Orange Tail Bicolor Blenny – Ecsenius bicolor

Quarantine and Conditioning Started on 9/18 - Release Date: 10/8
If you wish to purchase this fish before the release date we will hold the fish for you. Let us know your desired ship date. If there is an issue during the Quarantine process, we will issue a refund.

The Orange Tail Bicolor Blenny (Ecsenius bicolor) is a small Indo-Pacific combtooth blenny known for its striking two-tone coloration and expressive appearance. In the classic bicolor color phase, the front portion of the fish is very dark brown to nearly black, contrasting sharply with a bright yellow to orange posterior body and tail. FishBase documents this dark-front/yellow-rear pattern as one of several naturally occurring color phases in the species. FishBase

Ecsenius bicolor is widely distributed throughout the Indo-Pacific, ranging from the Maldives eastward to the Phoenix Islands, north to the Ryukyu Islands, south to the southern Great Barrier Reef, and throughout Micronesia. It is a reef-associated species found at approximately 1–25 meters (3–82 feet). FishBase

In nature, Bicolor Blennies inhabit clear lagoons and seaward reefs with mixed corals and algae-covered rock. FishBase also documents individuals occupying abandoned tubes, reflecting the species' preference for small holes and protected retreats within reef structure. FishBase

This behavior translates particularly well to a reef aquarium. A Bicolor Blenny will typically make use of holes, crevices and other sheltered locations in the rockwork while spending time observing its surroundings and moving between perches.

Despite its relatively small size, the Bicolor Blenny has plenty of personality. FishBase records a maximum total length of approximately 11 cm (4.3 inches), making it suitable for considerably smaller aquariums than many larger reef fishes. FishBase

This specimen is offered as one of Dr. Mac’s Quarantined and Conditioned Fish.

Care Guide

Scientific Name: Ecsenius bicolor (Day, 1888)
Common Name: Orange Tail Bicolor Blenny
Other Common Names: Bicolor Blenny, Bicolor Combtooth Blenny
Family: Blenniidae
Availability: Conditioned & Quarantined
Care Level: Easy to Moderate
Temperament: Generally peaceful; may become territorial toward similar blennies
Reef Compatibility: Reef compatible
Minimum Aquarium Size: 30 gallons recommended
Maximum Size: Approximately 4.3 inches (11 cm total length) FishBase
Diet: Omnivorous grazer; provide substantial plant/algal foods as part of a varied diet
Temperature: 75–80°F
Specific Gravity: 1.023–1.026
pH: 8.1–8.4

Aquarium Requirements: Provide an established aquarium with plenty of rockwork containing holes, crevices and protected retreats. This corresponds well with the species' natural association with mixed coral, algae-covered rock and abandoned tubes. FishBase

Diet and Feeding: Provide a varied diet with a strong plant-based component, including marine algae and quality spirulina or algae-based preparations. A mature aquarium with natural algal growth provides additional grazing opportunities. Supplemental nutritionally complete marine foods can be offered to maintain a varied diet.

Temperament: Generally peaceful with unrelated community fishes, but individuals can defend a preferred hole or section of rockwork. Extra care should be taken when keeping it with other Ecsenius or similarly shaped blennies, particularly in smaller aquariums.

Reef Compatibility: Reef compatible. The species' small adult size and natural association with coral-and-algae reef environments make it well suited to established reef systems. FishBase specifically describes its habitat as clear lagoon and seaward reefs containing mixed corals and algae-covered rocks. FishBase

Natural Habitat: Reef-associated at approximately 1–25 meters, inhabiting tropical Indo-Pacific lagoon and seaward reef environments. FishBase

Reproduction: Ecsenius bicolor is oviparous. FishBase reports that the eggs are demersal and adhesive, attaching to the substrate, while the larvae become planktonic.