Predict how a fish's behavior would change if it had an open circulatory system instead of a closed circulatory system

Since the blood does not return to the heart after flowing through the gills, pressure is not regenerated within the system before it flows to the systemic circulation (the rest of the body). A single circulation would experience a loss of pressure after flowing through the gas change organs (gills of a fish) due to the high cross-sectional area presented by the capillaries of the gills. For ectotherms like fish, this is efficient enough to support their activity level. A fishes behavior would change in a few ways if it had an open circulatory system. However, the most common would be the fish would become extremely active.

i think the answer is

mass

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?