Division Teleostei = "end bone"-- 42 orders; 431 families; 23,681 species

• "main line" of fish evolution

• Caudal fin -- uroneurals at end of vertebral column articulate with fin rays in homocercal tail
• Variation in paired fin position
• Varied feeding ecology
• Evolution of the jaw, sliding premaxilla, rotating maxilla
• Arose during the Mesozoic, ca. 200 mya probably from a Neopterygian ancestor

• Fossil record indicates that boneytongues were dominant freshwater fishes before the appearance of Ostariophysans
• Teeth located on tongue and roof of the mouth (parasphenoid bone of the skull)
• No intramuscular bones on the back, cycloid scales with ornate sculpturing (lepidological character)

• (7 spp.) found in tropical rivers
• Physostomous swim bladder, respiration
• Largest totally freshwater fish Arapaima gigas (up to 3 m)
• Special pouch in mouth to incubate young
• Mostly carnivorous, Western African Heterotis is a filter feeder

• (2 spp.)mooneye, goldeye; Hiodon
• large eye with tapetum lucidum
• Inhabits Mississippi R. drainage, backwaters
• goldeye support a commercial fishery in northern parts of their range

• (8 sp.) featherbacks (refers to feathery dorsal fin); Asia and Africa
• physostomous swim bladder, respiration
• swim with undulations of anal fin
• prey on invertebrates and small fish in the evening

• (ca. 200 spp.) elephantfishes, Africa
• adapted to reservoirs
• weak electric fields for communication, social interactions, localize objects: change the amplitude/frequency of waves, timing of discharges
• largest cerebellum of any fish, body-weight adjusted size is comparable to humans
• engage in play behavior

• Electrocytes or electroplaques -- modified muscle cells (exception: ghost knifefish Apteronotidae uses modified nerve fibers)
• Ion flux across cell membranes produce small electrical current
• Stacked in series to produce large current
• Require considerable coordination by the CNS - pacemaker cells in brain stem (Gymnotids) or midbrain (Mormyrids)
• Strong electric fields generated by electric rays, electric eel (Gymnotiformes), and catfishes-- have 1000's of electrocytes

• Includes tarpons, eels, swallowers, and gulpers
• Reduction in uroneural bones that support tail
• Possess riblike epipleural intramuscular bones
• Leptocephalus larvae
• feeds on organic matter absorbed through the skin!
• Extremely long-lived (2-3 years in some anguillid species)
• Lack RBCs

• Retain remnant gular "splint" on underside of throat
• Incorporate maxilla into the gape
• Possess heavy, bony scales with some ganoine

• Ladyfishes, tenpounders

• Tarpons - highly fecund, large females can produce up to 12 million eggs!

• Loss of pelvic girdle, reduced or absent paired fins
• Greatly reduced or absent scales
• Modified upper jaw formed by fusion of several bones
• Occupy a variety of habitats including deep-water, freshwater streams, pelagic, in- near-shore.

• Catadromous life history
• Important predator in many lakes and streams
• Genus Anguilla

• Moray eels
• Inhabit reefs and rocky shores of tropical, temperate regions
• Lack paired fins
• Ciguatera poisoning from eating moray flesh

• Bathy-, Mesopelagic
• Shallow benthic: resemble moray eels, most feed on invertebrates
• Fossorial: Garden eels, filter feeders, form colonies on sandy bottoms in areas of moderate current
• Facultative parasitism: snubnose parasitic eel.

• Snake and worm eels; tropical and subtropical waters
• Burrow in substrate but only use burrow temporarily; active at night
• Well developed branchial pumping apparatus, anterior and dorsal nostrils

• Highly modified gape - formed by loss of opercular bones, branchiostegals, maxilla, premaxilla (among others)
• Also lost paired fins, ribs, pyloric caeca, and swim bladder
• Some species possess rostral fangs and venom glands
• Some may attract prey with light-producing organ in tail
• Nelson (1994) "perhaps the most highly modified of all vertebrate species"

• Swallowers

• Gulpers

• Otophysic swim bladder - makes contact with the inner ear, increase sensitivity to low frequency sounds (3 - 20 Hz).
• Sharp, bony scutes along the ventral edge
• Among the most abundant vertebrates on Earth
• Provide important trophic links between primary producers and piscivores
• Commercially important in many parts of the world, depend on upwelling currents and algae blooms- boom and bust population cycles

• Red Herring -- [from the practice of drawing a red herring across a trail to confuse hunting dogs] : something that distracts attention from the real issue

• Overhanging snout
• Filter feeders; inshore areas of oceans where plankton densities are high

• Monophyly is debated because unique shared, derived characters common to all members is lacking
• Adipose fin is present
• Epidermal breeding tuburcles

• largest group of freshwater fishes in the world (ca. 6500 spp.)
• Fright substances (Shreckstoff) are present
• Two chambered swim bladder is usually present
• Breeding tuburcles are well-developed with keratinous cap
• Extendable premaxilla for suction feeding
• Pelvic fins are abdominal in position

1. Hiodon alosoides - goldeye (Hiodontidae)
2. Anguilla rostrata - American eel (Anguillidae)
3. Gymnothorax funebris - green moray (Muraenidae)
4. Gymnothorax moringa - spotted moray (Muraenidae)
5. Ophichthus punticeps - palespotted eel (Ophichthidae)
6. Alosa pseudoharengus - alewife (Clupeidae)
7. Dorosoma cepedianum - gizzard shad (Clupeidae)
8. Brevoortia tyrannus - menhaden (Clupeidae)
9. Anchoa hepsetus - striped anchovy (Engraulidae)