Whitney Lab solves mystery of clear creatures along beach
By DINAH VOYLES PULVER
Staff Writer

ORMOND-BY-THE-SEA -- A pair of hurricanes passing far out in the ocean
wound up leaving a prickly mystery on local beaches.

Millions of sparkling, needle-like shells washed up earlier this month.
They were a nuisance to swimmers and walkers, sharp and irritating to
those who stepped on them or picked them up for a closer look. But the
identity of the strange visitors was elusive.

A few beachgoers wondered if the piles of clear, glass-like shards were
fiberglass. Others called Volusia County's Marine Science Center, where
officials thought the shards were pieces of the skeletons of deep sea
sponges, called spicules. The News-Journal even reported the piles were
probably spicules. But they weren't.
Scientists at Whitney Lab recognized the mysterious arrivals. Clear,
conical and a few millimeters long, they were miniature mollusks called
sea butterflies or needle pteropods.

"They're beautiful," said Michael Brothers, the science center's
director, when he finally got a look at a sample under a microscope.
Pieces that looked like small rods on the sand, became clear,
cylindrical cones under the eyepiece.
Experts say they're even more beautiful when you see them up close as
they move in the water.
They're also very interesting, said Carol Lalli, a pteropod expert who
co-authored the book "Pelagic Snails."

The scientific name for this group of snails is Creseis, and most of the
ones that washed up in Volusia and Flagler counties recently were
Creseis acicula, Lalli said, after looking at a photo provided by The
News-Journal. They live all of their lives in the ocean, coming ashore
only when blown by the winds, and float with the current, moving up and
down vertically in the water.

Other incidents of the snails getting washed ashore have been reported
around the world, Lalli said, on the west coast of Australia and Japan.
This is the second year they've been seen on local beaches.
"We almost never found them in quantities like that when we were looking
for them at sea," said Lalli, who now lives in British Columbia. The
offshore hurricanes probably swept these ashore, she said.

Although most snails have a creeping foot, the foot of the creseis has
modified into a pair of wings used to swim.
The wings only help the creature move up and down in the water and are
no help against strong ocean currents, Lalli said. "These things can
only swim very, very feebly so any kind of turbulence going toward the
coast would carry them in and probably aggregate them into large
numbers."

dinah.pulver@news-jrnl.com

Q. What are they?
A. A pelagic snail known as creseis, they're part of a vast array of
microscopic plants (phytoplankton) and animals (zooplankton) that are
the basic foundation of the ocean's food chain.
Q. How big are they?
A. Less than an inch, only a few centimeters.
Q. What do they eat?
A. Herbivores, they spin a web of mucus and let it hang suspended in the
water above their heads. "It's so sticky that it catches very small
phytoplankton and when the web is full, the animal pulls it back into
its gut and swallows it along with any food particles," said expert
Carol Lalli.
Q. How do they reproduce?
A. They emerge from the larval stage as males. They mate with other
males and store the sperm inside their bodies. As they grow bigger, they
change into females and produce eggs.

SOURCE: Carol Lalli, Institute of Ocean Sciences Sidney, British
Columbia