salps during blooms. History The incursion of a large number of salps (Salpa fusiformis) into the North Sea in 1920 led to a failure of the Scottish herring fishery. Oceanographic importance A reason for the success of salps is how they respond to phytoplankton blooms. When food is plentiful, salps can quickly bud off clones, which graze on the phytoplankton and can grow at a rate which is probably faster than that of any other multicellular animal, quickly stripping the phytoplankton from the sea. But if the phytoplankton is too dense, the salps can clog and sink to the bottom. During these blooms, beaches can become slimy with mats of salp bodies, and other planktonic species can experience fluctuations in their numbers due to competition with the salps. Sinking fecal pellets and bodies of salps carry carbon to the seafloor, and salps are abundant enough to have an effect on the ocean's biological pump. Consequently, large changes in their abundance or distribution may alter the ocean's carbon cycle, and potentially play a role in climate change. Nervous systems and relationships to other animals Salps are closely related to the pelagic tunicate groups Doliolida and Pyrosoma, as well as to other bottom-living (benthic) tunicates. Although salps appear similar to jellyfish because of their simple body form and planktonic behavior, they are chordates: animals with dorsal nerve cords, related to vertebrates (animals with backbones). Small fish swim inside salps as protection from predators. Classification The World Register of Marine Species lists the following genera and species in the order Salpida: Order Salpida Family Salpidae Subfamily Cyclosalpinae Genus Cyclosalpa de Blainville, 1827 Cyclosalpa affinis (Chamisso, 1819) Cyclosalpa bakeri Ritter, 1905 Cyclosalpa foxtoni Van Soest, 1974 Cyclosalpa ihlei van Soest, 1974 Cyclosalpa pinnata (Forskål, 1775) Cyclosalpa polae Sigl, 1912 Cyclosalpa quadriluminis Berner, 1955 Cyclosalpa sewelli Metcalf, 1927 Cyclosalpa strongylenteron Berner, 1955 Genus Helicosalpa Todaro, 1902 Helicosalpa komaii (Ihle & Ihle-Landenberg, 1936) Helicosalpa virgula (Vogt, 1854) Helicosalpa younti Kashkina, 1973 Subfamily Salpinae' Genus Brooksia Metcalf, 1918 Brooksia berneri van Soest, 1975 Brooksia rostrata (Traustedt, 1893) Genus Ihlea Metcalf, 1919 Ihlea magalhanica (Apstein, 1894) Ihlea punctata (Forskål, 1775) Ihlea racovitzai (van Beneden & Selys Longchamp, 1913) Genus Metcalfina Metcalfina hexagona (Quoy & Gaimard, 1824) Genus Pegea Savigny, 1816 Pegea bicaudata (Quoy & Gaimard, 1826) Pegea confederata (Forsskål, 1775) Genus Ritteriella Metcalf, 1919 Ritteriella amboinensis (Apstein, 1904) Ritteriella picteti (Apstein, 1904) Ritteriella retracta (Ritter, 1906) Genus Salpa