Zoop zoop riot
"Who's that swimming in the sea?
It's plankton and they're swimming free
Shells and legs and paddlin' tails
Where's your sample? Here I am!
Zoop zoop riot (riot!)
Pull up the plankton net
Zoop zoop riot (riot!)
A-pull a net through the coal-black sea
Flow Daddy!"
- my parody of "Zoot suit riot" by Cherry Poppin' Daddies
Have you ever looked at a sample of pond water under the microscope? If not, I highly recommend you try it. Just take a turkey baster full of water from your local pond, and if you don't have a microscope, you can try using a magnifying glass. A shocking number of animals live in the water.
The same is true for the Arctic Ocean. Tiny animals that live in the water column are called zooplankton (zoops for short), and I find them fascinating. This week, we've been sampling zooplankton with a plankton net from Teisten. We suspend the net vertically from the boat's winch cable, lower it to the seafloor, and then pull it back up through the water column to capture the zoops. We have some very interesting samples!
One of my favorite things we've caught so far is a pteropod, commonly known as a sea angel. Pteropods are related to snails, so you can think of the specimen we caught as a swimming slug. Pteropods use specialized appendages to swim in the water column as if they had wings. I had seen shelled pteropods ("sea butterflies," think of them as swimming snails) in numerous Arctic samples and also live in Antarctia, but I had never seen an unshelled pteropod live in the Arctic before. The species, Clione limacina, is very common in the Arctic and can even be thought of as an indicator species for Arctic water. We caught one specimen that was huge! It almost filled the bottom of a dish in the lab. This was very surprising because pteropods are usually microscopic. I wonder how this individual got to be so big!
Another organism we caught in the zooplankton net was a ctenophore, commonly known as a comb jelly. We're pretty sure the species is Mertensia ovum, which is the most common comb jelly in the Arctic. Comb jellies are kind of like jellyfish, with a body that's mostly made of water. What makes them unique is they have tiny cellular hairs called cilia arranged in rows. The cilia rows look a bit like combs and are called ctenes (hence the names). They ripple down the body of the organism to move it in the water, and as they ripple, they refract light. The effect is several rainbow waves traveling down the body of the organism each second. I find ctenophores to be gorgeous.
Some zooplankton spend their entire life-cycle in the water column, like the pteropods and ctenophores above. These animals are called "holoplankton." But some animals spend only part of their life-cycle in the water column before metamorphosing and settling on the seafloor. We call these species "meroplankton." Most meroplankton are the larval forms of things like crabs and anemones and sea stars. The meroplankton are my favorite group, because they have all sorts of strange forms that for the most part look nothing like the adults.
We found a couple meroplankton in our samples, and one in particular caught my eye. It had a lobe-like center and four appendages. Honestly, I have no idea what it is, and that's why I love it so much! I think maybe it's a very young brachiolaria larva, which means it will grow up to be a sea star. I have to do a lot more reading and investigating before I can know for sure. Most likely, I will have to use a DNA analysis to identify the species.
This is what I love about Arctic research: there are still so many things we don't know. If I'm able to identify the larva, then I will know the species it belongs to reproduces in the winter. This alone would be a big result! I'm looking forward to analyzing our plankton samples more.
It's plankton and they're swimming free
Shells and legs and paddlin' tails
Where's your sample? Here I am!
Zoop zoop riot (riot!)
Pull up the plankton net
Zoop zoop riot (riot!)
A-pull a net through the coal-black sea
Flow Daddy!"
- my parody of "Zoot suit riot" by Cherry Poppin' Daddies
 |
| Deploying the plankton net on Teisten |
The same is true for the Arctic Ocean. Tiny animals that live in the water column are called zooplankton (zoops for short), and I find them fascinating. This week, we've been sampling zooplankton with a plankton net from Teisten. We suspend the net vertically from the boat's winch cable, lower it to the seafloor, and then pull it back up through the water column to capture the zoops. We have some very interesting samples!
 |
| Clione limacina, not magnified |
 |
| The comb jelly, photographed through a dissecting microscope. |
Some zooplankton spend their entire life-cycle in the water column, like the pteropods and ctenophores above. These animals are called "holoplankton." But some animals spend only part of their life-cycle in the water column before metamorphosing and settling on the seafloor. We call these species "meroplankton." Most meroplankton are the larval forms of things like crabs and anemones and sea stars. The meroplankton are my favorite group, because they have all sorts of strange forms that for the most part look nothing like the adults.
 |
| The unknown larva, photographed with a dissecting microscope |
This is what I love about Arctic research: there are still so many things we don't know. If I'm able to identify the larva, then I will know the species it belongs to reproduces in the winter. This alone would be a big result! I'm looking forward to analyzing our plankton samples more.
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