YIN, M.*; YANCEY, P.H.: Methylamine Osmolytes Dominate in Deep-Sea Polychaetes, Pycnogonids, and Octopods

Osmolytes of shallow-water marine invertebrates are usually free amino acids such as glycine, alanine, taurine. Recently we showed that some deep-sea crustaceans and molluscs are dominated by trimethylamine oxide, which can offset inhibition by pressure. Echinoderms and gastropods were dominated by scyllo-inositol, whose compatibility properties are unknown. We have continued analysis other deep-sea invertebrates, using HPLC. The following analyses note solutes that were 50 mmol/kg or greater, thus providing high osmotic pressure. Arm muscles of cirrate octopods (two species) were dominated by betaine (trimethylglycine) and taurine. Body wall and muscles of polychaetes (two species: sea mouse, and Travisia) were dominated by sarcosine (methylglycine), betaine and scyllo-inositol; and leg muscles of one pycnogonid species contained mainly sarcosine. Methylamines may serve as pressure-counteracting solutes. To our knowledge sarcosine has not previously been reported at such high levels in any animal. Supported by the National Science Foundation and M.J. Murdock Charitable Trust.