Fabienne,

A relatively easy way to label the diet is to purchase inriched forms of
15N and 13C (in the form of ammonium nitrate and sodium bicarbonate,
respectively).  The higher level of enrichment by spiking the food may
ensure a more pronounced signature shift given the trophic efficiency of
10-30% (?) from enriched nutrients to phytoplankton, then from
phytoplankton to amphipod/crustacean.

I am just starting to run 13C and 15N enrichment experiments to measure
turnover rates in the littoral copepod Acartia clausii.  Specifically,
I am measuring the turnover in adults (males and females separately,
including released eggs), that have been grown on enriched and depleted
phytoplankton (using the method above).  Since we are going through this
at about the same time I would be most interested in your progress.

Best Fishes,

Todd


Todd W. Miller
Cooperative Institute of Marine Resource Studies (CIMRS)
Oregon State University
Hatfield Marine Science Center
2030 South Marine Science Dr.
Newport, Oregon  97365 USA
ph 541-867-0397
fax 541-867-0138
[log in to unmask]

----- Original Message -----
From: Fabienne Nyssen <[log in to unmask]>
Date: Thursday, October 4, 2001 3:19 am
Subject: [ISOGEOCHEM] about 13C and 15N labelled diet

> Dear Listmembers,
>
> I work with crustaceans (and amphipods in particular) and I'd like to
> determine tissular turnover of species displaying different
> feeding type. I
> read a lot about experiments using C3 and C4 plants to trace the
> carbon but
> I wonder how to label other type of food to obtain diet enriched
> in 13C or
> in 15N (to conduct experiments with carnivores or scavengers for
> example).If you have any reference on this topic, or any
> experience you're ready to
> share, please let me know  !
> Thanks a lot for your help
> Regards
> Fabienne
>
> *******************************************************
> Fabienne Nyssen
> Institut Royal des Sciences Naturelles de Belgique
> Rue Vautier, 29
> B-1000 Bruxelles
> Tél: 02/6274460
> Fax: 02/6274277
> http://www.naturalsciences.be/general/section
> ************************************************