I just got back from a quick 5 day trip to San Francisco Bay visiting a friend and 2nd cousin. While I was there, we took a trip to the Monterey Bay Aquarium. If you love the ocean, you really need to make this a destination someday. It’s on the site of a former sardine cannery right on the pacific ocean. In fact, it’s so close to the ocean that the aquarium pumps in water from the bay as part of it’s exhibits.

I learned something really amazing about Tuna and similar fish during the Aquarium Visit. Tuna use a form of propulsion called thunniform swimming. In this type of swimming, the propulsion comes mainly from the tail and very little movement occurs from the fish’s body. As a result, the area just in front of the tail fin has a unique streamlined shape specialized for side to side movement! A small ridge pointed to each side allows the part of the tail that articulates to move left & right while slipping through the water….leaving the large crescent shaped tail fin to propel the fish forward.

Look carefully at this video…it’s short, but notice the narrowing of the body immediately in front of the crescent shaped tail. If you look closely, you’ll see the horizontal ridges in this narrowest part that I’m talking about!

 

 

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