 to 26 °C, pH 8.1 to 8.4, dKH 8 to 12, specific gravity 1.020 to 1.025. Wild fish live on clear lagoon and seaward reefs with mixed corals and algae-covered rock, at 1 to 25 m.31

Food basics what goes in the bowl

Mainly herbivorous. Offer algae and vegetable-based foods along with what it grazes from the rocks.31

Company who they like around

Lives singly in the wild, often in an old tube or hole. Best kept as the only blenny of its kind.13

The story where it all began

Francis Day described it in 1888 as Salarias bicolor. Over time it collected several other scientific names before settling in the genus Ecsenius. It is a regular in the aquarium trade.2

Fun facts for the dinner table

  1. 1

    Wild fish often make their home in an empty tube left by a worm or other animal.1

  2. 2

    It has several distinct colour phases, not just the classic blue-and-orange look.1

  3. 3

    The eggs are sticky and are attached to a surface by small threads.1

Recognised by the official bits

IUCN Red List
Least Concern (assessed 2009)1

The care rhythm a typical week and year

A typical home-care rhythm for a Bicolor Blenny. A starting point, not a vet's advice.

Owner questions the things everyone asks

How often should I feed my Bicolor Blenny?

Feed small amounts once or twice a day, as per Furry Diary's starting plan. Offer plant-based foods like algae and vegetable-based preparations. For exact amounts, check the food label and ask your vet.31 Pet Wiki plan

What does a Bicolor Blenny eat, and what should it never eat?

Your Bicolor Blenny is mainly herbivorous, so offer algae and vegetable-based foods along with what it grazes from the rocks. As for what it should never eat, that varies by individual; ask a good breeder or an exotic-pet vet for specific foods to avoid.31

How much space does a Bicolor Blenny need?

A minimum of about 30 US gallons (114 L) is recommended. Provide lots of rock with crevices and holes for it to perch and claim as a home.31

What temperature, light or water does a Bicolor Blenny need?

Keep saltwater at about 22 to 26 °C, pH 8.1 to 8.4, dKH 8 to 12, and specific gravity 1.020 to 1.025. Furry Diary suggests checking temperature daily and salinity weekly.31 Pet Wiki plan

How often should I clean a Bicolor Blenny's home?

Furry Diary's starting plan includes a weekly glass clean and a 10-20% water change every two weeks. Also top up evaporation daily with fresh RO water, not salt water. Pet Wiki plan

Can a Bicolor Blenny live with others?

Generally peaceful, but may nip at other blennies, gobies or dartfish. Best kept as the only blenny of its kind, as it lives singly in the wild.31

How long does a Bicolor Blenny live?

Lifespan is not specified in the information provided; it varies. Ask a good breeder or an exotic-pet vet for typical lifespan.

Can I handle a Bicolor Blenny?

Handling is not recommended; it's a fish and should not be handled. Provide a stress-free environment with plenty of hiding spots.31

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.

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Where this comes from

Every fact on this page has a numbered source. Spotted an error? [email protected].

  1. FishBase: Ecsenius bicolor fishbase.seused for distribution, size, depth, habitat, colour phases, behaviour, IUCN
  2. Wikipedia: Ecsenius bicolor en.wikipedia.orgused for history, other names, size
  3. LiveAquaria: Bicolor Blenny liveaquaria.comused for care, tank size, water parameters, diet, temperament

Checked 2026-09-30. Text is written in our own words from these sources.