Brachynotus sexdentatus is a species of crab in the family Varunidae. It is native to the Mediterranean Sea and Black Sea and became established for a time in Swansea Docks (United Kingdom). It grows to a maximum carapace width of 18 mm (0.71 in) and lives in shallow water on muddy bottoms. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Animal