Study on the feeding habit and trophic level of main economic invertebrates in the Huanghai Sea

The stomach contents of 14 main invertebrates in the Huanghai Sea are analyzed. The results indicate that:(1) the examined predator species were all omnivore with wide food range, showing no obvious selection for spacific food items, (2) on the basis of their ecological habitat, the predators could be classified into 5 different types, i. e.,benthoelagic and planktopelagic animals, nektopelagic and planktopelagic animals, benthopelagic animals, nektopelagic and benthopelagic animals, and nektopelagic animals and (3) the trophic level of the 11 predator species, including Crangon affinis, Palaemon gravieri, Penaeus orientalis, Trachypenaeus curvirostris, Metapenaeopsis dalei, Portunus trituberculatus, Charybdis bimaculata, Oratosquilla oratorio, Sepia andreana, Loligo beka and L.japonica ranged from 2.30 to 2.72, belonging to low carnivore (trophic level:2.0-2.8), whereas that of the other 3 predator species, including Sepia esculenta, Sepiella maindroni and Todarodes pacificus were in the range of 2.86-2.97, belonging to mid-carnivore (trophic level:2.9-3.4).