3. Write a one sentence description on the function of the following fish adaptations:?

Question

a.Fins

b.Scales

c.Swin bladder

I need this info asap. Thanx

Answer 1

1. Fins are used for balance and movement in the water.

2. Scales afford protection from dehydration and predators and help streamline the fishes' body.

3. The swim bladder helps the fish float at different levels of the water.

Answer 2

The Sentence:

The fossil record confirms that the fins of fish evolved into feet, the scales possibly evolved into teeth, and the swim bladder evolved into lungs.  

The Support:

Actually, this evolution took a very long time and basically occurred during the Devonian period approximately 400 mya.  As the fish moved through the water, and as water levels were dropping at the time, the smaller fish moved into the shallows to avoid the large predators.  Therein they moved along the bottom using their fins for propulsion in search of food.  These fins ultimately developed into feet, i.e., it was a spiny flexible like fan structure at first.  Additionally, because they were near the edge of the land, they found an additional food source, e.g. insects.  That prompted the creature to hover near the water surface and the land for longer periods of time.  

Given that they were also being hunted (for millions of years), by other water dwelling fish, they had earlier developed scales making it more difficult for a larger fish to swallow them.  Especially head on.  

The swim bladder of course allowed for buoyancy and an additional oxygen tank for remaining under water for longer periods.

About 375mya the fish, after the above developments and after living in the shallows for a long time, moved onto land.  The fins became the feet (see Prof. Shubin's new book The Inner Fish), so that they, now called tetrapods, could harvest the creatures on the land (they had two sources of food, both in the water and on the land (fish in the water, bugs and plants on the land)).  

The scales were now no longer necessary as there were no predators on the land save for the new tetrapods, so, this structure (scales) moved forward from around the head and became teeth.  Teeth were very good things to have for catching small bugs (actually some of the bugs were rather large).  

Then, because the tetrapods could live in the water and on the land, the gills receded and the lungs evolved from the swim bladder.  The lungs had become necessary because of the new oxygen rich environment.  The tetrapods had both types of breathing apparatus, lungs (swim bladder allowed animal to move up and down in the water (and stay under for a long period of time) and near to the surface for food, e.g., bugs and leaves floating on the water) and gills for remaining underwater searching for small fish.  Eventually the gills receded and became the inner ear and the swim bladder evolved into lungs.