Last week we examined cnidarians in lab. Another animal phylum traditionally thought to be closely related to corals, anemones and sea jellies are the comb jellies, or ctenophores. What is a ctenophore? Check out the video from the CreatureCast:
CreatureCast - Comb Jellies from Casey Dunn on Vimeo.
While many textbooks state that combjellies and sea jellies are sister taxa (each other's closest relative), current work suggests that they are more distantly related.
You might also enjoy some additional information on barnacle sex from the same site.