Sandy crawlers

Some days ago I was in the lab when a collegue of mine finished working on a macrobenthos (animals > 1 mm living in seabed) sample

I put two flashes underneath the dish and one above, in order to photograph these benthic creatures in a white setting. I don't like it when everything is clipped so I didn't flash very hard.

The animals are red due to coloring with a sort of eosin.

Who is the first to guess half of the species (or genera) present in these samples?