What is the function of the rectal gland in the shark?
The correct answer and explanation is:
The rectal gland in sharks plays a crucial role in osmoregulation, which is the process of maintaining a balance of salts and water in the body. Sharks, like many marine organisms, live in saltwater, where the concentration of salts outside their bodies is much higher than inside. This creates a challenge for sharks, as they need to prevent dehydration and maintain the proper concentration of ions within their tissues.
The rectal gland is responsible for excreting excess salts that enter the shark’s body from the surrounding seawater. It does this by actively secreting sodium chloride (NaCl), which helps to maintain the proper internal environment. The rectal gland is an adaptation to the osmotic pressure of the ocean water, and it ensures that the shark doesn’t become overly saturated with salt.
The gland works by filtering the blood and concentrating the salts into a fluid, which is then excreted through the rectum. This process helps to regulate the shark’s internal salinity levels, ensuring that the shark does not become dehydrated or suffer from salt toxicity.
In sharks, the rectal gland is part of a larger osmoregulatory system that includes the kidneys and other organs. The kidneys filter waste products from the blood, while the rectal gland focuses specifically on the removal of excess salts. The rectal gland also helps to maintain blood pressure and ensures that the shark can continue to function efficiently in a hypertonic environment.
Overall, the rectal gland is an essential part of a shark’s survival in the ocean, as it helps the shark to balance the salts in its body and maintain proper hydration levels in the face of high salinity.