spirula (noun)

1. Why did the spirula become a comedian? Because it had a lot of shell-arious jokes!

2. According to Greek mythology, the spirula was a precious gift from Poseidon to the sea nymphs.

3. In the novel, the protagonist stumbled upon a secret treasure chest filled with spirulas and other marine artifacts.

4. During the 18th century, spirulas were collected by naturalists and used for scientific research on mollusks.