Tuna Fish (Verified ◎)

: They are "obligate ram ventilators," meaning they must swim continuously to force oxygen-rich water over their gills; stopping would lead to suffocation.

: While often found in surface waters, some species can dive deep into the ocean to hunt, with Pacific bluefin tuna known to migrate over 6,000 nautical miles. Commercial Importance and Species Diversity tuna fish

: Their sleek, streamlined bodies and lunate (crescent-shaped) tails allow them to reach bursts of over 40 mph. : They are "obligate ram ventilators," meaning they