Pair Signal Blenny — Emblemaria hypacanthus

Introduction to Saltwater Blennies

Blennies are hardy, active, and full of personality, making them a favorite among reef keepers. Found in tropical reefs worldwide, these fish spend most of their time perched on rocks, darting through crevices, or grazing on algae. Their small size, adaptability, and unique behaviors make them an excellent choice for both nano and larger reef tanks. While most blennies are peaceful community fish, some species can be territorial toward similar-looking fish. Their

Care Requirements

vary depending on their dietary needs, with some species specializing in algae control, while others prefer meaty foods.

Care Requirements

Care Level: Easy to Moderate Minimum Tank Size: 20 – 50+ gallons Smaller species (e.g., Tailspot, Bicolor) – 20-30 gallons Larger species (e.g., Lawnmower, Midas) – 40-50+ gallons Aquarium Setup: Requires rockwork and ledges for perching, grazing, and shelter.

Diet & Nutrition

Blennies have species-specific diets, with most being herbivores or omnivores, while some are carnivorous. Herbivorous Species (Algae Grazers): Lawnmower Blenny, Tailspot Blenny Thrive on natural algae growth, nori, spirulina, and algae-based pellets Omnivorous Species: Bicolor Blenny, Midas Blenny Accept both plant matter and meaty foods Carnivorous Species: Some blennies prefer a protein-rich diet of mysis shrimp, brine shrimp, and small crustaceans Providing a balanced diet ensures optimal coloration, energy levels, and long-term health.

Lifespan & Growth Rate

Lifespan: 4-6+ years Growth Rate: Moderate – Most species stay under 5 inches Blennies are long-lived for their size, making them a low-maintenance but rewarding addition to a reef tank.

Temperament & Compatibility

Temperament: Peaceful to Semi-Aggressive – Some species can be territorial toward similar fish Reef Safe? Yes, but some may nip at corals or clams Blennies are typically peaceful but may become aggressive toward fish with similar body shapes, such as gobies or other blennies. To minimize aggression: Keep only one blenny per tank, unless in a large system with multiple territories. Avoid housing them with larger aggressive species that may bully or outcompete them for food. Most blennies ignore corals, but some species—like the Bicolor Blenny—have been known to nip at fleshy corals when underfed.

Common Challenges & Considerations

Jumping Risk: Blennies are notorious jumpers—a tight-fitting lid is strongly recommended. Algae Dependency: Herbivorous species require a steady source of algae to remain healthy. A well-established tank is ideal before introducing an algae-grazing blenny. Territorial Behavior: Can be aggressive toward similar-looking fish or other bottom dwellers in smaller tanks. Water Conditions Temperature: 74-80°F dKH (Alkalinity): 8-12 pH: 8.1-8.4 Specific Gravity: 1.020-1.025 Blennies adapt well to stable reef conditions but require a well-oxygenated tank with moderate water flow.

Color Varieties & Popular Species

Blennies come in various colors and patterns, often featuring striking facial markings and expressive eyes. Popular species include: Lawnmower Blenny (Salarias fasciatus) – Excellent algae grazer with a mottled brown appearance Tailspot Blenny (Ecsenius stigmatura) – Small, peaceful, with a bright orange tail spot Midas Blenny (Ecsenius midas) – Golden-yellow body, known for its eel-like swimming motion Bicolor Blenny (Ecsenius bicolor) – Half purple, half orange, can be more aggressive than other species