You've things like the gut, the ink sack and the gills that you can spot but other than that, squids, mid water squids are almost completely transparent. With the exception of animals like Bruce showed you, this is Octopoteuthis which is the exception to almost every rule. This is the one I like to give to invertebrate biology students on lab practicals. But this is the eight armed squid with a little bioluminescent tips at the tops of the arms. There are those octopuses that are transparent, and this is the Vitrellodonella , a transparent, mid water octopus.
Alciopid worms are polychaetes that are very abundant in the mid water.
This is one of the more abundant ones. What happens is, as far as we can find out, is that the ctenophores actually eat the eggs of the alcioped worms, the alcioped worms get into the stomach, they hatch out of the stomach, and start eating their way out. Tough way to go. Here is another tomopterid worm with a bright red gut. The bright red gut we think probably has a function in terms of protecting itself from predators.