Parma alboscapularis
Dark, territorial damselfish patrolling North Island, New Zealand reefs from 5-40m in cool 17-22C water, year-round.
Dark brown to blackish body around 15 cm long, with a stocky, oval damselfish shape and a pale, whitish patch across the upper shoulder that stands out against the otherwise dark flanks. Fins are dusky and blend into the body colour, giving a solid, almost silhouette-like look in open water. That shoulder patch is the quickest cue when it is hovering over reef in low light.
Expect to find it holding a patch of reef rather than roaming, often hovering just off the rock face or tucked near a ledge between 5 and 40 metres. It is not particularly shy around divers and will usually stay put or make short darting moves back to its territory rather than bolting, which makes it an easy, unhurried subject to watch or photograph.
As a herbivore, it likely spends much of its time grazing algae off the reef surface within its patch, a role that helps keep that turf in check much like other territorial damselfish do on reefs worldwide.
Sightings show no clear seasonal pattern, and with a comfortable range of 16.8 to 22.1C it seems to hold territory on North Island reefs across the year rather than migrating in and out with the seasons.
This is a North Island, New Zealand fish through and through, with logged sightings concentrated across dive sites there and nowhere else in the current data. If you are diving the North Island's temperate reefs, it is one of the more dependable damselfish to tick off, ranging from uncommon to very common depending on the site.
Mapping where Black Scalyfin is logged…
It is logged almost exclusively around the North Island of New Zealand, where it turns up on a wide range of dive sites from uncommon to very common depending on location.
There is no strong seasonal signal in sightings, so it appears to be present year-round on North Island reefs, consistent with its tolerance for a fairly wide 16.8 to 22.1C temperature range.
Look for a dark brown to black damselfish about 15 cm long with a pale whitish patch across the shoulder area. It has a stocky oval shape and tends to hover close to reef structure rather than swim far into open water.
They typically reach around 15 cm in length, a modest, solidly built size typical of reef-associated damselfish.
No, they pose no danger to divers. They are herbivorous, territorial reef fish that may approach out of curiosity or to defend their patch but will not threaten a diver.
They are herbivores, grazing algae from rock and reef surfaces within their home territory, a behaviour typical of damselfish that helps shape algal turf on the reef.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Yellowtail Clownfish
3,523 sites
