Uptake of naturally occurring primary amines by marine annelids

TLDR: The present contribution provides direct evidence for a rapid net influx of naturally occurring organic material and amino acids in two genera of the annelid infauna and stimulation of production of available organic compounds in sediments as a result of the presence and activity of the Annelid Infauna.

Abstract: Rapid, carrier-mediated influx of small organic molecules across the body wall of marine invertebrates has been studied by a number of investigators. Recent literature is reviewed by Stephens ( 1972) who interprets available evidence as supporting a net influx which is large enough in many instances to represent a significant supplement to the nutrition of the animals concerned. This interpre tation has been questioned by Johannes, Coward and Webb ( 1969) . These investi gators studied exchanges of amino acids between the flatworm, Bdelloura, and the environment and found a net efflux. Stephens and Schinske ( 1961 ) studied net exchanges of amino acids in a wide range of invertebrate material and reported a net influx. These results can be reconciled by noting the very different ambient concentrations used by the two sets of investigators and the relative insensitivity of efflux to changes in ambient concentration (as argued in Stephens, 1972) . How ever, this analysis is somewhat indirect since it is based on separate measurements of influx and efflux using labelled substrates. The present contribution provides direct evidence for a rapid net influx of naturally occurring organic material and amino acids in two genera of the annelid infauna. A fundamental gap in the literature concerning transepidermal uptake is the failure to establish any convincing link between this process and a quantitatively tenable source of available organic compounds in the environment. Speaking more generally, transepidermal uptake needs to be integrated into the general trophic structure of marine communities in order to aspire to a status other than that of an interesting curiosity of unknown significance. The present contribution also reports stimulation of production of available organic compounds in sediments as a result of the presence and activity of the annelid infauna. This represents the requiredlinkagebetweenuptakeandproduction andisan initial stepinthedesired integration of the process into the overall trophic structure of the community. This work was greatly faciliated by the introduction of a new reagent, fluores