On the occurrence of a possible bioconversion of linolenic acid into docosahexaenoic acid by the copepod Eucyclops serrulatus fed on microalgae

Reared in fertilized basins, Eucydops serrulatus appeared to be able to biosynthesize 22:6ω3 from dietary 18:3ω3. The development of zooplanktonic biomass, strongly dominated by Eucydops, coincided with the occurrence of a Chlorophycean bloom. Zooplankton phospholipids were rich in 22:6ω3 (14.5–25.9% of total fatty acids), while this fatty acid was lacking in grazed Chlorophyceae. On the other hand, Chlorophyceae contained high proportions of 18:3ω3. This last fatty acid was possibly bioconverted into 22:6ω3 and incorporated in the phospholipids of E.serrulatus.