Barnacle
One of the most common organisms found on the seashore are barnacles (Barn-ick-call), which are found in the phylum Anthropod (Ant-throw-pod). They are related to crabs and lobsters. The Mi’kmaq word for barnacles on rocks is “okskedooltijik” (oscor-do-al-ti-chick), though they can be found on a lot of other objects on the shore, such as seaweed, wood, and other debris on the beach. They also can be found attached to boats, docks, and even whales. Barnacles grow around the world and can be found on almost every shore in Nova Scotia. They are even able to grow in the Arctic.
Life Cycle
Adult barnacles are sessile (Cess-isle) which means they aren’t mobile. To arrive at their permanent home they start their lifecycle as eggs, hatch into a larva called Nauplius (Nau-plea-us), molt into a Cyprid (Si-p-rid), and find a location to molt into the adult form as the barnacle we commonly see on rocks. With a glue they create themselves, they attach themselves to the rocks by their head, with their arms sticking up in the water.
Lifestyle
Barnacles like to live near the top of the water column in the ocean where their food source is located. They are suspension feeders, removing food from the water with their feathered arms, called cirri (See-ree). Using these feathered arms, they remove plankton and detritus from the water. Plankton are single-celled organisms while detritus is small, broken pieces from plants and other animals. Barnacles also use their arms to take oxygen from the water to breathe as they don’t have gills.
Like every other animal in the world, barnacles have to be careful of predators. Their main predators are whelks (well-k-s) and starfish. While they are unable to move to avoid predators, they have a shell around themselves like lobsters and crabs. They can close their shell off when they aren’t feeding by using their two shell plates to make a beak-like shape. Closing their shell also keeps water within for barnacles, since they aren’t able to survive outside of saltwater. Much like lobsters and crabs, barnacles shed their shells when they become too small, causing barnacles to appear to grow in bursts. This means that there is normally a range of old empty shells and live barnacles present in each cluster.
Biomimicry
The glue that barnacles use is special because it is made and “applied” and sets underwater and lasts for a really long time. Researchers are trying to copy the glue made by barnacles and other organisms, such as mussels.
(https://asknature.org/strategy/multiple-component-glue-aids-underwater-adhesion/)
Experiment:
If you want see the arms of barnacles, the barnacles need to be in the water in bright daylight. With the assistance and supervision of an adult, you can create a micro-environment around some barnacles on an exposed rock or log away from the water. Then you can become a Cirripedologist (Syrup-pit-olo-gist), or someone who studies barnacles!
Equipment Needed:
- A clear glass or container
- Seawater
- Naturally found barnacles
Steps:
- Fill the clear glass or container with saltwater.
- Place glass full of water over selected barnacle(s).
- Wait for barnacles to extend their arms in the water. This can take one to two minutes for the barnacles to come out.
- Watch and enjoy!
- Remove the cup to leave the barnacle(s) in their natural habitat.
Emilie Knighton
