I found this fast swimming animal yesterday in the nocturnal plankton and it was about 5mm long.
It is famous because it can be bred in the laboratory and there are many studies about its eyes, the lunar rhythmus, the evolution ecc.,
cfr. the Platynereis homepage: http://www.uni-giessen.de/~gf1019/home/
2 pictures, brigthfield, objective 4x
Franz

