What period and age is associated with the age of fishes?

The age of fishes is associated with the Devonian period, and it was part of the Paleozoic era. This is because there were diverse and abundant species that were found in this period. Sometimes the creatures that swam the Devonian seas were bizarre. 

Step-by-step explanation

The period experienced the link between the early amphibians and the lobe-finned fishes. The period occurred around 416 million years ago. It is during this period that the paramount amphibians that were four-legged made appearance, and marine organisms known as ammonites.

About 85% of the Devonian land was covered by the ocean. The changes in the level of the ocean and sea level triggered the extinction of these species. The drop in sea levels was triggered by volcano activity in the ocean and global cooling.