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3966 Bony Fishes

MOLIDAE Molas (ocean sunfishes) by J.B. Hutchins iagnostic characters: Moderate to large fishes D(to 3 m or more); body short and deep or dorsal fin oblong, prominently compressed; caudal pedun- cle and typical caudal fin absent.Eyessmall. Mouth terminal, small; teeth united and beak-like in pseudo-caudal fin each jaw without a median suture; no palatine teeth. or clavus Gill opening small, pore-like, located in front of pectoral-fin base. Dorsal and anal fins of similar shape, generally triangular, dorsal fin located opposite anal fin; dorsal and anal fins spineless, each with 15 to 21 soft rays; pectoral fins small to moderate sized, located midlaterally, fitting into a shallow concavity in side of body, or concavity ab- sent; pelvic fins absent; caudal fin replaced by a leathery, rudder-like lobe known as a pseudo- caudal fin or clavus (supported mostly by fin-ray elements originally belonging to dorsal and anal fins). Skin leathery, with many small scales (small juveniles may also have some larger scattered spiny gill opening scales). Colour: base colour variable, ranging from grey, brown, purplish brown, greyish blue, silvery, to white, sometimes with either pale or dark spots. Habitat, biology, and fisheries: Pelagic fishes of tropical and temperate oceans, infrequently entering harbours. Sometimes seen swimming lazily, or idling at the surface, often partially on their sides. They are occasionally beached during storms. Food consists of jellyfishes, salps, ctenophores, larval eels, and at times other fishes. Usually heavily parasitized. Not anal fin generally eaten as flesh considered tough and unpal- atable. However, in some parts of the world, they are treated as a delicacy.

Similar families occurring in the area None. The peculiar truncated shape, absence of a caudal peduncle and a normal caudal fin, together with the high dorsal and anal fins located far posteriorly on body readily distinguish these fishes from all other families.

Key to the species of Molidae occurring in the area 1a. Body moderately deep, more or less oblong in lateral profile, body depth approximately 2 times in body length; lips funnel-like, closing as a vertical slit; skin smooth; pectoral fins elongate, fitting into shallow groove in side of body ...... Ranzania laevis 1b. Body very deep, oval or almost circular in lateral profile, body depth 1 to 1.5 times in body length; lips not funnel-like, closing in roundish form; skin with rough texture; pectoral fin small and rounded, not fitting into shallow groove in side of body ...... ® 2

2a. Clavus (pseudo-caudal fin) with a distinct median extension (very long in juveniles, noticeably shorter in adults), remaining margin not scalloped ...... Masturus lanceolatus 2b. Clavus without a distinct median extension, margin mostly scalloped ...... ® 3

3a. Clavus supported by about 12 fin rays, of which 8 or 9 bear ossicles; ossicles widely separated, less broad than spaces between them ...... Mola mola 3b. Clavus supported by about 16 fin rays, of which 12 bear ossicles; ossicles close together, much broader than spaces between them ...... Mola ramsayi Tetraodontiformes: Molidae 3967

List of species occurring in the area The symbol 0 is given when species accounts are included. 0 Masturus lanceolatus (Liénard, 1840) 0 Mola mola (Linnaeus, 1758) 0 Mola ramsayi (Giglioli, 1883) 0 Ranzania laevis (Pennant, 1776) Reference Heemstra, P.C. 1986. Family Molidae. In Smith’s sea fishes, edited by M.M. Smith and P.C. Heemstra. Johannesburg, Macmillan South Africa, pp. 907-908.

Masturus lanceolatus (Liénard, 1840) En - Point-tailed sunfish. Maximum total length at least 3 m. Little is known about the exact distribution of this rare species, but it probably occurs in all temperate and tropical seas of the world.

Mola mola (Linnaeus, 1758) En - Ocean sunfish. Maximum total length at least 3.3 m. Found in all tropical and temperate seas of the world, preferring areas well offshore. 3968 Bony Fishes

Mola ramsayi (Giglioli, 1883) En - Short ocean sunfish. Maximum total length at least 3 m. The distribution of this species is uncertain, but it probably occurs in temperate and tropical seas of the southern hemisphere.

Ranzania laevis (Pennant, 1776) En - Slender mola; Fr - Ranzania; Sp - Ranzania. Maximum total length 90 cm. Found in tropical and temperate seas of the world, preferring areas well offshore. Unlike other ocean sunfishes, this species may travel in schools of up to 50 individuals. These schools sometimes become stranded in shallow coastal bays.

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