Growth and Survival of Larval Herring (Clupea harengus) in Relation to Prey Density

Abstract

Growth and survival rates were determined for 4- to 12-wk-old herring larvae (Clupea harengus) reared at prey densities of 0.03, 0.1, 0.3, 1.0, and 3.0 Artemia nauplii/mL. The time required for food to pass through the gut in relation to prey density was also estimated.The results indicate that significant deleterious effects occur when larvae are reared at the two lowest prey densities. Survival was reduced at 0.03 Artemia/mL and growth was lowered at 0.03 and 0.1 Artemia/mL. Growth depensation leading to size hierarchies was not correlated with prey density. Food passed through the gut more rapidly at high prey densities. The threshold prey density above which changes in numbers of prey have little effect on survival or growth was estimated to lie between 0.1 and 0.3 Artemia/mL, possibly near 0.17 Artemia/mL.Key words: fish larvae, herring, feeding ecology, predator-prey