Question

You place a fish in a tank with fast flowing water so the fish has to swim ""upstream"" very hard in order to maintain its position. Many species of fish will die under this challenge. What's a major limitation of the fish circulatory system that might cause the fish to die?

Answer 1

Answer:

The fish is likely to suffer a heart attack.

Explanation:

A fish has a single circulatory system, where the blood only flows through the heart once per cycle. The heart receives deoxygenated blood, also called O2 Poor-blood, then it's pumped to the gills, and rest of the body.

Since the fish is under extreme pressure having to swim upwards for an extended period, the blood reaching his heart will have too little oxygen and the muscle will eventually fail.