Jt. Lehman, EFFICIENCIES OF INGESTION AND ASSIMILATION BY AN INVERTEBRATE PREDATOR USING C-DUAL AND P-DUAL ISOTOPE LABELING, Limnology and oceanography, 38(7), 1993, pp. 1550-1554
Daphnia rosea was uniformly labeled with both C-14 and P-33, then offe
red as prey to Bythotrephes cederstroemi Schoedler, a nonindigenous pr
edatory cladoceran which has become established in the Laurentian Grea
t Lakes. Both C and P from the prey were ingested with equal efficienc
y (58-59%, SE = 2%) by Bythotrephes and retained with equal efficiency
over the next 12 h. Feeding behavior by the predator involves a fasti
dious process of shredding and discard of exoskeletal material and sel
ective ingestion of soft tissue. Most of the ingested matter is conseq
uently digested; assimilation efficiency is 85% (SE = 2%).