Mola is the type genus of the family Molidae, including marine fish commonly known as ocean sunfish. Mola includes three of the five species within Molidae, as well as one extinct species.[1] Species within Mola are differentiated from the other species within Molidae by their larger size in comparison to the other two members of the family. In Latin, the name "Mola" means "millstone", referencing the round, flat shape of ocean sunfish. This genus includes the heaviest of all living bony fishes, Mola alexandrini.[2][3]
| Mola Temporal range: | |
|---|---|
 | |
| Mola mola | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Tetraodontiformes |
| Family: | Molidae |
| Genus: | Mola Linck, 1790[5] |
Description
editThis section may require copy editing for grammar, style, cohesion, tone, or spelling. (March 2026) |
Molas develop their truncated, bullet-like shape because of their tail fin, which is present at birth. The tail fin never grows, but it folds into itself as the fish matures, which creates a rounded rudder called a clavus.[6] Mola in Latin means "millstone" and describes the ocean sunfish's somewhat circular and flattened shape.[7][8] They are a silvery colour and have a rough skin texture.[9]
Molas are the heaviest of all the extant bony fishes: large specimens reach 4.3 m (14 ft) vertically and 3 m (10 ft) horizontally, and can weigh over 2,700 kg (6,000 lbs).[10]
Molas inhabit temperate and tropical oceans around the world.[7] They are frequently seen basking in the sun near the surface and are often mistaken for sharks when their huge dorsal fins emerge above the water. Their teeth are fused into a beak-like structure, and they are unable to fully close their relatively small mouths.[11]
Ocean sunfish can become infested with skin parasites, so they often invite small fish or even birds to feed on them.[12] Sunfish sometimes breach the surface up to 3 m (10 ft) in the air in an attempt to shake off parasites.[13]
Their food of choice is jellyfish, though they will eat small fish and large amounts of gelatinous zooplankton and algae as well.[7] They are harmless to people, but can be very curious and will often approach divers.[14]
Their population is considered vulnerable,[15] as they are frequently snagged in drift gill nets and can suffocate on plastic bags, which resemble jellyfish, their main food source.[16]
They breed by producing around 300 million eggs directly into the ocean (spawning), which are externally fertilized by sperm into the water column.[17]
Taxonomy
editIn 1766, Joseph Kölreuter published a fish name Mola but did not treat it as a Linnaean genus (i.e. not binomial), so the name is invalid under the rules of the ICZN. The first author who used the name Mola as a valid genus was Johann Heinrich Linck the Younger in 1790. Mola is therefore the oldest available name, with the basionym Tetraodon mola Linnaeus, 1758 as its type species.[18]
Species
editThe genus was considered monotypic for several decades, but modern taxonomic work revalidated one species and described another; the following species are currently recognized within this genus:[19][20]
- Mola mola (Linnaeus, 1758) (Ocean sunfish)
- Mola alexandrini (Giglioli, 1883) (Southern sunfish)
- Mola tecta Nyegaard et al., 2017 (Hoodwinker sunfish)
- †Mola pileata (extinct), Upper Miocene to Middle Miocene
The following cladogram is based on a 2017 study of mitochondrial D-loop sequences and its maximum likelihood phylogenetic tree:[20]
| Mola | |
References
edit- ↑ "Evolution | Ocean Sunfish". Retrieved 2026-05-03.
- ↑ Sawai, Etsuro; Nyegaard, Marianne (June 2022). "A review of giants: Examining the species identities of the world's heaviest extant bony fishes (ocean sunfishes, family Molidae)". Journal of Fish Biology. 100 (6): 1345–1364. Bibcode:2022JFBio.100.1345S. doi:10.1111/jfb.15039. ISSN 1095-8649. PMID 35289924.
- ↑ "Species and Distribution | Ocean Sunfish". Retrieved 2026-05-03.
- ↑ Sepkoski, J. (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology. 364: 560. Archived from the original on 2011-12-07. Retrieved 2026-05-01.
- ↑ Welter-Schultes, F.W., V. Feuerstein (2008) Nomenclatural notes on Torpedo (Chondrichthyes: Torpedinidae) and some other early established fish taxa (Actinopterygii: Molidae, Eleginopidae and Citharinidae). Species, Phylogeny and Evolution 1(3):141-145.
- ↑ "Ocean Sunfish (Mola)". National Geographic. Animals. National Geographic Society. 2010-11-11. Retrieved 2026-05-01.
- 1 2 3 "Mola mola (Ocean sunfish)". FishBase. Retrieved 2026-05-01.
- ↑ Eschmeyer, William N. (2016). The Diversity of Fishes: Biology, Evolution, and Ecology (2nd ed.). Wiley-Blackwell.
- ↑ Yoshita, T. (2009). "Morphological studies on the ocean sunfish, Mola mola". Ichthyological Research. 56: 162–172. doi:10.1007/s10228-008-0071-5 (inactive 9 May 2026).
{{cite journal}}: CS1 maint: DOI inactive as of May 2026 (link) - ↑ Cartamil, D. (2011). "Ocean sunfish in the eastern Pacific: distribution, biology and ecology". Journal of Experimental Marine Biology and Ecology. 398 (1): 47–53. doi:10.1016/j.jembe.2010.12.017 (inactive 9 May 2026).
{{cite journal}}: CS1 maint: DOI inactive as of May 2026 (link) - ↑ Fraser-Brunner, A. (1951). "The ocean sunfishes (Family Molidae)". Bulletin of the British Museum (Natural History), Zoology. 1 (6): 87–121.
- ↑ Nakatsubo, T. (2007). "Cleaning symbiosis of the ocean sunfish Mola mola by the albatross Diomedea spp". Marine Biology. 150: 731–736. doi:10.1007/s00227-006-0384-4 (inactive 9 May 2026).
{{cite journal}}: CS1 maint: DOI inactive as of May 2026 (link) - ↑ "Sunfish Breaching". Natural History Museum (London). 2018-06-05. Retrieved 26 August 2025.
- ↑ "Ocean Sunfish Fact Sheet". NOAA. Retrieved 26 August 2025.
- ↑ Liu, J.; Zapfe, G.; Shao, K.-T.; Leis, J.L.; Matsuura, K.; Hardy, G.; Liu, M.; Robertson, R.; Tyler, J. (2016) [errata version of 2015 assessment]. "Mola mola". IUCN Red List of Threatened Species. 2015 e.T190422A97667070. Retrieved 24 September 2025.
- ↑ Pope, E. C. (2010). "The biology and conservation of the ocean sunfish Mola mola: a review". Reviews in Fish Biology and Fisheries. 20: 471–487. doi:10.1007/s11160-009-9130-4 (inactive 9 May 2026).
{{cite journal}}: CS1 maint: DOI inactive as of May 2026 (link) - ↑ "Ocean Sunfish". Oceana. Retrieved 2025-09-11.
- ↑ Fraser-Brunner, A. (1951). "The ocean sunfishes (Family Molidae)". Bulletin of the British Museum (Natural History), Zoology. 1 (6): 87–121.
- ↑ Matsuura, K (2014). "Taxonomy and systematics of tetraodontiform fishes: a review focusing primarily on progress in the period from 1980 to 2014". Ichthyological Research. 62 (1): 72–113. Bibcode:2015IchtR..62...72M. doi:10.1007/s10228-014-0444-5.
- 1 2 Nyegaard, Marianne; Sawai, Etsuro; Gemmell, Neil; Gillum, Joanne; Loneragan, Neil R.; Yamanoue, Yusuke; Stewart, Andrew L. (2018). "Hiding in broad daylight: molecular and morphological data reveal a new ocean sunfish species (Tetraodontiformes: Molidae) that has eluded recognition". Zoological Journal of the Linnean Society. 182 (3). The Linnean Society of London, Zoological Journal of the Linnean Society: 631–658. doi:10.1093/zoolinnean/zlx040. Archived from the original on 22 March 2019. Retrieved 2026-05-01.