Effect of algal species and concentration on development and fatty acid composition of two harpacticoid copepods,Tisbesp. andTachidius discipes, and a discussion about their suitability for marine fish larvae

Abstract

We compared the development and fatty acid content of the harpacticoid copepods Tachidius discipes and Tisbe sp. fed with different microalgal species (Dunaliella tertiolecta, Rhodomonas sp., Phaeodactylum tricornutum, Isochrysis galbana and a concentrate of Pavlova sp.), which differed in cell size and fatty acid composition. Tisbe could develop in 11 days with every alga to the same average stage, whereas Tachidius developed poorly when fed with Isochrysis and Dunaliella. Feeding with Phaeodactylum resulted in a fast development of both copepods at low algal concentrations. However, reproduction was higher with Rhodomonas as food than with the other algae. Fatty acid compositions of copepods were influenced by their food source, but both were able to convert docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from precursors. Tachidius fed with Rhodomonas or Phaeodactylum was closest to the DHA/EPA/arachidonic acid (ARA) ratio of 10 : 5 : 1 considered optimal for some marine fish larvae. Tachidius showed similar development and reproduction capacity as Tisbe, but requested higher absolute fatty acid contents in the diet. Tisbe was superior in the utilization of bacteria as additional food source and the bioconversion of precursor fatty acids. Phaeodactylum and Rhodomonas are recommendable food sources for both copepod species, but Phaeodactylum is more easily cultured.

Demography and feeding behavior of Stenostomum leucops (Dugés, 1828)

“…The highest densities of S. leucops were reached when their diet was supplemented with fresh algae but not detritus, probably because of the poor nutritional quality of the latter (Sterner and Hessen, 1994). Nutritional value of these resources is reflected in the somatic phosphorus content and composition of fatty acids (DeMott and Pape, 2005;Arndt and Sommer, 2014). Paramecium sp.…”

Transcriptome, Biochemical and Growth Responses of the Marine Phytoplankter Phaeodactylum Tricornutum Bohlin (Bacillariophyta) to Copepod Grazer Presence

“…Measurements of POC (particulate organic carbon) and PON (particulate organic nitrogen) were conducted as described in Sharp [52] by gas-chromatography in an organic elemental analyzer (Thermo Flash 2000; Thermo Fisher Scientific Inc., Schwerte, Germany). FAs were measured as fatty acid methyl esters (FAMEs) using a gas-chromatograph (Trace GC-Ultra; Thermo Fisher Scientific Inc.) according to the procedure detailed in Arndt and Sommer [53]. …”

Simultaneous shifts in elemental stoichiometry and fatty acids of <i>Emiliania huxleyi</i> in response to environmental changes

“…Feng et al (2017a) suggested that the decreased calcification in E. huxleyi may be caused by the increased requirement of energy to counteract intracellular acidification. The increased activity of carbonic anhydrase (CA) at low pCO 2 may explain the lack of a significant effect of pCO 2 on the photosynthetic or growth rate (Feng et al, 2017a), as upregulation of CA at low DIC was previously observed (Bach et al, 2013).…”