Deep-Sea, Swimming Worms with Luminescent "Bombs"
Karen J. Osborn,1,*
Steven H. D. Haddock,2
Fredrik Pleijel,3
Laurence P. Madin,4
Greg W. Rouse1
By using remotely operated vehicles, we found seven previously
unknown species of swimming annelid worms below 1800 meters.
Specimens were large and bore a variety of elaborate head appendages.
In addition, five species have pairs of ellipsoidal organs homologous
to branchiae that produce brilliant green bioluminescence when
autotomized. Five genes were used to determine the evolutionary
relationships of these worms within Cirratuliformia. These species
form a clade within Acrocirridae and were not closely related
to either of the two known pelagic cirratuliforms. Thus, this
clade represents a third invasion of the pelagic realm from
Cirratuliformia. This finding emphasizes the wealth of discoveries
to be made in pelagic and deep demersal habitats.
2 Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, CA 95039, USA.
3 Department of Marine Ecology - Tjärnö, University of Göteborg, SE 452 96 Strömstad, Sweden.
4 Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA 02543, USA.
* To whom correspondence should be addressed. E-mail: kjosborn{at}ucsd.edu
