Hi, I am currently running my very first Enchytraeid extraction :-) (O' Connor) and was wondering how long I can store the extract (water) before counting? I assume its easiest to count enchytraeids when they are still alive? Thanks for your advice!
Enchytraeid species are easiest to identify alive, but counting can be done on fixed material, e.g. ethanol. Usually the worms survive at least a week in water if you keep the samples cool (5-10 degrees C), but I have had worms survive as long as six months in water with a little debris at the bottom (so not distilled water!). Good luck!
Heidi is right. Some benthic samples with the organisms that are not very sensitive to temperature changes can store week or more under low temperature in refr., but it also depends on generative abilities of the organisms. General theory says that metabolism falling with temperature has coefficient 2,25 times per 10 degrees (this is equation of Vant-hoff & Arrenius) so you can slightly recalculate when will appear sensitive mistake...
Anyway better to store in community, as monocultures can produce even cannibalistic forms, what is known for ciliated Protozoa. For detrivorous worms may be it isn't problem.