Effect of food preservation on the grazing behaviour and on the gut flora of the harpacticoid copepod Paramphiascella fulvofasciata
Cnudde, C.; Willems, A.; Van Hoorde, K.; Vyverman, W.; Moens, T.; De Troch, M. (2013). Effect of food preservation on the grazing behaviour and on the gut flora of the harpacticoid copepod Paramphiascella fulvofasciata, in: Cnudde, C. Trophic ecology of intertidal harpacticoid copepods, with emphasis on their interactions with bacteria = Trofische ecologie van intertidale harpacticoide copepoden, met de nadruk op hun interacties met bacteriën. pp. 149-160 In: Cnudde, C. (2013). Trophic ecology of intertidal harpacticoid copepods, with emphasis on their interactions with bacteria = Trofische ecologie van intertidale harpacticoide copepoden, met de nadruk op hun interacties met bacteriën. PhD Thesis. Ghent University (UGent): Gent. ISBN 9789090278285. 209 pp., more | |
Keywords | Fecal pellets Feeding > Artificial feeding > Selective feeding Bacillariophyceae [WoRMS]; Harpacticoida [WoRMS] Marine/Coastal | Author keywords | Preserved diatoms; Bacterial community composition |
Abstract | Harpacticoids owe their ‘reputation’ as primary consumers in aquatic food webs to their substantial grazing on diatoms, thus assuring an efficient energy flow to higher trophic levels. Due to the complex feeding behaviour of harpacticoids, the nature and dynamics of diatom-harpacticoid trophic interactions remain poorly understood. In addition, there is a growing interest from aquaculture industry in mass-culturing harpacticoids with algal foods but the labour costs of maintaining algal stock cultures are high. This study focuses on the palatability of preserved diatoms for copepods and considers the possible role of bacterial mediated effects on diatom food uptake.The grazing of Paramphiascella fulvofasciata on a preserved freeze-dried diatom diet was tested and compared to the grazing on fresh cells. P. fulvofasciata assimilated the preserved diet, but assimilation of fresh cells was higher. When both cell types were mixed, no selective feeding was observed. Community fingerprinting of the bacteria associated with diatoms and fecal pellets suggests that the copepod gut flora was modified depending the food source. Furthermore, the results suggest that the egestion of gut bacteria enriches the microenvironment and this can have an additional influence on the feeding behaviour of the copepod.Experimental research using preserved foods must take into account that copepod grazing assimilations of fresh foods are likely to be significantly higher. Yet, the stated high assimilation of the mixed diet, encourages further exploration of the application of preserved balanced foods for harpacticoid mass-culturing. |
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