Freshwater pearl mussel Freshwater pearl mussel The freshwater pearl mussel ("Margaritifera margaritifera") is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae. Although the name "freshwater pearl mussel" is often used for this species, other freshwater mussel species can also create pearls and some can also be used as a source of mother of pearl. In fact, most cultured pearls today come from "Hyriopsis" species in Asia, or "Amblema" species in North America, both members of the related family Unionidae; pearls are also found within species in the genus "Unio". The interior of the shell of "Margaritifera margaritifera"
Pearl Krabs Grandma's Apron, a store for elderly residents on the ground floor of the shopping center. Beatrice, her boss at Grandma's Apron, is voiced by actress Betty White. The disparity in species between Pearl and her father has never been explained directly in an episode, but merchandise makers and production crew members have stated that Mr. Krabs was once married to a whale who gave birth to Pearl. A trivia book penned by former "SpongeBob" writer David Fain in 2000 states that Pearl "takes after her mother," implying that she is the biological offspring of Mr. Krabs and a whale. According