The open ocean - A Fascination for Fish: Adventures of an Underwater Pioneer - page 261

inal tank, it would keep the fragile planktonic animals healthy and
happy—if animals without a brain can experience “happiness.” The
end result would look like jellies swimming in the limitless blue of the
open ocean.
To test this idea, John Christiansen and I added a thin sheet of translu-
cent blue acrylic to the back of a transparent kreisel tank. We then re-
duced the size of the circular window opening so that the tank walls
were out of sight. A fluorescent light behind the tank illuminated the
blue back and a narrow spotlight shining in from the side of the tank
lit the jellies.
Although the tank was rather small, the idea worked: all you saw
were the illuminated jellies against an ocean-blue background. We also
tested it on comb jellies ( Pleurobrachia and Beroe spp.), and the side
lighting made their iridescent rows of beating cilia ripple with rain-
bow colors. The comb jellies looked stunning, like shimmering alien
space ships.
We knew then we were on the threshold of creating truly exciting
jelly exhibits. Attempts to share our excitement with other sta¤, how-
ever, often proved frustrating. Some were impressed, but others saw
only a small, improvised tank in a wet, funky lab and seemed unable
to project beyond it to visualize how a future, large-scale jelly exhibit
might look.
After her successes with the moon jelly, Freya became interested in
the beautiful purple-striped jelly ( Pelagia colorata ), which in some years
is quite common o¤ the California coast. Virtually nothing was known
of its life cycle, but biologists assumed that its reproduction was sim-
ilar to that of its East Coast relative, Pelagia noctiluca, whose larvae skip
the polyp stage and develop directly into young jellies within the fe-
male. Much to her surprise, Freya found that the California species
didn't produce young swimming jellies at all, but, like the moon jelly,
produced larvae that settled out and developed into tiny polyps, which
in turn divided to form more polyps and some time later released tiny
free-swimming jellies.
I remember an excited Freya bringing a bowl of the tiny jellies up-
stairs for Chuck Farwell and me to see. Not only was this an outstanding
husbandry success, but it was also a scientific breakthrough. This dis-