Ocular Blenny
Ecsenius oculus
Inhabiting sunlit Pacific reef flats, this herbivorous blenny requires a 60L tank with plenty of live rock. A secure lid is strictly required to prevent jumping.
Wassertemperatur
23 - 27 °C
pH-Wert
8.1 - 8.4
Wassertyp
Meerwasser
Tankfüllstand
Unten
Erwachsenengröße
6 cm
Mindesttankvolumen
>= 60 L
Mindestgruppe
>= 1
KH
8 - 12 dKH
Artbeschreibung
Geographical Origin and Habitat: This species inhabits the tropical Western Pacific Ocean, from the southern Ryukyu Islands and Taiwan down to the Philippines, Indonesia, and Palau. It is found on shallow, sunlit reef flats and crests at depths of 1 to 15 meters, where algae are abundant.
Taxonomy and Morphology: Member of the Blenniidae family, subfamily Salariinae. It has a cylindrical, scaleless body, large expressive eyes, and tiny branched cirri above each eye orbit. Adults reach a maximum length of approximately 6.0 centimeters.
Social Behavior: A peaceful, alert, and mostly solitary fish. It spends its time perched on live rock to monitor the surrounding area, retreating backward into its favorite crevice when threatened or during the night to sleep safely.
Coloration and Sexual Dimorphism: The body coloration is tan to light brown, marked with 4-5 prominent dark brown or black ocelli (eye-like spots) bordered by white along the dorsal side. There is no visible sexual dimorphism between males and females.
Pflege, Zucht und Mitbewohner
Aquarium Setup: A minimum tank size of 60 liters is required, featuring a rich arrangement of live rock with tiny cracks and caves to provide vantage points and hideouts. A tight-fitting lid or mesh cover is strictly required, as this blenny is known to jump when startled.
Diet and Feeding: Herbivorous. It feeds naturally by scraping microalgae and organic biofilm off hard surfaces. In captivity, feed a diet high in vegetable matter, such as spirulina flakes, sheets of nori, herbivore pellets, and occasional small frozen foods like mysis.
Water Quality: Keep reef parameters stable: temperature 23 to 27 °C, pH 8.1 to 8.4, and specific gravity 1.020 to 1.025. Standard marine filtration, a reliable protein skimmer, and moderate water movement are necessary to maintain highly oxygenated water.
Compatibility and Cohabitation: An excellent reef-safe addition that will not harm corals or ornamental invertebrates. Peaceful with open-water fish, but can display territorial aggression toward other blennies or benthic fish of similar size and shape in smaller tanks.
Aquarium Breeding: Oviparous. Females deposit adhesive eggs in a crevice or shell, which are then guarded and aerated by the male until they hatch. Captive breeding is very rare due to the difficulties associated with raising the microscopic pelagic larvae.
Risks and Diseases: Starvation is a major risk in newly set up, sterile tanks lacking microalgae. Because it is scaleless, it is sensitive to copper-based treatments and sudden changes in salinity. Ensure the tank is securely covered to prevent jumping.
Geografische Herkunft und Verbreitung
This species inhabits the tropical Western Pacific Ocean, from the southern Ryukyu Islands and Taiwan down to the Philippines, Indonesia, and Palau. It is found on shallow, sunlit reef flats and crests at depths of 1 to 15 meters, where algae are abundant.
Ursprung
Tropische Ozeane und RiffeSüd- und SüdostasienOstasien
Fischprofil
- Temperament
- Territorial
- The Ecsenius oculus is highly regarded for its comical, observant, and largely peaceful personality. It often rests visibly on rocks, seemingly watching the aquarist just as closely as it watches its tank mates. While it boldly defends its specific burrow from intruders, it is otherwise completely indifferent to other fish species. This combination of spunk and general peacefulness makes it an enduring favorite in the marine hobby.
- Diät
- Herbivore
- As a dedicated herbivore, the Ecsenius oculus spends the majority of its day scraping microalgae from live rock and glass. Its diet must be heavily supplemented with high-quality marine algae, spirulina flakes, and specialized herbivore pellets. Providing a mature aquarium with plenty of natural algal growth is essential for its long-term health. While it may occasionally nip at meaty foods, plant matter should remain its primary nutritional source.
- Lebenserwartung
- 2-5 years
- Erwachsenengröße
- 6 cm
- Geschlechterverhältnis
- Flexible
- It is generally best to house the Ecsenius oculus individually, as they are notoriously intolerant of their own kind in confined spaces. Males are particularly combative with one another and will fight relentlessly over prime rockwork territories. While a confirmed male-female pair can sometimes be kept in a larger system, sexing them visually is quite difficult. Introducing multiple specimens simultaneously to a large tank is the only way to potentially mitigate severe aggression.
- Fütterungsfrequenz
- Twice daily
- Because of its constant grazing habits, the Ecsenius oculus benefits from multiple small feedings rather than one large meal. Offering prepared herbivore foods two to three times a day closely mimics its natural feeding rhythm. If the aquarium has abundant natural microalgae, the frequency of supplemental feeding can be slightly reduced. Ensuring continuous access to food prevents malnutrition and keeps its immune system strong.
- Bioload
- Low
- The Ecsenius oculus produces a very minimal bioload, making it an excellent choice for smaller aquariums or systems nearing capacity. Its diminutive size ensures that it adds almost no significant waste to the water column. Aquarists will find that standard filtration and regular maintenance are more than enough to handle its presence. This low impact allows for a cleaner reef environment without the need for oversized protein skimmers.
- Fluss
- Moderate
- The Ecsenius oculus thrives in moderate to strong water movement, which accurately replicates the dynamic reef crests it naturally inhabits. Strong currents help to continually wash away detritus from its favorite perching areas and rocky crevices. This flow also promotes the healthy growth of the algal films it relies on for sustenance. Be sure to provide some sheltered pockets within the rockwork where it can rest without fighting the current.
- Sprungrisiko
- Yes
- Like most of its relatives, the Ecsenius oculus possesses a significant risk of jumping out of open aquariums. It is prone to leaping when startled by sudden lighting changes, sudden movements outside the tank, or aggressive tank mates. A tightly fitting lid, mesh screen, or canopy is an absolute necessity when keeping this fish. Without proper covering, it is unfortunately common to find this species dried up on the floor.
- Reproduktion
- Oviparous
- The Ecsenius oculus is a benthic egg layer that utilizes small crevices, barnacle shells, or rocky caves for spawning. In the wild, the male diligently guards the clutch of eggs and aggressively defends the nest against potential egg predators. Captive breeding has been documented, though raising the microscopic fry requires advanced planktonic food cultures. For most hobbyists, reproduction in a mixed reef display remains a rare and challenging event.
- Kompatibilität & Tankkameraden
- Peaceful
- This species is remarkably peaceful towards most tank mates, making it a staple for community reef setups. The Ecsenius oculus generally ignores corals and invertebrates, though it may occasionally perch on larger stony corals. It can, however, show severe territorial aggression towards other blennies of similar body shape. Keeping it as the sole benthic grazer in a smaller tank is highly recommended to prevent conflicts.
- Tankfüllstand
- Bottom
- As a true benthic species, the Ecsenius oculus spends the vast majority of its time in the lower portions of the aquarium. It hops or swims in short bursts from rock to rock, rarely venturing into the open upper water column. It will claim specific holes or crevices as its permanent residence, reversing into them tail-first. This bottom-dwelling behavior adds wonderful dimension and activity to the lower strata of the reef.
Wissenschaftliche Modelle & Parameter
FishBase
Zugang zu den offiziellen wissenschaftlichen Daten der Art
FishBase v25.04Daten synchronisiert am: 15.06.2026
- Trophäenniveau
- 2 ± 0 se
- Belastbarkeit
- Hoch (weniger als 15 Monate)
- Phylogenetische Einzigartigkeit (PD50)
- 0.5
- Bayessche Längen-Gewichts-Beziehung
- a = 0.00776, b = 3
- AnfälligkeitGeringe Anfälligkeit (10 / 100)
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