Istiblennius zebra
Common on Hawaii's shallow reef edges, this small striped blenny sits in water 22.6-28.6°C and is spotted year-round.
A stubby, tube-shaped fish barely bigger than a finger, topping out around 13 cm, with pale grey-brown skin crossed by narrow dark zebra-style bars. Look for it perched on exposed rock or reef flat rather than swimming in open water, propped on its pectoral fins with big, high-set eyes and a blunt face. It often sits half out of the water in the wash zone, which is usually the giveaway before you even see the stripes clearly.
Found perched on rock and reef flat in the shallow surge zone, often just below or right at the surface where waves wash over it, grazing algae off the rock face. It tends to hold its ground rather than bolt when divers or snorkellers approach, relying on its mottled pattern to blend into the wet rock. Most sightings are in the shallows close to shore rather than out on deeper reef.
Like other rock-skipper blennies it can survive brief spells out of water in the splash zone, using the wet rock surface and residual moisture to keep breathing between wave washes.
Water in its comfort range (22.6 to 28.6°C) holds across the Hawaiian dive season, and there is no detected month-to-month pattern in sightings, so it is a year-round find rather than a seasonal one.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
This one is a Hawaii speciality: essentially every logged sighting comes from Hawaiian sites, making it one of the most reliably found blennies on the islands' shallow reef flats and rocky shorelines. It has not been logged in meaningful numbers anywhere else, so if you want to tick this species, Hawaii is the destination.
Mapping where Zebra Rock Skipper is logged…
It is essentially a Hawaii-only find, logged across shallow reef flats and rocky shorelines throughout the islands. Divers and snorkellers see it far more often there than anywhere else recorded.
There is no strong season logged for this species, and it favours water between 22.6 and 28.6°C, which holds year-round in Hawaii. Expect a fair shot at it on any visit to shallow reef flats.
Look for a small, tube-bodied blenny under 13 cm with narrow pale zebra-like bars, perched on exposed rock in the shallow surge zone rather than swimming freely. Its habit of sitting half out of water is as useful for ID as the stripes.
They max out around 13 cm, making them one of the smaller blennies you will spot perched on shallow Hawaiian reef rock.
No, they pose no threat to divers or snorkellers. They are small herbivorous blennies that hold still on rock rather than react defensively.
It can tolerate short periods stranded out of water in the splash zone, gripping wet rock and surviving on residual moisture between wave washes, a trick shared with other rock-skipper blennies.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Ophioblennius atlanticus
Klipfish
1,860 sites
