Barnacles use their antennae to filter particles out of the water. Select one:
a. True
b. False
The correct answer and explanation is:
Correct Answer: O b. False
Barnacles do not use their antennae to filter particles out of the water. Instead, they use specialized appendages known as cirri. Cirri are feathery, leg-like structures that extend out from the barnacle’s shell and sweep through the water to capture plankton and organic debris. These structures are highly adapted for filter feeding and are distinct from antennae, which serve different functions in crustaceans, such as sensing the environment.
Barnacles are crustaceans, closely related to crabs and lobsters. Unlike many other crustaceans, barnacles are sessile as adults, meaning they attach themselves permanently to surfaces such as rocks, boat hulls, or even marine animals. Once attached, they secrete a calcareous shell that protects their body. Inside this shell, barnacles use their cirri to collect food particles from the surrounding water.
The cirri beat rhythmically to create water currents and trap plankton and other microscopic organisms. Once the food particles are caught, they are directed toward the mouth of the barnacle for ingestion. This feeding mechanism is efficient and allows barnacles to thrive in intertidal zones where water flow brings a steady supply of nutrients.
Antennae, on the other hand, are sensory structures found in crustaceans that are used for detecting changes in the environment such as vibrations, chemical signals, and touch. While barnacle larvae use their antennae to find a suitable surface to attach to during metamorphosis, these structures are no longer used for feeding in adult barnacles.
In conclusion, barnacles use cirri, not antennae, to filter food from the water. The idea that they use antennae for feeding is incorrect and likely stems from confusion with their larval stage, where antennae are more functional.