Uptake of dissolved organic matter by ephyrae of two species of scyphomedusae

Abstract

Ephyrae of Aurelia labiata given dissolved organic matter (DOM) in seawater had higher carbon content than starved ephyrae. DOM-fed ephyrae of Chrysaora colorata did not have significantly higher carbon content than starved ephyrae, although the mean trend was higher. DOM-fed ephyrae of A. labiata developed aberrant morphologies similar to starved ephyrae, and neither starved nor DOM-fed ephyrae of either species developed into medusae. In addition to higher carbon content, there was evidence for DOM utilization by A. labiata shown through uptake of and increased ammonium production after exposure to a fluorescently labeled lysine polymer.