On the ecological role of Copepoda in the Suez Canal marine ecosystem
AbstractSpecies-specific abundance of copepods was determined at monthly intervals at 10 stations in the Suez Canal water between June 1994 and May 1995. Sampling stations were chosen to represent different environmental conditions and human activities along the navigational path-way of the canal. A total of 24 copepod species belonging to 17 genera within the orders: Calanoida, Cyclopoida and Harpacticoida were recorded in the present investigation. The densities of total copepods in the surface layer (0-5 m) were higher than those in the sub-surface (5-10 m) and near bottom layer (10-15 m). Copepod nauplii and copepodites formed 22 % and 58 % of the total copepod counts, while the rest comprised the adult copepods. In the Suez Canal, only 3 species formed the main bulk of copepods, namely: Oithona nanan (Giesbrecht), Paracalanus crassirostris (Dahi) and Euterpina acutifrons (Dana) and with an average of 5590, 438 and 496 ind. M-3, respectively. There was a seasonal cycle with low winter and high summer abundance in the canal water. The copepod community of the Suez Canal is characterized by low species diversity. The inverse relationship observed between equitability and the magnitude of standing crop of copepods was discussed. Moreover, the importance of copepods in the marine food web and secondary productivity in the canal water, as well as their response to environmental variations in the Suez Canal ecosystem were discussed.
KEY WORDS: Zooplankton, Copepoda, food web, marine ecosystem, Suez Canal
Egyptian Journal of Biology Vol.3(2) 2001: 116-123