Sunday, July 31, 2016

Head, shoulders, trunks and toes: how to tell elephant species apart

Up ahead, you see a massive grey animal. It has very little hair, small eyes and a long trunk for a nose. An elephant, of course. But do you know the difference between African and Asian elephants?

Here are the basics:

They are two different species!
Image credit: Thomson Safaris, Pinterest


Sunday, July 3, 2016

Octopuses take on aqua-jogging

octopus jetting across the ocean floor
An octopus jets across the ocean floor. Fwooosh!
Photo: Albert Kok, Wikimedia
Any injured runners who have tried to "run" in the water know it's hard -- the resistance to movement in water is far greater than in air -- so why would an octopus run?

Especially when they typically move through the water by jet propulsion.

Octopuses (octopi?), like other cephalopods, have both a mouth, which sits in the center of their arms, and a tube-shaped organ called a funnel, or siphon, near their heads, that they use to breathe by bringing oxygenated water to their gills.

They also use the siphon to create their own personal jet propulsion, by filling up their muscular mantle cavity (their body, basically) with water and then quickly expelling the water out of the siphon. Fwoooosh.