costia (noun)

1. The protagonist in the anime series discovers a hidden world where mythical creatures, including the costia, reside.

2. The artist created a captivating painting featuring a school of fish affected by the costia disease, highlighting the impact of pollution on marine life.

3. The aquarium's design incorporated curved glass panels to provide a visually stunning showcase for the different species of fish, including those affected by costia.

4. The fictional novel depicted a dystopian society where a mysterious costia outbreak threatened the existence of all aquatic lifeforms.