
DATE: Saturday, September 20, 1997          TAG: 9709190182

SECTION: DAILY BREAK             PAGE: E7   EDITION: FINAL 

SOURCE: BY MARY REID BARROW, STAFF WRITER 

                                            LENGTH:   91 lines

MARINE SCIENCE MUSEUM OPENS PROGRAM ON JELLYFISH

JELLYFISH HAVE neither a heart nor brain, but they're not exactly senseless when it comes to firing off their stingers.

These blobs of clear jelly with their long barbed tentacles are the bane of Chesapeake Bay swimmers in summer, but they can become almost endearing if you talk to Jeff Campsen.

Campsen, a senior aquarist at the Virginia Marine Science Museum, knows them well because he oversees the general welfare of the stinging nettles and moon jellies that float through the museum's two beautiful aquariums.

In their own brainless way, the stinging nettles in particular, can distinguish the difference between a museum staffer's arm in the aquarium and the many little brine shrimp on which they dine. Even when the humans brush against the tentacles armed with stingers, the jellyfish stay cool.

Although jellyfish lack eyes as well as a brain, they do have nerve cells that help them move and help them react to what's food and danger and what's not.

Campsen and other museum staffers relate such facts about the critters during the museum's ``Jelly Jubilee'' from 9 a.m. to 5 p.m. today through Sept. 28. They'll take you behind the scenes to show you what goes into keeping these fragile critters in captivity.

And like a proud grandfather, Campsen will show off tiny jellies, less than a fourth of an inch long, offspring of the museum's resident moon jellies. You'll see the many stages the youngsters go through as they grow up to be the old familiar jellyfish in Bay and ocean waters.

Some of the tiniest are swimming upside down like inverted umbrellas caught in the wind. At this stage, right before they are about to metamorphose into a true stinging nettle, they are called ephyrae.

You also will see miniature sea anemone-like critters attached to an aquarium bottom, an even earlier stage of the jellyfish's transformation, when they are called polyps. Jellies begin life as microscopic forms, much like plankton.

You'll learn that no ordinary aquarium can serve as a jellyfish home. Museum jellyfish live in round, water-filled disks, developed a decade or so ago in Germany by scientists who wanted to keep the critters alive in order to study them.

They must rely on ocean currents in addition to pulsing their bell-shaped bodies to move through the sea. Without currents to help keep them afloat, jellyfish would drop to the bottom of an aquarium, their weak pulsing would be to no avail and they eventually would die.

The disk aquarium was designed with a filter in the top that sends water gently into the aquarium, creating an ocean current of sorts that moves the jellyfish around in a circle. The filter also is specially designed so the jellies won't be swept into the outtake valve, another hazard the poor swimmers face in an ordinary aquarium. A chilling system keeps the water between 62 and 68 degrees and a sterilizer keeps it clean and healthy.

``They are very delicate animals,'' Campsen said, ``and a lot goes into keeping them alive.''

Watching the graceful creatures pulse slowly around the museum aquariums, you'll see their tentacles get longer and longer and then slowly retract. They are even able to gather food in just two tentacles and retract only those, Campsen said.

Occasionally one, two or more jellyfish will tangle up, their tentacles becoming completely intertwined, but never for too long. Then the streamers draw up and the jellyfish are free and on their own again.

Life at the museum appears to agree with the jellyfish, Campsen said.

With a life span of about a year in the wild, they live longer than that in the museum's slow-motion world where food is plentiful and summer is endless. ILLUSTRATION: Graphic

SPECIAL JELLYFISH EVENTS

Jelly Jubilee, a series of programs on jellyfish, begins today

and continues through Sept. 28 at the Virginia Marine Science

Museum, 717 General Booth Blvd. Call 425-FISH for more information.

The following events, except mini-camp, are free with museum

admission:

Jelly Jubilee Mini-Camp. A morning of jellyfish activities and

crafts for grades 2 to 6, beginning at 9 a.m. today in the museum's

main building. Fee is $12 for members and $18 for non-members. No

reservations needed.

From Undersea to Outer Space. A program at 11 a.m. today only in

the IMAX theater by Dorothy B. Spangenberg from Eastern Virginia