Why do barnacles attach to rocks

When the northern rock barnacle opens its mouth, featherlike feeding legs emerge to gather phytoplankton from the water.

These feathery legs are also used as gills to extract oxygen from the water. These feathery appendages are also jointed. Northern rock barnacles have an exoskeleton, like all crustaceans. They grow by shedding the exoskeleton through molting. Molted exoskeletons can be seen floating on the water's surface. Northern rock barnacles begin life as planktonic larvae in the water column, often aggregating in large clusters when they settle to the bottom.

Reproduction is sexual, which requires the animals settle in close proximity to one another. The cyprid larvae has special attachment devices which allow it to hold onto the substrate, e. Once settled, the barnacle develops into an adult and attaches in various ways: gripping the skin, cementing to the shell or boring into it. Adult barnacles are filter feeders, thus benefit from a constant flow of water around them.

As sessile creatures they can achieve that by a settling in an area with pronounced water movement e. Even though barnacles are quite safely attached, barnacles actually are capable of moving as adults! They most likely achieve this through an extension of their cemented base as well as through muscle activity. Most barnacles do not hurt sea turtles as they are only attached to the shell or skin on the outside. Others though burrow into the skin of the host and might cause discomfort and provide an open target area for following infections.

Excessive barnacle cover can be a sign of general bad health of a turtle. While they do occasionally self-fertilize, most barnacles fertilize with a nearby barnacle in a process called cross-fertilization. Barnacles both attach themselves to and burrow inside objects. You may have seen them on a variety of surfaces—covering pilings and rocks or clinging to the hull of a ship or the outside of a crab; they even attach themselves to larger animals like whales. But what you might not have seen are burrowing barnacles.

Gooseneck barnacles, acorn or rock barnacles, burrowing barnacles, wart barnacles—these are the common names for some barnacle species. They vary in shape: some are stalked, some are not, some have symmetrical shells, some look like fungi. Tide pools are found on rocky beaches in the strip of land between high and low tide, called the intertidal zone.

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