Pelagic fish
Dogtooth Tuna
Gymnosarda unicolor
A heavy-bodied Indo-Pacific tuna, dark above and silver below, with the conical teeth its name refers to. Unlike most tuna it stays close to reef structure rather than roaming open ocean, which is why divers see it at all. It hangs off the current-facing side of pinnacles and moves through fish schools in fast passes. Common on seamounts with strong flow; scarce where reefs are heavily fished, since it is a prized target species.
- Max size
- Up to about 2.5m and 130kg
- Habitat
- Outer reef slopes, seamounts and current-swept pinnacles across the Indo-Pacific, usually in clear water from the surface to about 100m. Adults are often solitary or in small groups; juveniles school.
Best places to dive with Dogtooth Tuna
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Hang in the flow at Kal's Dream and other pinnacles, hunting the schooling fish that gather in the throughflow.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Dogtooth tuna and rainbow runners pass through the blue water off the pinnacles.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Reported year-round on the current-swept northern sites — Castle Rock and GPS Point are the ones operators name — alongside big trevally and mackerel. Coded occasional rather than resident: sightings track current strength on a given dive more than the calendar, and no seasonal pattern was found in the sources reviewed.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Cruise the deeper walls and pinnacles, especially where current runs, alongside jacks and mackerel; seen on many but not all dives.
Sources & last checked
Checked July 2026
This is a researched draft, not yet human-verified. The seasonality and logistics are drawn from the sources below — confirm specifics (permits, fees, closures) with an operator before you book.