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Wild Life: Big Chill for Manatees
Big Chill for Manatees
One of the saddest sights during winter cold spells in Florida is that of dead or dying manatees washing up on shore. Despite their half-ton heft, water temperatures below 68 degrees can be fatal for these endangered marine mammals.
Just how or why manatees succumb in comparatively warm water had been a mystery. But recently scientists from the Harbor Branch Oceanographic Institution in Florida discovered that a manatee’s metabolism is unable to cope with prolonged exposure to cool water, leading to weight loss and lower immunity, in turn making the animal prone to pneumonia, intestinal infections and longer-term health problems.
Says biologist Gregory Bossart, who led the study, “Cold-stress syndrome needs to be taken into account in any discussion of threats to the manatee’s viability in the United States ."
Strange Brew
It’s a feat of alchemy bordering on witchcraft: a creature ingests a toxin and transforms it into something even more powerful to ward off enemies.
This is no Halloween tale—just a typical day for some poison frogs of Central and South America . These small, colorful tropical frogs have bitter chemicals in their skin that repel snakes and other predators. (Three species of poison frogs are so toxic they have been used by Indians to poison blow-darts.) The chemical toxins come originally from insects the frogs eat.
A team of researchers from the National Institutes of Health recently found that some frogs can multiply the power of the insect toxins. Using an enzyme in their bodies, green-and-black poison frogs and two other species transmute the bitter chemicals into something five times stronger, which they store on their skin. This helps the frogs by making them more unpalatable to predators—and it may also aid people in the future.
Says John Daly, the chemist who led the study, “We’re now further investigating how these compounds work to see whether they might have clinical potential as new drugs or research tools."
Pint-Sized Pony Discovered
Move over, Seabiscuit—there’s a new horse in town. Like the star of the recent movie, it’s small and lively, but it will never race at Pimlico.
The recently discovered horse is of the ocean-going variety: Denise’s pygmy sea horse. And this peach-colored equine’s claim to fame is its size. At about five-eighths of an inch long, it’s smaller than a dime—the tiniest sea horse species in the world.
The sea horse was found darting among the branches of sea fans on Indonesian reefs and was named after underwater photographer Denise Tackett, who first documented the creature. Experts at first thought these diminutive fish were babies of another species, but biologist Sara Lourie of McGill University in Canada recently proved they were unique and full-grown.
“There’s a lot of bad news about species going extinct," says Lourie. “Finding a new species is good news—it shows there’s still a lot we don’t know about the natural world."
