How do Aedes group larvae position themselves for breathing?

How do Aedes group larvae position themselves for breathing?

• A. Parallel to surface with siphon underwater
• B. Floating flat on surface
• C. At an angle to the surface of the water with the respiratory siphon at the water surface
• D. Submerged completely

Answer: (C)

Aedes larvae breathe by extending a posterior siphon to the air at the water surface, so they stay mostly submerged while still getting air. Positioning themselves at an angle to the surface with the siphon tip at the air-water interface lets the siphon remain in contact with air while the rest of the body feeds and moves below the surface. This arrangement maximizes both respiration and feeding efficiency. If they were parallel to the surface with the siphon underwater, they wouldn’t have access to air. If they floated flat on the surface, the siphon would not be effectively exposed to air for breathing. If they were completely submerged, they wouldn’t receive any air at all.

Aedes larvae breathe by extending a posterior siphon to the air at the water surface, so they stay mostly submerged while still getting air. Positioning themselves at an angle to the surface with the siphon tip at the air-water interface lets the siphon remain in contact with air while the rest of the body feeds and moves below the surface. This arrangement maximizes both respiration and feeding efficiency.

If they were parallel to the surface with the siphon underwater, they wouldn’t have access to air. If they floated flat on the surface, the siphon would not be effectively exposed to air for breathing. If they were completely submerged, they wouldn’t receive any air at all.