Without a swimming bladder, this bony fish is the heaviest and largest, reaching up to three tons in weight and three meters in diameter. The females hold the record for most number of eggs laid in one time, 300 million eggs, they are tiny compared to its adult size. To become an three metre adult, the larva at birth which measures only 0.25 cm will increase its weight of 60 million times!
The months of May and June are the most likely time to sight this fish, but it is present throughout the year in the waters of Elba and on November 1 2015 an encounter with a large specimen occurred which you can see documented in this movie.
Really Strange Fish
When you come across it, its strikingly unusual shape suggests it is clumsy, slow and somewhat out of place, but in just a moment it quickly moves away using dorsal and ventral fins as if they were wings. Its round shape and gray skin covered with scars and parasites resembles the surface of the moon from which its takes it’s common name of “moonfish”. The scientific name is due to its shape which is reminiscent of the grinding wheel of a mill and hence the name “Mola mola”.
An Annoying Problem
Often spotted on the surface, its dorsal fin is often mistaken for that of a shark even it has an undulating movement. It is not uncommon to see some specimens jumping high of the water to try to get rid of parasites through collisions with the surface, or, for the same reason lying right on the surface of the water to allow the seabirds to clean it up, because of this type of behaviour it is called “sunfish” in English. Usually when sighted underwater, it has approached the coast to be cleaned by small fish such as the green wrasse or the damsel.
It seems to feed mainly on macro plankton (jellyfish, ctenophores and salpa) but algae, crustaceans, molluscs and small fish are regularly found in its stomach, so it can be considered omnivorous.
Very little is known of this fish given the low commercial interest, it belongs to the same order as the trunk fish and like them, its meat can be rich in tetrodotoxin poison that even in small doses can cause paralysis and death in humans.