Chaetodon robustus
Rare deep-reef butterflyfish best found around São Vicente and Sal in Cape Verde, in warm 24-29C water year-round.
A small, deep-bodied butterflyfish around 9 cm, pale silvery-yellow overall with a dark vertical band running through the eye and a darker patch toward the rear of the body. The snout is short and the fins carry a faint yellow wash, without the bold bars or eyespots seen on many reef butterflyfish. Look for it hugging rock and reef structure well below recreational sport-diving depths, often solitary or in a loose pair.
Divers log this one down deep, typically well past 30 metres, moving slowly over rock and reef ledges rather than schooling in open water. It is generally logged as uncommon rather than a guaranteed sighting, picking through crevices for food and showing little concern for divers who keep their distance.
Its depth range, starting around 30 metres and running to 70, puts it mostly out of reach of standard recreational dives, which is a big part of why it is logged as uncommon even in its Cape Verde stronghold.
No clear season shows up in the sightings, and the water it favours (24.2 to 28.8C) stays within that band year-round across its range, so any month is fair game. Plan around depth and visibility on a given trip rather than a particular season.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Cape Verde is by far the strongest place to find this one, with sightings concentrated in São Vicente, Sal, Santo Antão and Boa Vista. Outside West Africa it turns up occasionally in Western Cuba, Sierra Leone's Banana Islands and off Angola near Luanda, plus scattered records in the United States, Belize, São Tomé and Príncipe and Palau.
Mapping where Ghana Butterflyfish is logged…
Cape Verde is the reliable stronghold, especially São Vicente, Sal, Santo Antão and Boa Vista. Smaller numbers turn up in Western Cuba, Sierra Leone's Banana Islands and Angola near Luanda.
There is no strong seasonal pattern in the sighting data, and its preferred water temperature of roughly 24 to 29C holds steady year-round in its range, so it can turn up on any month's dive.
Look for a small, pale silvery-yellow butterflyfish around 9 cm with a dark vertical band through the eye and a darker rear patch. It lacks the bold stripes of many reef butterflyfish and is usually seen alone on deep rock and reef structure.
They stay small, typically around 9 cm long, in keeping with most butterflyfish species.
It lives deep, between about 30 and 70 metres, which puts it below most recreational dive limits. Even where it occurs, like Cape Verde, it is logged as uncommon rather than a sure thing.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
