Fauna of Europe of the Baltic Sea has led to the evolution of many slightly divergent species, such as the Baltic Sea herring, which is a smaller variant of the Atlantic herring. The most frequent benthic species are "Saduria entomon" and "Monoporeia affinis", which is originally a freshwater species. A great part of its bottom is anoxic and without animal life. The Baltic Sea and North Sea are also home to a variety of marine mammals (common seals, grey seals). Europe contains several important freshwater ecoregions, including the heavily developed rivers of Europe, the rivers of Russia, which flow into the Arctic, Baltic,
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