fresh-water lobe-finned fish

Some lobefin fish {fresh-water lobefin fish} {fresh-water lobe-finned fish} had adults that lived in fresh water and on land.

fresh water

Because fresh water has no salt, they had to maintain hydrogen and salt ion balance in blood and tissues and had to control water drinking. Seawater ion balance is similar to that in cells. To live in fresh water, organisms need to pump out cell water to maintain salt and protein concentrations and to prevent bursting.

hind limb

Rear lobefins became specialized for pushing. Later, they became legs.

teeth

Teeth were for grasping but not cutting or grinding. Teeth grew, fell out, and grew back, repeating as animals grew.

hearing

Eardrum amplified sound for better hearing.

lung

They breathed using lungs. They had no gill bones and began gill loss. Later, gills closed.

evolution

Land vertebrates evolved from lobe-finned bony fish.

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4-Zoology-Kinds-Fish-Teleost-Lobe-Finned-Fresh Water

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Date Modified: 2022.0224