Bony fishesWalter Salzburger:

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. 215

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Life

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‣ 73% of the Earth’s surface is covered by water

‣ yet, only 0.01 % vol. of water is found in rivers and lakes

‣ 40 % of all bony fishes are found in freshwater

Fisheries and aquaculture (worldwide), in million tons

Morphology & locomotionw

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tuna

salmon

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rpho

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omMusculature

Locomotion

‣ anguilliform, e.g. eel

‣ carangiform, e.g. trout

‣ ostraciiform, e.g. boxfish

Pough et al. “Vertebrate Life” (1999)

undulating oscillating

Locomotion

Pough et al. “Vertebrate Life” (1999)

Feeding

cichlid(Serranochromis)

“suction-feeding”

Pough et al. “Vertebrate Life” (1999)

Buoyancy

‣ streamline shape and constant swimming (e.g. sturgeon, tuna)

‣ in sharks (cartilaginous fish, Chondrichthyes): also lipid layers

‣ buoyancy via swim bladder

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swim bladder

‣ internal, gas-filled buoyancy organ (oxygen; sometimes also carbon dioxide)

‣ in teleosts and chondrosts

‣ homologous to the tetrapod lung

‣ active regulation of gas pressure via Rete mirabile (‘Wundernetz’) in the gas gland

‣ in bottom dwelling fish: reduction of swim bladders

Swim bladder

real swim bladder (Chondrostei, Teleostei)

pulmonoid swim bladder (Ginglymodi, Halecomorphi)

lung (Dipnoi)

lung (Polypteridae)

lung (Tetrapod)

Swim bladder

physostome swim bladder (e.g. eel) physoclist swim bladder (e.g. perch)

Ductus pneumaticus

Swim bladder

Rete mirabile

lateral line

sensory organs

Pou

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Life

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999)

“electric fish”

electric organ

electric signalsin mormyrids

electric organ

‣ relative simple circulation system

‣ venous blood is transported from the heart to the gills, and from there into the body

circulation

ventral Aorta heart

veinartery

gillgutliver

swim bladder

heart:

‣ relative simple two-chamber-heart with thin-walled atrium and thick-walled ventricle

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Sinus venosus Atrium

ventricle

Bulbus arteriosus

circulation

gills

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gills

gills

gills

gills

countercurrent

Forelle (20g) bei 8˚C

gills

O2-balanceO2-

cont

ent

distance

water

blood

gills

countercurrent