How do aquatic birds such as the wandering albatross avoid becoming dehydrated even though they live in an environment that is almost entirely salt water?

• A. They don't actually swallow the salt water.
• B. They excrete excess salt in their urine.
• C. Like animals that live in extremely arid conditions, they are able to survive for long periods of time without fresh water, only drinking when they have access to fresh water on land or from rainwater.
• D. They are able to maintain their osmolarity close to that of seawater by maintaining salt, urea, and trimethylamine oxide levels in their body fluids, thus preventing the salt water from diffusing into their cells.
• E. They actively transport excess salt from the blood into secretory tubules found in special excretory glands.

Answer: (E)

Verified step by step guidance

1. Understand the challenge aquatic birds face: They live in environments with high salt concentrations, which can lead to dehydration if they consume salt water.
2. Recognize that aquatic birds have specialized adaptations to manage salt intake and maintain water balance.
3. Identify the role of specialized excretory glands: These glands are crucial for removing excess salt from the bloodstream.
4. Learn about the process of active transport: This is the mechanism by which birds move excess salt from their blood into the secretory tubules of these glands.
5. Conclude that by actively transporting salt out of their bodies, aquatic birds like the wandering albatross can avoid dehydration and maintain osmotic balance.