The Molting Biomarker Metabolite N-acetylglucosamino-1,5-lactone in Female Urine of the Helmet Crab Telmessus cheiragonus

N-acetylglucosamino-1,5-lactone (NAGL) is a molting biomarker in the blue crab Callinectes sapidus. The concentration of this compound in urine is highest at the premolt stage. Since sexually mature premolt females release sex pheromone in their urine, NAGL is a candidate sex pheromone molecule in C. sapidus. This compound has not been reported in other species. In the present study, we quantified the concentration of NAGL in the urine of the helmet crab Telmessus cheiragonus, using nuclear magnetic resonance spectroscopy, and found that the concentration increases toward the day of molting and decreases after molting. However, the total amount of NAGL collected from individual animals was greatest two to five days after molting, because the amount of urine collected was the lowest at the premolt stage, and it increased after molting. The highest median concentration of NAGL in T. cheiragonas was 29 μmol 1–1, which is 75% of the highest concentration reported in C. sapidus. This is the first report of NAGL as a molting biomarker in a species other than C. sapidus. We assume that NAGL is part of a pheromone bouquet in these two species.