In this study, we investigated the composition of free amino acids and lactate (Lac) in polychaetes in river estuaries and inner bays using chromatographic techniques. Both l-amino acids and d-amino acids (d-asparagine, d-alanine (d-Ala), d-serine, d-aspartic acid, and d-proline (d-Pro)) were detected, indicating that polychaetes contain some d-amino acids. Some polychaete species exhibited notable amino acid levels, such as glycine in Capitellidae sp. and Thelepus sp., d-Pro in Glycera sp., and β-Ala in Scoletoma nipponica and Scoletoma sp.. High d-Lac levels were detected in Tylorrhynchus osawai and Hediste diadroma, (691 and 797 μmol/100 g-wet, respectively), with the d-form exceeding 98%. T. osawai was dominant in the upper tidal-sensitive zone, wherein other organisms were less abundant because of low salinity (3–8 PSU). Seasonal differences in the concentrations of components in T. osawai were observed, particularly a significant increase in d-Lac in the reproductive period. Notably, the d-Lac concentrations of T. osawai were higher upstream than downstream. Thus, d-Lac might be involved in strategies underlying adaptations to low salinity and reproductive activity. These results suggest that both the d-form of Lac and amino acids may play certain physiological roles in the life of polychaetes.

在这项研究中，我们利用色谱技术研究了河口和内湾多毛类动物中游离氨基酸和乳酸 (Lac) 的组成。检测到l-氨基酸和d-氨基酸（ d-天冬酰胺、 d-丙氨酸（ d -Ala）、 d-丝氨酸、 d-天冬氨酸和d-脯氨酸（ d -Pro）），表明多毛类含有一些d-氨基酸。一些多毛类物种表现出显着的氨基酸水平，例如 Capitellidae sp. 中的甘氨酸。和Thelepus sp.、 Glycera sp. 中的d -Pro、以及Scoletoma nipponica和Scoletoma sp. 中的 β-Ala。在Tylo rhynchus osawai和Hediste diadroma中检测到高d -Lac 水平（691 和 797 μmol/100 g-湿，分别），其中d型超过98%。 T. osawai在上层潮汐敏感区占主导地位，由于盐度较低（3-8 PSU），其他生物的数量较少。观察到T. osawai中各成分浓度的季节性差异，特别是在繁殖期d -Lac 显着增加。值得注意的是， T. osawai的d -Lac 浓度上游高于下游。因此， d -Lac 可能参与了适应低盐度和繁殖活动的策略。这些结果表明，Lac 的d型和氨基酸都可能在多毛类动物的生命中发挥一定的生理作用。