On the mesopelagic fish faunas of slope water, Gulf Stream, and northern Sargasso Sea

Abstract

Midwater trawl collections from north of 32°N and west of 50°W were divided on the basis of 200-m temperature into three sets: Slope Water (9° ⪯ T < 15°C) -24 collections, Gulf Stream (15° ⪯ T < 17·5°C) -7 collections, and northern Sargasso Sea ( T ≥ 17·5°C) -20 collections. A percentage similarity measure shows that the fauna of the Slope Water is distinct from those of the Gulf Stream and northern Sargasso Sea (PS= 39% and 36%, respectively) and that the Gulf Stream and northern Sargasso Sea sets are faunistically somewhat similar (PS= 57%). In a cluster analysis, the Slope Water and northern Sargasso Sea sets appear distinct, while the Gulf Stream collections show affinity with both these sets. Species, clustered according to their relative abundance in each collection, form groups which correspond more to the species' overall North Atlantic distribution patterns than to their relative abundance in the three sets.