A sunfish, also called a mola, is any

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Mola'' (

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Molidae). The fish develop their truncated, bullet-like shape because the back fin, which is present at birth, never grows. Instead, it folds into itself as the creature matures, creating a rounded rudder called a clavus. ''Mola'' in Latin means "millstone" and describes the ocean sunfish's somewhat circular shape. They are a silvery color and have a rough skin texture. The mola is the heaviest of all the

bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...

, with large specimens reaching vertically and horizontally, and weighing over .

Shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

s and rays can be heavier, but they are cartilaginous fish. Mola are found in temperate and tropical oceans around the world. 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. Ocean sunfish can become infested with skin

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s, so they will often invite small fish or even birds to feast on them. Sunfish will even breach the surface up to in the air, in an attempt to shake off the parasites. They are clumsy swimmers , waggling their large dorsal and anal fins to move, and steering with their clavus. Their food of choice is

jellyfish Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animal ...

, though they will eat small fish and huge amounts of zooplankton and

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

, as well. They are harmless to people, but can be very curious and will often approach divers. Their population is considered vulnerable, as they frequently are snagged in drift gill nets and can suffocate on sea trash, like

plastic bag A plastic bag, poly bag, or pouch is a type of container made of thin, flexible, plastic film, nonwoven fabric, or plastic textile. Plastic bags are used for containing and transporting goods such as foods, produce, Powder (substance), powders, ...

s (which resemble jellyfish, their main food source).

Taxonomy

Kölreuter in 1766 published a fish name ''Mola'' but did not treat is as a Linnaean genus (i.e., not binominal), so the name is unavailable under the rules of the ICZN and cannot be used.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. The first author who used the name ''Mola'' as a genus name was Linck in 1790, and this is therefore the oldest available name, with '' Tetraodon mola'' Linnaeus, 1758 as its type species.

Species

There are currently 3 recognized extant species in this genus: * '' Mola mola'' (

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

, 1758) (Ocean sunfish) * '' Mola alexandrini'' ( Giglioli, 1883) (Southern sunfish) * '' Mola tecta'' Nyegaard ''et al''., 2017 (Hoodwinker sunfish) * †'' Mola pileata'' (extinct),

Upper Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene Epoch made up of two stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million years ago) to 5.333 Ma. The ...

Middle miocene The Middle Miocene is a sub-epoch of the Miocene epoch (geology), epoch made up of two Stage (stratigraphy), stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0. ...

References

{{Authority control Extant Miocene first appearances Marine fish genera