Tuna- The Superfish

Most people think of tuna as just some fish in a can that is an ingredient in tuna salad.  They don’t appreciate what a spectacular animal it is.  Biology books state that fish are cold-blooded, but tuna are an exception to this rule.  Tuna are actually a warm-blooded fish, and this physiology enables them to swim at ultra high speeds of up to 47 mph.  That is faster than most boats.  However, their warm-blooded physiology has a greater temperature range than those of mammals and birds.  Their blood temperatures do vary, while mammal and bird temperatures generally stay constant, unless they are sick.  The video below shows off the impressive speed of this animal.  They swim with dolphins for protection against sharks, explaining why dolphins can get caught in nets intended for tuna.

 

Tuna are large predatory fish that can swim up to 47 mph.

There are 15 species of tuna within 5 genera including the Allothonnus (thunder tunas), the Auxil (frigate tunas), Euthynnus (little tunas), Katsunnus (skipjacks), and Thunnus (true tunas).  Bonitos are considered a sister species to the tunas, and both are part of the mackerel sub-group.  4 species of tuna overwhelmingly make up the tuna found in supermarket cans and at fish markets and sushi restaurants.  These include bluefin, yellowfin, skipjack, and albacore.

Tuna did not become a popular food fish until well into the 20th century, but now every grocery store in the U.S. stocks tuna.  It doesn’t seem likely to me that this can go on forever.  Eventually, wild tuna populations will become too depleted to support this fishery.  The future of tuna remaining a staple in our diet is aquaculture, but tuna fish farming is in its infancy.  Some Japanese have had experimental tuna fish farms for decades, but the 1st tuna farm in America just opened business last year in San Diego.  Tuna fish farming, unlike tilapia, catfish, and salmon aquaculture, has a long way to go.

There is evidence from Indonesia that humans caught tuna as early as 42,000 years ago. (See: https://markgelbart.wordpress.com/2011/12/07/deep-sea-fishing-42000-bp/ ) It’s surprising some primitive people had deep sea fishing technology that early, though tuna swam closer to shore during the Pleistocene because land extended over the continental shelf and deep waters were located closer to the coast then.

The most common species of tuna found in a can–albacore.

500 pound tuna are worth over 3 million dollars to sushi chefs.

1 of my favorite summer dishes is tuna noodle salad and it is very easy to make. Mix a 12 oz package of tuna with the juice of a lemon.  Add a 16 oz box of cooked macaroni, mayo to taste, a can of peas, chopped celery, chopped Vidalia onion, and couple of chopped hard boiled eggs. Stir it up and serve it warm or cold from the refrigerator.

This is my tuna noodle salad.  It’s great warm or straight out of the refrigerator on a hot summer’s day.