Uptake of Amino Acids by Three Species of Nereis (Annelida: Polychaeta). II. Effects of Anaerobiosis

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Abstract
Uptake of 3 amino acids and release of individual amino acids and ammonia were investigated in the polychaetes N. succinea, N. diversicolor and N. virens during 48 h of anoxic incubation. Uptake rates of alanine, serine and glutamic acid from 5 .mu.M solutions were reduced to 30-85% of aerobic rates by 12 h, but stabilized for the remainder of the incubation period. Net release of amino acids from N. succinea and N. virens was insignificant during the 1st 4 h of anoxia; after 12 h, amino acid release had increased in both species. During additional anoxic incubation a decrease in net release rates was found. The opposite pattern occurred in N. diversicolor. Release rates of ammonia in all 3 spp. generally demonstrated tendencies similar to amino acid release rates. This similarity in release rates over time suggests that released amino acids are also metabolic waste products. The composition of the released amino acids varied greatly during incubation and no predominant amino acids were found. The concentration of free intracellular amino acids increased in all 3 spp. during anaerobiosis; glycine and taurine were most abundant. Alanine typically increased during incubation; the concentrations of glycine and taurine showed wide fluctuations.