Pelagic fish
Giant sunfish (bump-head mola)
Mola alexandrini
Mola alexandrini has never been assessed by the IUCN Red List — FishBase records it as Not Evaluated and it does not appear in the Red List checklist — so conservation status is recorded as unknown rather than guessed. Not Evaluated is not a clean bill of health: the closely related Mola mola is assessed as Vulnerable, and the IUCN Molidae review panel flagged the giant sunfish as a priority for a first assessment.
- Max size
- To about 3m and over 2,000kg
- Habitat
- Deep open water; visits shallow reef cleaning stations where cold upwelling reaches the coast
Best places to dive with Giant sunfish (bump-head mola)
| Month | Likelihood |
|---|---|
| January | rare |
| February | rare |
| March | rare |
| April | rare |
| May | rare |
| June | rare |
| July | occasional |
| August | peak season |
| September | peak season |
| October | peak season |
| November | occasional |
| December | occasional |
Present in the area year-round from the surface to well below recreational depth, but divers encounter them mainly between about July/August and November — the locally named sunfish season — when southeast-monsoon upwelling brings cold Indian Ocean water up the southern and western coasts. Crystal Bay is the best-known site, with Blue Corner, Toyapakeh and the north-coast drifts also producing them. Encounters are usually deep and brief, and nothing about them is scheduled.
Sources & last checked
Checked August 2026
Research is source-backed, but conditions and fees should still be confirmed locally.
View 3 sources and checking notes
- Rapid physiological colouration change is a challenge — but not a hindrance — to successful photo identification of giant sunfish (Mola alexandrini, Molidae), Frontiers in Marine Science
- The ocean sunfishes (family Molidae): Recommendations from the IUCN Molidae review panel, Marine Policy (ScienceDirect)
- Upwelling variability along the southern coast of Bali and in Nusa Tenggara waters, Ocean Science Journal
Note on the data: The IUCN Molidae review panel listed Mola alexandrini as awaiting a first Red List assessment; no confirmed published category was found, so conservation status is recorded as unknown rather than guessed.