Distribution:
Worldwide, in the tropical and subtropical Atlantic, Indian and Pacific Oceans.
Habitat:
Epipelagic or neretic.
Remarks:
The Latin mola or "millstone" refers to the shape of these fishes. Molas have rectangular profiles and very tall dorsal and anal fins, their primary means of locomotion. Molas lack a true caudal fine, but instead have a pseudocaudal or "clavus," formed by modified elements of the dorsal and anal fins. They have small mouths, with two beak-like teeth in the jaws. The dorsal and anal fins lack spines, and the lateral line, swim bladder, and pelvic fins are absent. They have a large number of cartilaginous elements in their skeletons.
Their skin is leathery and thick, often grey above and pale below, and is capable of color change, particularly when under stress (usually from light to dark).
Molas are slow-moving, epipelagic fishes. They feed largely on jellyfishes, also consuming salps, ctenophores, other plankton, algae, and occasionally small fishes. They sometimes move inshore, apparently to have parasites removed by cleanerfishes.
Molas reach a maximum length of over 3 m, and can weigh up to 1000 kg.
The family is comprised of three genera and four species.
References:
Helfman et al. 1997;
Hutchins, pp. 3966-3968, in: Carpenter & Niem 2001;
Nelson 2006