Respiration and nitrogen excretion by the squid Loligo forbesi

The amphipod Corophium volutator (Pallas) of the Bay of Fundy is a major food resource for migrating shorebirds. A relatively low total lipid content (ca 1.7%) was found in summer and fall samples of 1986. Analysis of triacylglycerides which would normally reflect an animal diet through fatty acid input, revealed high proportions of fatty acids characteristic of algae. C. volutator contains hydrocarbons (0.2% of total lipids) with a unimodal distribution in the range C₁₈ to C₃₅ with maximum at C₂₅, and a weak odd-carbon preference (carbon preference index, C.P.I. =1.22). This hydrocarbon pattern shown by C. volutator seems to be biogenic, but due to both a weak odd-carbon preference and a significant content of the isoprenoid phytane, the presence of petroleum hydrocarbons cannot be ruled out. Comparison of the hydrocarbon composition be ruled out. Comparison of the hydrocarbon composition found in C. volutator with hydrocarbons described in the literature for its most likely sources of food suggests that highly degraded material and aged detritus are components of the diet of this deposit feeder, and as important as the local diatom population. No organohalogen pesticides (DDT, dichlorodiphenyl-trichloroethane, or derivatives) or polychlorinated biphenyls (PCBs) were detected in the lipid extracts of C. volutator. Absence of these materials and low hydrocarbon levels explain the continued successful exploitation of this food resource by migrating shorebirds.