Name the clam’s siphons.
The correct answer and explanation is:
Correct Answer:
The clam has two siphons: the incurrent siphon and the excurrent siphon.
Explanation:
Clams are bivalve mollusks that live mostly buried in sediment. To carry out essential functions like feeding, respiration, and excretion while remaining buried, clams use two tube-like structures called siphons. These siphons are formed by extensions of the mantle, which is the soft outer tissue that lines the inside of the shell.
The incurrent siphon is responsible for drawing water into the clam’s body. This water carries oxygen and food particles such as plankton and detritus. As water enters through the incurrent siphon, it flows over the gills, where gas exchange occurs. The gills also trap food particles, which are then transported to the mouth by cilia, tiny hair-like structures.
After passing over the gills and supplying oxygen, the filtered water exits the body through the excurrent siphon. This outgoing stream of water carries away carbon dioxide and waste products like ammonia. The separation of water inflow and outflow helps avoid contamination of the oxygenated incoming water with waste products.
The siphons are especially important for clams that live deeply buried in sediment. Their extended length allows the clam to stay protected while still accessing clean water above the surface of the substrate. The structure of the siphons can vary slightly among different clam species, depending on their habitat and lifestyle.
In summary, the two siphons of a clam, the incurrent and excurrent siphons, are essential for respiration, feeding, and waste removal. Their coordinated function helps maintain the internal balance of the clam while it remains safely buried in its environment.