A seafood is an animal whose principal habitat , the ecosystem Sea is. The term does not designate a natural kinship group ( taxon ) in the sense of biological systematics , but is a collective term for animals that belong to the marine plankton , nectons or benthons . In a broader sense, marine animals also include certain seabirds (e.g. penguins ), turtles and seals , whose young are born on land.
Many of today inhabiting the sea species did not occur there, but are descended from forms that the country (eg. As whales ) or from the fresh water (eg. As Teleostei (Teleostei)) immigrated and secondarily to a Adapted to marine life.
Of the approximately 8.7 million species of organisms , around 2.2 million are marine animals. Only 12 percent of marine animals are fish. Crustaceans make up a fifth of the species described. However, the largest proportion of living organisms living underwater are made up of marine microbes. Researchers assume that there are several billion species of microbes that have yet to be discovered. According to research, the occurrence of larger marine animal species has declined by an average of around 90 percent since recording began. The hunt for bluefin tuna in the North Sea meant that this region was fished empty in the early 1960s. The occurrence of bluefin tuna in the North Sea is still rare today. Around 100,000 marine organisms per year die on plastic waste in the oceans because they mistake the waste for food and eat it. You feel full but eventually starve to death with a garbage-filled stomach.
- Cnidarians :
- Annular worms :
- Molluscs :
- Arthropod :
- Echinoderms :
- Digital Atlas of Marine Species and Locations , Rosenstiel School of Marine and Atmospheric Science, University of Miami
- Ocean Life , Lighthouse Foundation
- Information about marine animals. das-tierlexikon.de, 2010, accessed on November 22, 2015 .
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- Kirsten Bode, Julia Kloft: Terra X: Universe of the Oceans. (No longer available online.) In: Dumbo and the Primeval Crab - The researchers of the Census of Marine Life take stock. ZDF , October 24, 2010, archived from the original on December 3, 2016 ; accessed on November 22, 2015 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- Plastic waste in the sea - facts and figures. (PDF; 289 KB) In: Wissenschaftsjahr.de. Retrieved January 14, 2019 .