Here's what I've been doing for the past two weeks or so... Frantically hunting the docks for my bryozoans and videotaping the larvae.
I am basically trying to see if there is a relationship between larval size and juvenile size. So, after videotaping my little larvae, I settle them and take a look at the juvenile feeding structure. The idea is that these larvae don't feed until after they are juveniles, so the size they are reflects how much energy they have. Any differences between larval size (and thus energy content) should translate into differences in juvenile size.
These larvae swim using cilia, which is either in several rows around the larvae (1st larva) or in a large band around the center of the larvae (2nd larva). They both have a ciliated groove which not only helps propel them, but they also use to 'smell' the surface (so they can find a good spot to settle on).