Baltic Sea as species in 2005 and 2018 respectively, having formerly been confused with more widespread relatives. The tiny Copenhagen cockle ("Parvicardium hauniense"), a rare mussel, is sometimes considered endemic, but has now been recorded in the Mediterranean. However, some consider non-Baltic records to be misidentifications of juvenile lagoon cockles ("Cerastoderma glaucum"). Several widespread marine species have distinctive subpopulations in the Baltic Sea adapted to the low salinity, such as the Baltic Sea forms of the Atlantic herring and lumpsucker, which are smaller than the widespread forms in the North Atlantic. A peculiar feature of the fauna is that it contains a
Broadnosed pipefish Broadnosed pipefish The broadnosed pipefish ("Syngnathus typhle") is a fish of the family Syngnathidae (seahorses and pipefishes). It is native to the Eastern Atlantic from Vardø in Norway, Baltic Sea (north to the Gulf of Finland) and the British Isles at north to Morocco at south. It is also found in the Mediterranean Sea, Black Sea and Sea of Azov. It is common in the coastal shallow waters, usually on reefs with seagrasses. This species is notable for its "broad" snout, which is as deep as its body. The broadnosed pipefish is a slender, elongated fish with a hexagonal cross-section