Name that zoea!

Friends, it has been a productive few weeks over in my corner of the world. I'm busy at the microscope, sorting and identifying zooplankton from the Gulf of Mexico.

This zoea larva came from one of my plankton samples.
Check out that spike! Long spines and spikes help protect
plankton from predators. 

Last summer, I was part of a team investigating shipwrecks and natural hard-bottom reefs in the mesophotic zone, between 50 and 200 m deep. Recently, I've waded my way through all the ROV video we collected and found magnificent species of fish and corals along the way. The next step is to analyze plankton samples I collected when we were at sea. 

I wasn't quite sure what would be in the plankton samples or what they would show. I've been curious for a while about how animals disperse to shipwrecks as larvae, so I thought that plankton samples collected from the water column right above shipwrecks might offer some clues. 

Take a guess: Am I finding larvae of the corals and worms that inhabit the shipwrecks on the seafloor below? Am I finding something completely different? Or am I finding nothing at all? 

This megalopa larva is just about
ready to settle on the seafloor
and become a juvenile crab. 

If you selected the second option, you're correct! The larvae I have been finding in my plankton samples are completely different species from what lives on the shipwrecks. I know because the shipwrecks were dominated by cnidarians - stony corals, wire corals, and hydroids - and had tons of bearded fireworms, which eat cnidarians. My larvae in plankton samples are all crustaceans - mostly crab larvae. The two sets of species are totally different! 

Don't ask me why the species living on the shipwrecks and dispersing in the water above them are so different, because I have no clue yet. This is the exciting part of research: finding an unexpected pattern and learning something new about the world. I'm very excited to see what the plankton samples reveal!