Pelagic fish
Giant sunfish (bump-head mola)
Mola alexandrini
A heavy-bodied mola distinguished from Mola mola by a head bump, a chin bump and a smoother, scalloped clavus. The sunfish at Nusa Penida were long called Mola mola locally, but morphological and genetic work identified them as Mola alexandrini, and images previously reported as Mola mola were re-examined and reidentified. Individuals can be told apart by their body patterns, which underpins the Bali photo-ID catalogue.
- 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 | peak season |
| August | peak season |
| September | peak season |
| October | peak season |
| November | occasional |
| December | rare |
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
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.
- 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.