An ecological study of some littoral freshwater microcrustaceans (Cladocera and Copepoda) in Newfoundland

摘要

Samples were obtained in the littoral region of 74 waters from various parts of the Province of Newfoundland and Labrador. The Cladocera and Copepoda found in the collections were listed. Sixty-two species were recorded which included 47 species of Cladocera and 15 species of Copepoda. Twenty-six species of Cladocera and 12 species of Copepoda represent new records for the Province. In addition, a new cyclopoid copepod species was described, Paracyclops yeatmani n. sp. -- A quantitative study was made of the littoral microcrustaceans in a bog pond and a marsh located on the Avalon Peninsula from May, 1972 to May, 1973. The maximum standing stocks were similar in the two localities. The dominant forms in the summer and fall in the marsh were Cladocera: Acantholeberis curvirostris, Biapertura intermedia, Chydorus sphaericus, and Ilyocryptus spinifer. In the winter the copepod, Macrocyclops albidus, was dominant, while Cyclops varicans rubellus was the most abundant species in the spring. The bog pond also was dominated by Cladocera in the summer and fall; namely; Acroperus alonoides, Alona rustica, Alonella excisa, Chydorus sphaericus, and Sida crystallina. The copepods, Eucyclops agilis and Macrocyclops albidus, were dominant in the winter and early spring. -- Qualitative seasonal succession and the relative abundance of Cladocera and Copepoda were studied in 10 waters on the Avalon Peninsula. This provided seasonal data for 38 species. Such studies showed that sampling on one date seldom revealed all species known for a particular water body. -- Plant and microcrustacean associations were investigated. The results suggest that some microcrustaceans are associated with particular plant species (or types). Also, some Cladocera may utilize particular parts of a plant. -- Observations were made on the feeding habits and predators of some littoral microcrustaceans.