Final answer:
Larvaceans secrete their own mucus houses using special glands called the endostyle glands located in their pharynx. The mucus house is made of the complex carbohydrate cellulose and serves as a filter-feeding structure to capture food particles.
Step-by-step explanation:
The larvaceans secrete their own mucus houses, which serve as a protective structure. These mucus houses are secreted by special glands called the endostyle glands located in the pharynx of the larvaceans. The mucus house is made up of a complex carbohydrate called cellulose. Larvaceans continuously produce mucus to capture food particles and create a filter-feeding structure that helps them obtain nutrients.