Sunday, August 31, 2014

Shape of the seahorse

yellow thorny seahorse
Standing up straight is relative
when you are a seahorse
photo: Peter Ryngaert, Project Seahorse
Guylian Seahorses of the World 2005
You may have been told to stand tall and sit up straight, but seahorses do the opposite: they maintain a weird curvy body shape to find food and avoid becoming some other fish's dinner.

Seahorses are master hunters, catching prey on over 90% of attacks. Who knew?

Seahorses are ambush predators, meaning they sit still and pretend to be vegetation until a suitable prey – in their case, tiny copepods and other shrimp-like crustaceans – swims by, and then they attack with a lightning-fast strike.

To be so effective, a sit-around-and-wait predator must be sneaky and stealthy, and seahorses excel at hiding in plain sight.

Although they are slow swimmers, according to marine biologist Brad Gemmell, at the University of Texas at Austin, seahorses "...tend to anchor themselves to surfaces like seagrass with their prehensile tails." (Prehensile tails, like those of some monkeys and possums, can grasp items, like branches or coral.)

So they are slow swimmers, and they prefer to attach themselves to a rock or grass. Their prey, the copepods, are super-sensitive to motion in the ocean and can swim away at a speed equivalent to a 6-foot human swimming 2,000 miles per hour.  How do the seahorses catch them?

Saturday, August 23, 2014

A kangaroo and a koala walk into a bar...

even joeys disobey
photo: FunnyJokePictures
...and the kangaroo says "I'm worried about my little Joey's future, he's a complete pouch potato".

Both kangaroos and koalas (and wallabies, quolls, Tasmanian devils, and wombats, to name just a few) are marsupials — mammals with a pouch, called a marsupium, in which their infants, called joeys, develop.

Instead of developing in the womb fed with nutrients through the placenta, like we and most mammals are, marsupial joeys are born very early, very blind and very bald, and find their way to a nipple in their mom's pouch.

They stay attached to it suckling milk for weeks, without moving, while they grow. Once developed, they can survive outside the pouch for short periods, but they return regularly to their mom's pouch for warmth and protection for up to a year.

With that in mind, enjoy some True Facts about Marsupials:

Video courtesy of ZeFrank

I love combining funny and educational, and the True Fact series do just that.

While this video highlights the more famous marsupials of Australia, there are many others, both in Australia and in South America. In fact, these and the other Aussie marsupials actually descended from an ancestor in the Americas.

We came from Where??
photo: CFZAustralia
Yes, it's true, Joe, just ask your DNA.

The Americas still have 99 of 334 species of marsupials, mostly small nocturnal species, all but one in South America. Although just one, the Virginia opossum, still occurs naturally in the U.S., North America used to have numerous marsupial species. Most of the now-extinct American species likely lost out to placental mammals that charged south once the Central American land bridge formed between North and South America.

Australian and New Guinean marsupials didn't face that threat until recently, when people brought rabbits and sheep that changed the continent's vegetation and dogs, foxes, cats, rats, weasels, and other non-native predators that ate native mammals.

a numbat, one of many wonderful marsupials on the brink
photo: Perth Zoo

For all those millennia, marsupials didn't need strategies to deal with such efficient hunters, especially people themselves, so now, populations of some species (bilbies, bandicoots, numbats, potaroos, koalas, to name a few) are in serious trouble and will need substantial help from people to persist.

There is still a crazy variety of marsupials -- which is your favorite?

Sunday, August 17, 2014

Ramen are common but take stock of their dark side

image: QuickMeme
Who hasn't eaten instant ramen noodles?

They're faster, cheaper, and saltier than KFC or a Big Mac. They're super easy and so popular that they are a staple food across many countries.

That beloved staple of college students, new graduates, and people everywhere with limited time or cooking skills, is, not surprisingly, also ubiquitous all over eastern and southern Asia.

And, as you might guess from the packaging and instant nature of them, they're not on any government recommended food pyramids. But you'd probably already guessed that, right?

But are they really that bad for us?

Thursday, August 14, 2014

What our friends think we eat

From Runners World, but probably applies to athletes of various stripes: What our friends think we eat, what we "should" eat, and what we actually eat. The three aren't the same. Which pyramid is yours?

Tuesday, August 12, 2014

How do bats both resist and transmit Ebola?

Ebola virus is the latest killer pathogen to make international news, and scientists are striving not only to keep people alive and prevent new cases, but also to better understand how the disease spreads and where it came from.

Ebola had not been seen in West Africa before the current outbreak. The strain now causing such tragedy in Guinea (where it started – here's a map), Nigeria, Sierra Leone, and Liberia is originally from Central Africa.

Scientists know the disease spreads through bodily fluids -- blood, tissue, saliva, urine, semen, feces -- and they have strong evidence that it doesn't spread through the air (mercifully).

So how did it cross all the way into West Africa?  There are 2 theories:  Bats and Bushmeat.

Tuesday, August 5, 2014

How Animals Eat (one interpretation!)

Last year, I started writing about the different eating strategies in the animal world. Got off to a great start with herbivory -- eating plants -- and then managed to get sidetracked with human diets and not continue with carnivory (eating meat), granivory (eating seeds), frugivory (eating fruits), etc in the rest of the animal kingdom.

I still plan to catch up on these, but in the meantime, try to keep a straight face watching this rendition of How Animals Eat Their Food:

Any votes on the accuracy and precision of these reenactments?