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Examples are swordfish, seals and gannets. Apex predators, such as orcas, which can consume seals, and shortfin mako sharks, which can consume swordfish, make up a fifth trophic level. Baleen whales can consume zooplankton and krill directly, leading to a food chain with only three or four trophic levels.
The mean trophic level is calculated by assigning each fish or invertebrate species a number based on its trophic level.The trophic level is a measure of the position of an organism in a food web, starting at level 1 with primary producers, such as phytoplankton and seaweed, then moving through the primary consumers at level 2 that eat the primary producers to the secondary consumers at level ...
The swordfish (Xiphias gladius), also known as the broadbill [5] in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood.
The main reason for this behavior is thought to be to escape from underwater predators, [3] [4] [5] which include swordfish, mackerel, tuna, and marlin, among others, [6] though their periods of flight expose them to attack by avian predators such as frigate birds.
An example, which has caused much trouble in Maryland and Florida, is the snakehead fish. [ 5 ] Predatory fish such as sharks , billfish , dolphinfish and tuna form a part of the human diet and are targeted by fisheries , but they tend to concentrate significant quantities of mercury in their bodies because they are high in the food chain ...
The sighting was made off the coast of western Australia, the charter boat company said.
The bigfin reef squid eats a variety of different marine organisms. Its main prey are usually prawns and other crustaceans, and fish. [33] Captive specimens were observed to consume one fish every 2 to 25 hours. [28] Bigfin reef squids are, in turn, preyed upon by tuna, marlin, swordfish, and other predator fish and groundfish. [34] [35]
But the predator worms were a key part of the ecosystem 518 million years ago that scientists didn’t even know existed until they found the fossils. A study describing the findings published ...