Red Tail Blenny

Species Profile

• Scientific Name: Ecsenius bicolor
• Common Name: Red Tail Blenny (also known as Bicolor Blenny)
• Adult Size: 4–4.5 inches (10–11.5 cm)
• Life Expectancy: Up to 5 years in captivity with proper care
• Habitat:
  • Found in coral reefs and rocky lagoon areas of the Indo-Pacific
  • Lives among rock crevices and coral rubble

  • Spends time perched on rocks or darting between hiding spots

Tank Requirements

• Minimum Tank Size: 30 gallons for a single specimen
  Larger tanks required if housing with other blennies or similarly shaped fish
• Ideal Temperature: 72–78°F (22–26°C)
• pH Range: 8.1–8.4
• Water Hardness: 8–12 dKH
• Temperament:
  • Generally peaceful
  • Can be territorial with similar-looking fish, especially other blennies
  • Best in a reef or community tank with ample rockwork and hiding places

  • May nip at fleshy corals or clam mantles on occasion, though not common

Diet & Nutrition

• Primarily herbivorous
• Loves microalgae and macroalgae
• In captivity, diet should include:
  • Spirulina-based foods
  • Algae sheets (nori)
  • High-quality marine flakes and pellets
  • Occasional mysis or brine shrimp

• Important to provide a plant-based diet to prevent malnutrition

Breeding & Spawning

• Egg-layer
• Spawning can occur in captivity but is rare
• Males may guard and fan eggs laid in rock crevices or shells

• Requires stable water conditions, pair bonding, and quiet environment

Appearance

• Distinct two-tone coloration:
  • Front half (head and body): deep blue to purple
  • Back half (tail): bright orange to red
• Slender body, blunt head with large expressive eyes

• Often perches upright or watches surroundings from rocks

Distinctive Features

• Popular for its vivid bicolor appearance
• Known for its fun personality and “perching” behavior
• Helps control algae in tanks

• Great addition to reef aquariums, provided they are well-fed