• Flatfishes
• Triggerfishes, boxfishes, puffers, molas

• Juvenile and adult forms asymmetrical -- larvae bilaterally symmetrical
• Metamorphosis occurs between 4 to 120 mm over about a 5 day period
• Bones incompletely ossified
• Anterior neurocranium, brain, and eyesockets rotate
• Semicircular canals rotate 90^o, lateral line sometimes absent from bottom side
• Swim bladder reduced or absent in adults
• Migration of eyes can be dextral (right-eyed), or sinistral (left-eyed); some species polymorphic (starry flounders -- Pleuronectidae)

• Eggs and larvae pelagic, juveniles and adults benthic (remain close to bottom even while swimming -- fins may aid in this swimming style)
• Secretive in behavior, cryptically colored
• Near shore, in shore habitats universally: many species coexist -- segregration by depth, salinity gradients
• Feeding ecology ranges from mollusk eaters to piscivores; mouth position, premaxillar and pharyngeal dentition is associated with diet
• Many species support important fisheries
• Body length can exceed 3 m (Atlantic halibut), egg production 2 million

Family Bothidae -- left-eye flounders

Family Pleuronectidae -- right-eye flounders

Family Soleidae -- true soles

• Boneless filets, delicate, retain flavor for days

Family Cynoglossidae -- tonguefishes

• Occur at a remarkable variety of depths from shallow water to 1900 m
• Some species have invaded rivers

• Body shape varies from globular to triangular to extremely compressed
• Name refers to common pattern of four teeth (formed from fusion of ancient teeth)
• Loss of pelvic fin and girdle (Balistidae, Tetraondontidae, Molidae)
• High degree of fusion and loss of bones in head and body; reduction in vertebrae, hyomandibular firmly attached to skull, maxilla and premaxilla fused
• Large jaw musculature, pharyngeal dentition stout
• Secondarily evolved bony armor

• Locomation varies from balistiform to ostraciform
• Feed on molluscs, sponges, sea-urchins, corals and jellyfishes (Molidae) -- usually unavailable to other fishes. Other species are predators, zooplankton feeders
• Many species have poisonous flesh -- tetrodotoxin (TTX)
• Most potent non-protein poison known; acts on nervous system
• Concentrated in ovaries, liver, kidney (highest concentrations prior to spawning)

Family Balistidae -- triggerfishes

• Hawaiian name humuhumu nukunuku apua'a literally translates to "fish that sews with a needle and grunts like a pig"
• Sound production by grinding of teeth or vibration of swim bladder
• Have stout 1st dorsal spine, with second spine forming interlocking "trigger"
• Can rotate eyes independently
• Balistiform locomation
• Nippers, browsers, and scrapers on coral reef

Family Monacanthidae -- filefishes -- closely related to triggerfishes

Family Ostraciidae -- boxfishes

• Entire body except fins encased in a bony box (x.s. triangular or rectangular)
• Some species discharge toxin when handled

Families Tetraondontidae, Diodontidae, -- pufferfishes, burrfishes

• Distinguished by the number of bony plates in jaw

Family Molidae -- ocean sunfishes (3 spp.)

• Possess fused teeth in jaw, like other members of the order
• Reversal to cartilaginous elements in skull, fin supports
• No spiny dorsal fin, pseudocaudal tail (made of dorsal and anal fin rays)
• No bony plates in skin; however skin is thick and dense (like cartilage)
• Drift in open water, known to leap out of the water on occasion
• Body size up to 2 m long and 1000kg; high fecundity (300 million eggs)
• Eat jellyfish and squid

Douglas et al. 1999. Did vicariance mold phenotypes of western North-American cyprinids? Evidence from Gila river cyprinids. Evolution 53(1):238-246

Mayden, R.L. 1988. Vicariance biogeography, parsimony, and evolution in North American freshwater fishes. Systematic Zoology 37(4):329-355.

1. Family Paralichthyidae - spotted whiff
2. Family Paralichthyidae - Pacific sanddab
3. Family Cynoglossidae - blackcheek tonguefish
4. Family Bothidae - windowpane
5. Family Bothidae - dusky flounder
6. Family Bothidae - peacock flounder
7. Family Pleuronectidae - starry flounder
8. Family Pleuronectidae - rock sole
9. Family Pleuronectidae - curlfin sole
10. Family Soleidae - lined sole
11. Family Monacanthidae - orangespotted filefish
12. Family Monacanthidae - fringed filefish
13. Family Monacanthidae - dotterel filefish
14. Family Balistidae - Sargassum triggerfish
15. Family Ostraciidae - scrawled cowfish
16. Family Tetraondontidae - sharpnose puffer
17. Family Diondontidae - web burrfish
18. Family Diondontidae - striped burrfish
19. Family Diondontidae - balloonfish
20. Family Molidae - ocean sunfish