Walking sharks are only a small piece of our planet’s shark universe, but they’re remarkable for their ability to propel themselves along the seafloor using bodies and fins. And, actually, on land – literally fishes out of water. New walking shark research by an international team of scientists has found that, in terms of evolution, they are the most recent group of sharks to arrive on the scene. DESPITE A COMMON MISCONCEPTION, only a small numberRead more
Identifying sharks and rays featured thus far on Poseidon’s Web.
POCKET SHARKS ARE SO SINGULAR THAT AS FAR AS THE WORLD KNOWS there are only two known species – and only one specimen of each. The first resides in a museum in Russia. The second, found in the Gulf of Mexico and just identified, has been given a scientific name but it’s probably going to be known as the American pocket shark. If having one specimen each of two species makes them the world’s rarestRead more
1) THERE ARE TWO SPECIES OF MANTA RAYS – OCEAN MANTAS (MANTA BIROSTRIS) AND REEF MANTAS (MANTA ALFREDI). M. birostris is also sometimes known by the names giant ocean manta and Atlantic giant manta. Mantas are the largest members of the ray family and among the largest fishes in the sea. 2) Oceanic mantas are found worldwide, often reported as swimming great distances across oceans. They generally prefer tropical and subtropical waters. 3) Reef mantas areRead more
APPARENTLY IT TAKES TIME TO GROW TO BE THE WORLD’S BIGGEST FISH. A new study of whale shark size and age has indicated that gargantuan fishes can live to the ripe old age of 130 years. Marine biologists at the U.K.-based Maldives Whale Shark Research Programme and Florida’s Nova Southeastern University analyzed a decade’s worth of repetitive, non-invasive underwater measurements of whale sharks in the Maldives to understand whale shark age and growth details. PreviousRead more
WHERE’S WALDO? That might be the question this yellow stingray (Urobatis jamaicensis) hopes we’re asking, as it fluffs up sand to try to hide itself. In this case it didn’t work since we watched it approach and then proceed to bury itself – most ineffectively. YELLOW STINGRAY FACTS U. jamaicensis typically measures 12 to 15 inches across, excluding the tail (although the Pittsburgh Zoo & Aquarium, which has yellow stingrays in its collection, says theyRead more
SHARKS’ REPUTATION AS FIERCE, MAN-EATING APEX PREDATORS of the oceans takes a hit when you consider the bonnethead shark (Sphyrna tiburo), a small variety of hammerhead found mostly in warm waters along the Atlantic and Gulf coastlines of North and South America. Along with their normal carnivorous diet, bonnetheads eat grass, as in seagrass. How much grass? It accounts for as much as 62 percent of its gut content in some juvenile populations. The bonnetheads’Read more
Atlantic torpedo rays aren’t your usual, charismatic touristy rays, like mantas, spotted eagles or even southern stingrays. In a way, they’re more interesting. It’s not for nothing that members of the family Torpedinidae are called electric rays. The Atlantic torpedo (Torpedo nobiliana) is one of 14 species of Torpedinidae rays worldwide that can deliver an electric shock – most producing less than 80 volts. T. nobiliana delivers up to 220-volts – probably not enough to killRead more