Which trait is characteristic of Sisyridae larvae?

• A. They are fully aquatic.
• B. They are terrestrial detritivores.
• C. They are arboreal predators on land insects.
• D. They are parasitic in aquatic hosts.

Answer: (A)

Sisyridae larvae are fully aquatic in their larval stage. In freshwater habitats—streams and ponds—they live underwater and rely on aquatic respiration, often scraping or preying on aquatic invertebrates, with a specialization for feeding on freshwater sponges. This makes them distinct from terrestrial detritivores, arboreal land predators, or parasites that require a living host. Their life cycle includes a water-bound larval period that ends with a metamorphosis to a winged adult, so the aquatic nature of the larval stage is the defining trait.