Breeding season can be brutal — even bloody — for male elephant seals. These heavyweights take the competition for mates very seriously, with both vocal and physical threats to other males. Sometimes they rear up to show their height, and sometimes they slam their chests onto the sand to send intimidating vibrations into the ground. But despite all this posturing, actual physical fights occur less than five percent of the time in elephant seal colonies.
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 newsletter of the Texas Chapter of the American Shore & Beach Preservation Association , and the Heartland Of America online newspaper. Our article archive is available also on our website.
If a species on the brink of extinction could learn to clone itself, that nifty trick could improve its chances for survival. And that’s exactly what scientists have discovered some smalltooth sawfish are doing in Florida — reproducing without mating. This critically endangered species is one of five species of sawfish, creatures that look like a cross between a shark, a ray and a chainsaw blade. Sawfish have a long, flat snout with widely spaced teeth that protrude in a line on either side, an arrangement that is reminiscent of a saw.
You might think the largest – and perhaps loudest – animal ever to roam the planet would not be hard to track. After all, blue whales can grow up to 100 feet long, weigh up to 200 tons and produce sounds that travel 1,000 miles. And yet, until recently, scientists had difficulty figuring out where these massive krill-eating creatures traveled. Now, a single female named Isabela has offered some clues.
Imagine that every time a veterinarian microchipped a dog or cat, the animal found a way to expel the microchip from its body. It turns out that is exactly what a sea star (aka starfish) does with a foreign object in its body. It pushes the object to the tip of an arm and then ejects it from its body.
Shortly after sea turtles hatch and enter the waves, they vanish from sight for the next two to ten years. Scientists often call these the “lost years” because no one is sure where the turtle toddlers go during this time. Until recently, many marine scientists believed the young turtles ride the waves until they gain the strength or navigation skills to actively swim. But scientists wanted to find out for sure, especially since sea turtles are endangered. Knowing where they are going and how they are getting there might make it easier to protect them.
The white vase-like sea sponge known as the Venus flower basket would seem incredibly fragile since it’s made of silica, the main ingredient of glass. Further, the only thing keeping this glass sponge anchored to the sea floor is a tuft of tiny glass structures called spicules, each about the thickness of a human hair.
As utterly exhausting as it is to care for a newborn, most moms would never dream of abandoning their child. But what if it were a question of life and death…for the baby or the mom? That’s the dilemma that sea otter moms sometimes face when they can’t provide enough calories to meet their pups’ incredibly high energy demands. Researchers at a sea otter pup rehabilitation program measured the metabolic rates and daily caloric needs of sea otter pups and found the mothers need to provide more than 222,000 Calories to raise pups from birth to independence.
Just under a million years ago, a major pattern in Earth’s climate suddenly changed. Instead of having an ice age about every 41,000 years, the cycle switched to about every 100,000 years – and the cold periods had even lower average temperatures than the previous ones. What caused the interval between ice ages to double?