Changes in lipids during simulated herbivorous feeding by the marine crustaceanNeomysis integer

Abstract

A laboratory study simulating herbivorous feeding was carried out with the marine crustacean Neomysis integer (Leach) and the dinoflagellate Scrippsiella trochoidea (Stein). Analyses of the total fatty acids, sterols and fatty alcohols in the food and faecal material, and in the animal tissue, have allowed the detailed changes in the dietary lipids during feeding to be characterised.The results show this feeding leads to a net decrease in total lipid in the material passing through the gut of the animal, particularly due to the bioassimilation of fatty acids. All fatty acid saturation classes are assimilated but the mono-unsaturated and particularly polyunsaturated fatty acids are preferentially assimilated over others. Herbivorous feeding does, however, lead to the quantitative and relative increase in ‘bacterial’-type odd C number branched-chain fatty acids in the faecal material.

Reviews and syntheses: to the bottom of carbon processing at the seafloor

“…Detailed investigations of organic matter composition might in principle resolve this issue as microbial and animal processing of organic matter results in the formation of distinct compounds (Bradshaw et al, 1990;Sun et al, 1999;Thomas and Blair, 2002;Woulds et al, 2012Woulds et al, , 2014. There are a few issues with this approach: (1) most sedimentary organic matter is molecularly uncharacterizable and the origin (imported from the water column vs. newly produced within the sediment) can thus not directly be investigated, (2) microbes living within (the guts) of animals may mask the animal signatures (Woulds et al, 2012(Woulds et al, , 2014 and (3) different analytical windows (amino acids vs. lipids) may result in different inferences.…”

Intense photooxidative degradation of planktonic and bacterial lipids in sinking particles collected with sediment traps across the Canadian Beaufort Shelf (Arctic Ocean)

“…The presence of relatively high proportions of these degradation products of the chlorophyll phytyl side-chain well supports the contribution of zooplanktonic faecal pellets to the sampling material. Indeed, pelagic crustaceans decrease the abundance of the chlorophyll phytyl side-chain when feeding herbivorously (Prahl et al, 1984;Harvey et al, 1987;Bradshaw et al, 1990). Any phytol remaining in the faeces of pelagic zooplankton after herbivorous feeding will be quickly removed on subsequent reprocessing of the faecal material (Bradshaw and Eglinton, 1993).…”

Dietary lipid changes during herbivory and coprophagy by the marine invertebrate Nereis diversicolor

“…Neomysis was collected from the Tamar estuary and maintained as described previously (Bradshaw et al, 1990). Nereis was collected from mud flats at Saltram Beach on the Plym estuary and maintained at the laboratory in a portion of mud from the estuary under a constant flow of pumped unfiltered sea water.…”

“…As in other experiments using the alga Scrippsiella as the primary food source (Bradshaw et al, 1990, in preparation), quantitation of lipids is based on the internal quantitative marker 4oc,23R,24R-trimethylcholestan-3P-ol (dinostanol) present in the alga (Bradshaw et al, 1990). The reasons for the use of this marker are discussed elsewhere (Bradshaw et al, 1989).…”

“…Our knowledge concerning the manner in which marine invertebrates alter the lipids in marine food chains and thus influence sedimentary lipid distributions has until recently been limited to studies of mainly pelagic crustacean feeding (Volkman et ah, 1980a;Prahl et al, 1984a, b;Harvey et ah, 1987;Bradshaw et a\., 1990). While this animal group is undoubtedly important in the processing of primary production in the water column, other important groups such as the molluscs, annelids and echinoderms must also have some effect upon the lipids in food chains through their own lipid metabolisms.…”