Barnacles are invertebrates that survive well in the intertidal zone. Barnacles are
sessile (non-moving) organisms that are surrounding by a hard shell. They
permanently attach themselves to hard surfaces, such as rocks. Barnacles are
filter feeders. This means that they filter food particles out of water that passes
through their shells. When they are feeding, they open their outer shells to let
water in. When they are not feeding, they close these shells which protects them
from predators and prevents them from drying out. Based on this information and
what you have learned about the intertidal zone, describe two ways in which
barnacles are well adapted to this biome?

The intertidal zones in the ocean ecosystem undergo extreme changes due to their location on the coastlines and constant exposure to both low tides and high tides.

During high tides, the zone will submerge into seawater; and during low tides, it will be exposed out in the air.

Due to this zone elevation gradient, the organisms like the barnalces, mussels, kelps living in this zone need to be specially adapted.

The main hindrances for intertidal marine organisms are the constant changes in sea temperature, salinity levels, and strong waves.

The adaptations by barnacles are:

Barnacles also called cirripods belong to class Cirripedea due to the presence of modified legs known as “feather legs”. These are very light and help them to navigate easily in water during different tidal situations.
When exposed to rocky surfaces during low tides, they can produce cement like adhesive substance secreted from special glands which helps them to cling to the rocky surfaces
The calcareous tough multi-plated outer shell of the barnacles is exclusively adapted to suite the tidal conditions. They open and close the shell according to the tides to catch food as well as to withstand the tides.