Anithmanion sparsum is a red alga, native to the Northwest Pacific, from southern Pacific Russia to South Korea. In 2021, this seaweed was identified on rocky shores near Halifax, Nova Scotia, using molecular merthods (Brooks and Krumhisel 2023). It grows as branched fine filaments, growing as a turf about 30 mm tall. The extent of its invasion is uncertain because of similarity to the introduced (A. hubbsi = A. nipponicum?) and the native (A. cruciatum).