Ocean Sunfish Mola mola

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Ocean SunfishMola mola
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Taxonomy

• Phylum Chordata
• Subphylum Vertebrata
• Class Actinopterygii
• Division Teleostei
• OrderTetraodontiformes (triggerfish, boxfish,
  porcupine fish, pufferfish)
• Family Molidae
• Genus, Species Mola mola

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Teleost and Tetradontiformes

• Division Teleostei the most dominant living
  fishes
• Teleosts account for 96 of all living fishes
• Order Tetradontiformes the most highly derived
  fishes The pinnacle of teleostean evolution
• Characterized by a high degree of fusion or loss
  of numerous bones in the head and body
• Date back to the early Eocene (55 to 38 million
  years ago)

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http//www.amonline.net.au/fishes/fishfacts/fish/m
ola.htm

• Worlds heaviest bony fish
• Can grow to be 2m long and weigh as much as
  1000kg (2200 pounds)
• The largest mola ever recorded was 2235 kg (4,927
  lbs).
• It measured 3.1 m (10 ft) from snout tip to
  "tail" fin and 4.26 m (14 ft) from dorsal fin to
  anal fin tip

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http//www.groton.k12.ct.us/WWW/fsr/student/spr04/
Jessi/FISH.htm

• Molas have a large number of cartilaginous
  elements or cartilage-lined bones in their skulls
  and in their fin supports.
• The body is essentially rectangular in side view
  with very tall, thin dorsal and anal fins that
  propel the fish
• They lack a true tail but have a pseudocaudal
  tail fin made up primarily of dorsal and anal fin
  rays

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http//cordellbank.noaa.gov/images/wildlife/mola.j
pg
http//www.amonline.net.au/fishes/fishfacts/images
/sunteeth.jpg

• They lack true teeth and instead have tooth
  plates that are shaped like a beak
• Mola mola comes from the latin word millstone
• Their aptly named sunfish because they are
  usually found basking on their sides at the
  surface

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Mola diets

• Mostly pelagic feeders
• Diet consists of jellyfish, Portuguese man-o-war,
  ctenophores and salps.
• Squid, sponges, serpent star bits, eel grass,
  crustaceans, small fishes and deepwater eel
  larvae have also been found in M. mola guts
• Indicating that they forage both at the surface,
  among floating weeds, on the seafloor and into
  deep water

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Reproduction

• Spawning habits unknown
• Capable of producing 300 million eggs, an
  apparent record among fishes
• After hatching, the larvae look more like
  pufferfish. They measure just 2.5 mm
• As they grow the spines disappear, as do their
  tails

http//www.oceansunfish.org/lifehistory.html
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Molas and parasites

• Molas are infamous for their impressive parasite
  load
• Up to 40 genera have been found on one individual
• Could bask on side to let gulls remove parasites

http//www.amonline.net.au/fishes/fishfacts/images
/mmolapar.jpgimgrefurl
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Parasites contd

• Molas have been seen frequenting kelp beds as
  well as other cleaning stations

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Predators

• Large portion of bycatch in Pacific
• Market in Asian culture
• Sea lions
• Orcas
• Parasites

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Molidae evolution

• Highly derived group The most advanced
  tetraodontiforms are the three species of
  temperate and tropical molas (Molidae)
• Molidae has returned anatomically to a starting
  point in fish evolution
• It is therefore important to bring up that
  evolution does not mean moving from primitive to
  advanced forms

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• The molas rediscovery of the utility of
  cartilage underscores the observation that all
  living fishes are the successful result of the
  trial and error processes of mutation and natural
  selection

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The Diversity of Fishes, Helfman G.S., B.B.
Collette, and D.E. Facey, Massachusetts,
Blackwell Science, Inc. 1999http//www.oceansunf
ish.org/lifehistory.html