Production of Aldehydes in Diatoms and Dinoflagellates and the Detrimental Effect on Copepod Grazers
Li, J.; Wang, Y.; Liang, Y.; Huang, J.; Liu, Y.; Lu, J.
International Journal of Agriculture and Biology 22(4): 763-768
Marine algae, including diatoms, are the primary food source of oceanic ecosystems, sustaining the marine food chain to top consumers and playing a key role in marine food webs. Their beneficial role is questioned due to the finding of harmful compounds in their secondary metabolites, such as polyunsaturated aldehydes, which impair reproductive and developmental processes of their grazers. To investigate the response of dominant copepod grazers in the Jiaozhou Bay to different diets and how aldehydes vary in batch algal cultures over time, we carried out experiments in which two diatoms Skeletonema marinoi and Chaetoceros didymus were fed to the copepod Calanus sinicus. Controls were run with two dinoflagellates Prorocentrum micans and Scrippsiella trochoidea. In our two set of experiments, we found a C(7)saturated aldehyde released by those four algal species, which is less reported. Our results showed that diatoms have greater potential for aldehydes production than dinoflagellates and the peak of aldehydes production occurred mostly in the first and second week, which clearly includes lag and exponential phase. However, the detrimental effect on copepods was species dependent. Some dinoflagellates are also potential aldehydes producers. Even though some dinoflagellates released fewer aldehydes than diatoms, the inhibitory effect on copepods was greater.