Abstract
Numerous species of radiolaria were encountered in stratified plankton collections from selected western and northern Norwegian fjords during three cruises in summer and late fall of 1982 and early fall of 1983. There were clear differences between Sognefjorden and Hardangerfjorden. A new morphotype of the nassellarian Amphimelissa setosa, and the phaeodarian Borgertella caudata were essentially restricted to Sognefjorden where they dominated the summer radiolarian plankton. Certain species; Amphimelissa sp., Borgertella caudata, Cladococcus viminalis, Hexacontium enthacanthum, and Gonosphaera primordialis peaked in their abundance in the shallow zones in the upper reaches of the fjord, whereas others such as Rhizoplegma boreale and Medusella arcifera were more abundant in deep zones near the sill. This suggests a shallow native fauna found far up in the fjord and a deep recruited fauna near its entrance. Amphimelissa sp. appears to reproduce in the inner area of Sognefjorden.
In the northern fjords, Balsfjorden and Malangen, the fauna was much less diverse than that in the western fjords. It was almost totally dominated by the nassellarian Plagiacantha arachnoides. Amphimelissa sp. and Lithomelissa setosa, which were most important in the west, were consistently present but only in low abundance in the north.
Within the constraints of the sample set seven different assemblages were primarily associated with the various deep and shallow environments for each season sampled in each of the major fjord areas studied.
