Largest organisms photosynthetic unicellular and multicellular protists that are related to land plants. The thallus of the unicellular mermaid's wineglass, "Acetabularia", can grow to several inches (perhaps 0.1 to 0.2 m) in length. The fronds of the similarly unicellular, and invasive "Caulerpa taxifolia" can grow up to a foot (0.3 m) long. A member of the order Cetacea, the blue whale ("Balaenoptera musculus"), is thought to be the largest animal ever to have lived. The maximum recorded weight was 190 metric tonnes for a specimen measuring , whereas longer ones, up to , have been recorded but not weighed. The African bush
Animal welfare in the United States Animal welfare is concerned with the humane treatment of animals but does not oppose all uses of animals, while animal rights is concerned with ending all human use of animals. The largest American animal nonprofit, The Humane Society of the United States (HSUS), is an animal welfare organization. PETA, Farm Animal Rights Movement (FARM), and Direct Action Everywhere (DxE) are animal rights organizations based in the U.S. The activities of animal welfare and rights organizations include lobbying for animal protection legislation and better corporate animal welfare policies (e.g. cage-free egg campaigns), promoting reductions in animal product consumption, and conducting undercover