Final answer:
Sea spiders have long, narrow, and flexible arms to capture prey. They also have movable spines to conserve energy.
Step-by-step explanation:
One adaptation that sea spiders have for gathering food is their long, narrow, and flexible arms. These arms allow them to capture prey for their own food. Sea spiders are bottom feeders, and their arms enable them to move relatively quickly to capture their prey.
In terms of conserving energy, sea spiders have movable spines. These spines are used for movement, defense, and sensing the environment. By using these spines efficiently, sea spiders can conserve energy and avoid unnecessary movements when not necessary.