They were only part of the soup. There was a ton of other small round ones and larger bio-lumenescent jellies as well.
The large biolumenescent guys are probably ctenophores (comb jellies). The common one is called Mnemiopsis leidyi. The little round guys were probably another type of comb jelly. If they had two long tentacles, one on either side, it was probably the "sea gooseberry" aka Plueorbrachia pileus. If it had no tentacles it was probably Beroe sp. .