Answer:
An organism change itself in response to the surrounding environmental condition.
Explanation:
Since striped fishes are able to save themselves from the predators due to their natural ability , the solid fishes would be an easy prey to the predators. This would lead to reduction in the number of solid fishes. Also the sea weed started dying because of environmental change. Thus, predators would shift their feeding pattern from sea weed to easily identifiable fish that is the solid fish and hence the solid fish may deplete rapidly.
Also the striped fishes in later stages may undergo natural selection to prevent themselves from the predators.