How were the fish used in this lab captured?

• A. They used nets set in the water and left overnight.
• B. They collected by hand while snorkeling.
• C. They deployed traps and retrieved them immediately after deployment.
• D. They pull traps out of the water to collect the live fish.

Answer: (D)

This question tests understanding of a practical, humane way to capture live fish in a lab setting. Using traps that are placed in the water and then pulled out to collect the fish is a common method because it allows fish to enter the traps voluntarily, minimizes handling and stress, and lets researchers control exactly how many fish are taken and when they’re processed. It also reduces risk to divers and avoids the problems that can come with longer confinement, such as oxygen depletion or injury.

Leaving nets in the water overnight can stress or harm the fish and disrupt their environment, making the sample less reliable. Collecting fish by hand while snorkeling limits what can be reached and may bias the sample toward more visible individuals. Pulling traps out to retrieve live fish provides a controlled, efficient, and humane approach that aligns with the needs of most lab studies.