Description

The Bicolor Blenny (Ecsenius bicolor) is a hardy, quirky, and fun-to-watch reef-safe fish that’s ideal for both beginner and experienced aquarists. Its distinctive two-tone coloration and comical perching behavior make it a standout in smaller reef aquariums.

🔷 Species Overview

• Scientific Name: Ecsenius bicolor

• Common Names: Bicolor Blenny, Two-tone Blenny

• Origin: Indo-Pacific (Red Sea to western Pacific)

• Size: Up to 4 inches (10 cm)

• Lifespan: 4–6 years

• Temperament: Peaceful, with some territorial tendencies

• Reef Safe: Yes (with minor caveats)

• Care Level: Easy

🐟 Appearance

• Coloration:

  • Front half is a deep blue to purple

  • Back half is bright orange to yellow (hence “bicolor”)

• Body Shape: Slender, eel-like body with a blunt head

• Eyes: Large and expressive

• Behavior: Known for sitting on rocks and “watching” their surroundings

🏝️ Tank Requirements

🍽️ Diet

• Type: Herbivore/Omnivore

• Feeding Frequency: 1–2 times per day

• Diet Includes:

  • Algae (especially hair algae and film algae)

  • Spirulina flakes/pellets

  • Nori (dried seaweed)

  • Occasional mysis/brine shrimp or finely chopped seafood

Important: Ensure they get enough algae in their diet to prevent starvation in low-algae tanks.

⚠️ Behavior and Compatibility

• Temperament: Generally peaceful; can be territorial with similar-shaped blennies or gobies

• Tankmates:

  • Good with most peaceful reef fish

  • Avoid housing with other algae-blennies unless in large systems

• Reef Compatibility: Mostly reef-safe

  • May nip at fleshy LPS corals (e.g., acans, brains) if underfed or bored

  • Generally ignores SPS, zoas, and soft corals

🛠️ Care Tips

• Needs plenty of hiding spots and perches

• Can jump — use a secure lid

• Supplement with algae-based foods in low-nutrient systems

• Avoid aggressive tankmates like triggers or large wrasses

✅ Pros

• Great algae grazer

• Full of personality and fun to watch

• Hardy and beginner-friendly

• Small size makes it nano-tank friendly

❌ Cons

• May nip corals if underfed

• Territorial with similar fish

• Needs algae or algae-based diet