Accession Number : AD0735568

Title :   The Succession of Two 'Podon' (Crustacea, Cladocera) Species in the North Sea,

Corporate Author : MCGILL UNIV MONTREAL (QUEBEC) MARINE SCIENCES CENTRE

Personal Author(s) : Cieskes,W. W. G.

Report Date : 1971

Pagination or Media Count : 6

Abstract : The succession of two species of Podon in the North Sea is discussed. The pioneer P. leuckarti is ecologically separated in time from the successor P. intermedius presumably because of different temperature tolerances and temperature optima of the congeners. Competitive exclusion does not take place; the smaller species, occurring in spring and early summer, is succeeded by the closely related, but larger species, living in the North Sea in the warmer summer months. It is suggested that the succession of the two Podon species is causally related with succession in food availability. P. intermedius makes its appearance in the neritic North Sea water at a higher temperature (at 13C) than in the oceanic waters of the eastern Atlantic (at 9C). This species is perhaps differently influenced by the difference in salinity between 'neritic' and 'oceanic' water. (Author)

Descriptors :   (*CRUSTACEA, *NORTH SEA), (*ECOLOGY, CRUSTACEA), MARINE BIOLOGY, DISTRIBUTION, CLIMATOLOGY, TEMPERATURE, OCEANS, AQUATIC ANIMALS, CANADA

Subject Categories : Biological Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE