marine fluorescence

Mahlon G. Kelly mgk at darwin.clas.Virginia.EDU
Fri Sep 1 06:14:19 EST 1995

HOTEZ at  writes:
> 	Recently I was fishing in a salt pond in RI one evening. The water
> contained organisms that, upon disturbance (i.e. kicking or splashing), would
> fluoresce. We found some of this fluorescence associated with a jeelyfish of
> unknown identification, and one of the locals refered to them as "jellies", but
> it also appeared that there were some free-floating in the water also. I have
> seen similar fluorescent organisms in the waters around Cape Cod, and was told
> that they were diatoms. Is anyone familiar with these fluorescent organisms, and
> can you direct me to any literature about them?
> Thanks in advance
> John M. Hawdon
> hotez at
What you were observing was not flourescence, but
bioluminescence. Diatoms do not produce light, although
dinoflagellates do. However, to see dino luminescence, except
in extreme conditions (which do not occur in RI), you have to
be very dark adapted. It is almost certain that what you saw
were "comb jellies" or ctenophores. Biologists still argue
whether they are in their own phylum or in with the
coelenterates. Nevertheless, they do produce beautiful light.

In fact, I would be willing to bet a bit of money $0.10?, that
the species you saw was Mnemiopsis Leidyi. That fragile critter
is the most common of the luminescent folks on the New England
Associate Professor (Emeritus)
University of Virginia
mgk at

More information about the Bioforum mailing list