Swimming performance of juvenile sprat, Sprattus sprattus L., and herring, Clupea harengus L., at different salinities

Sustained swimming performance of juvenile sprat, S. sprattus (29–48 mm s.l.), and herring, C. harengus (46–58 mm) was measured in a laboratory flume over a range of salinities from 18 to 33%0 at water temperatures of 16–19°C. Critical swimming speeds (CSS) of both species, relative to body length, were similar, averaging 10–12 body lengths per second (bl s^?1). There was no apparent relationship with salinity.
These swimming speeds are higher than values generally quoted in the literature for sustained swimming of sprat and herring (2–7 bl s^?1) and it is concluded that the better performance found in this study was a function of improved fish handling techniques, and of the size of fish used since most other studies have dealt with larger, commercial sized fish.