3 trends in vertebrate evolution among fish?

1. Increasing complexity of the brain and nervous system. The brains of fish have become increasingly complex over time, with the addition of new structures and the expansion of existing ones. This has allowed fish to develop new behaviors and abilities, such as learning, memory, and problem-solving.

2. Increased mobility and efficiency of movement. Fish have evolved a variety of adaptations that have allowed them to become more mobile and efficient in their movements. These adaptations include the development of fins, the streamlining of the body, and the reduction of drag.

3. Increased diversity of body forms and adaptations. Fish have evolved a wide variety of body forms and adaptations that have allowed them to occupy a wide range of habitats. These adaptations include the development of different types of fins, scales, and body shapes.