Many people are familiar with the annual growth rings in tree trunks. Most fishes have similar features in their bodies; their bones have alternating bands of dark and translucent tissue that indicate the passage of time. But the skeleton of a shark is made of cartilage, not bone. It turns out that vertebrae of whale sharks have rings like those in fish bones and tree trunks. How long does it take for a new “ring” to grow in whale shark vertebrae? Thanks to the atomic bomb, scientists determined that it takes about one year.
The Marine Science Institute's monthly column, Science and the SeaTM, is an informative and entertaining article that explains many interesting features of the marine environment and the creatures that live there. Science and the SeaTM articles appear monthly in one of Texas' most widely read fishing magazines, Texas Saltwater Fishing, the Port Aransas South Jetty newspaper, the Flour Bluff News, and the Island Moon newspaper. Our article archive is available also on our website.
By the late 1960s, many Americans were getting fed up with bad news about the environment. A book early in the decade warned about the dangers of pesticides. An oil spill on the coast of California killed thousands of birds and other creatures. A river in Ohio caught fire. And pictures snapped by an Apollo astronaut showed Earth as a fragile blue ball.
To inform Americans about the problems, Senator Gaylord Nelson of Wisconsin organized an “environmental sit-in.” It was held on April 22nd, 1970 — the first Earth Day. And an estimated 20 million people took part.
Most people think of great white sharks as the top predator of the sea, and they are among the largest, most ferocious sharks swimming around. But even white sharks fear another predator—possibly a surprising one. Orcas, commonly called killer whales, may seem friendly when performing tricks at some amusement parks, but just their arrival is enough to send white sharks packing.
It’s the question every parent fears: Who is your favorite child? In the case of Magellanic penguins—if their chicks could ask—the answer is the most egalitarian: both of them! Many animals with multiple offspring make tough choices about distributing resources to their brood. Many runts don’t survive because they can’t compete or because their parent must favor those offspring that are most likely to survive and thrive.
Descending several hundred feet toward the twilight zone of the ocean, there’s usually too little light to perceive any colors. Many creatures are visible primarily because of their bioluminescence – the dim, glowing light they produce. But one hardy little fish living on deep reefs in the Indian Ocean has defied the odds.