You have reached your limit of free articles this month.

Enjoy unlimited access to myStatesman.com

Starting at just 99¢ for 8 weeks.

GREAT REASONS TO SUBSCRIBE TODAY!

  • IN-DEPTH REPORTING
  • INTERACTIVE STORYTELLING
  • NEW TOPICS & COVERAGE
  • ePAPER
X

You have read of premium articles.

Get unlimited access to all of our breaking news, in-depth coverage and bonus content- exclusively for subscribers. Starting at just 99¢ for 8 weeks

X

Welcome to myStatesman.com

This subscriber-only site gives you exclusive access to breaking news, in-depth coverage, exclusive interactives and bonus content.

You can read free articles of your choice a month that are only available on myStatesman.com.

The beauty of a starfish larva at lunch


It was one of those lovely nights when the moonlight on Monterey Bay makes you wonder: What would happen if I put some microbeads in with the starfish larvae?

At least that’s what you wonder if you are Manu Prakash, who runs a laboratory at Stanford University and is intrigued by the way life is shaped by the laws of physics.

He was actually in a lab that night, with the bay just outside. He and his colleagues had collected the starfish larvae from the bay with other invertebrates that they were studying.

The larvae were from a species called the bat star, and they propel themselves, like many other small invertebrates, by the beating of many, many hairlike cilia. “They look like alien starships,” Prakash said.

He put the beads in the seawater with the larvae under a microscope to watch the turbulence they produce as they swim. The beads, smaller than red blood cells, follow even small swirls of water and reflect light, so the lines of water flow are visible.

What he saw entranced him. Under the microscope, cilia on the surface of a larva look “almost like an ornament — a line that goes around the edge of the animal,” Prakash said.

If they all beat together, the larva moves as fast as it can. But if some patches of cilia beat against the prevailing motion, they create vortexes, swirling eddies that the researchers found bring algae close to the surface of the larva and, eventually, to its mouth.

The larva varies its speed by the number of vortexes it creates. It may make as few as two, in which case it swims along at a good clip and eats little, or as many as six, slowing down to munch the daisies, or algae. After a year of study, Parkash and his colleagues recently produced detailed mathematical descriptions of how this all works.

The vortexes also pull in particles of a certain size, so that the tiny animal gets the food it wants. This kind of filtering is very different from the sieves and nets that humans use to separate out particles of a certain size.

It is used by not just starfish larvae, but countless billions of other microscopic invertebrates that filter food from the oceans. Yet the research was never intended to explain a biological phenomenon, Prakash said, beginning only “with a very pure question of shape and beauty and form.” See the video at nytimes.com/sciencetake.


Reader Comments ...


Next Up in Austin360 Eats

Versatile Texas actor Bill Paxton’s career was all over the place in the best way
Versatile Texas actor Bill Paxton’s career was all over the place in the best way

Bill Paxton, looking concerned, as Fred Haise in “Apollo 13” Fort Worth-born actor Bill Paxton, he of “Aliens,” “Big Love” and “Apollo 13” fame (among many, many other roles) has died from complications during surgery.
Actor Bill Paxton of 'Aliens,' 'Titanic' fame dead at 61
Actor Bill Paxton of 'Aliens,' 'Titanic' fame dead at 61

Award-winning actor Bill Paxton of "Aliens" and "Titanic" movie fame, has died from complications from surgery, according to TMZ. The 61 year old acting veteran has starred in a string of movie hits over his four-decade career, including "Twister," "Hatfield and McCoys," and "Apollo 13." He was working...
A healthful risotto that doesn't cause a stir
A healthful risotto that doesn't cause a stir

I have a risotto conflict. I love the traditional dish - made with arborio, carnaroli or another short-grain white rice that swells up and combines with the cheese and butter to get so wonderfully creamy. But like so many other health-conscious cooks, I'm also trying to favor whole grains whenever possible. So I've broken with tradition and made risotto...
Exhibit looks at American landscapes, for better or worse
Exhibit looks at American landscapes, for better or worse

Art “Kindred Spirits.” In this two-person exhibition of paintings at Davis Gallery, David Leonard and Daniel Blagg consider our changing world through their work, Leonard with his detailed depictions of modern American cityscapes and Blagg with a look at the decay of American architecture. Both artists ask through their work if the modifications...
March brings us Spoon, South by Southwest and Wire’s ‘Silver/Lead’
March brings us Spoon, South by Southwest and Wire’s ‘Silver/Lead’

Here are some of the best and highest-profile new releases in music, movies, TV and more on the horizon in March. As always, dates are subject to change without notice. 1. Spoon, “Hot Thoughts” (Matador). And suddenly it feels like 1996. Back in the middle of the Clinton administration, the first Spoon album, “Telephono,” was...
More Stories