Dot Dash Blenny

Aquarium Requirements

Minimum Tank Size: 75 litres (20 US gallons)

Temperature: 24–28 °C (75–82 °F)

pH: 8.1–8.4

Specific Gravity (Salinity): 1.020–1.025

Alkalinity: 8–12 dKH

Ammonia & Nitrite: 0 ppm

Nitrate:< 10 ppm

Aquascape:
Provide plentiful live rock for grazing and hiding. This species spends most of its time perched on or moving between rocks while grazing on film algae and detritus. The tank should include secure caves, holes, and ledges for resting and retreat. Moderate flow and mature biological filtration are recommended. A tight-fitting lid or mesh cover is important, as blennies may jump when startled.

Diet and Feeding

The Dot Dash Blenny is primarily herbivorous, grazing on benthic microalgae and detritus in the wild. In captivity, it readily accepts a variety of prepared herbivore foods and occasional meaty supplements.

Recommended Foods:

• Algae- and spirulina-based pellets or flakes

• Dried seaweed (nori) and macroalgae sheets clipped in the tank

• Frozen herbivore blends

• Occasional mysis shrimp or finely chopped seafood for dietary variety

Feed 2–3 times daily in small portions. Ensure a consistent supply of algae or plant-based foods to support digestion, maintain colour, and prevent opportunistic nipping at soft corals.

Temperament and Compatibility

The Dot Dash Blenny is peaceful and good-natured, making it an excellent community fish. It may defend its chosen rock or crevice from other blennies or similar-shaped species, but such behaviour is rarely aggressive.

Suitable Tankmates:

• Clownfish, gobies, cardinalfish, firefish, small wrasses, and chromis

• Peaceful invertebrates and reef-dwelling species

Avoid:

• Aggressive or territorial fish (dottybacks, large wrasses, triggers)

• Other Ecsenius or algae-grazing blennies in small aquariums unless adequate space and territory are provided

Reef Compatibility

✅ Reef Safe (with caution)

The Dot Dash Blenny is reef safe and does not harm corals or invertebrates. However, if underfed, it may occasionally nip at soft coral polyps or clam mantles in search of algae. Maintaining a steady, plant-rich diet prevents this behaviour entirely.

Additional Information

Maximum Size: 10–11 cm (4–4.5 inches)

Lifespan: 4–6 years in captivity

Difficulty Level: Easy (hardy, peaceful, excellent algae grazer)

Natural Behaviour: Rock-perching, algae-grazing, curious, territorial around shelter sites

Origin: Indo-Pacific – Indonesia, Philippines, Papua New Guinea, Solomon Islands

Colouration: Creamy to tan base with horizontal rows of dark dots and dashes along the flanks; subtle blue or green iridescence on the head and fins; coloration may vary by region and lighting

Summary

The Dot Dash Blenny (Ecsenius lineatus) is a hardy, peaceful, and attractive herbivorous blenny ideal for reef aquariums. Its characteristic dot-and-dash markings, playful behaviour, and algae-grazing habits make it both functional and visually appealing. Provide abundant live rock, a stable marine environment, and a plant-rich diet, and this endearing species will thrive as a lively, reef-safe resident for years.