Vital fluorescent staining for non–destructive studies of neuromast topography in urodele amphibians

Abstract

Neuromasts are mechanosensory organs found in primarily aquatic vertebrates, including many species of amphibians, and are arranged as specific patterns to form the lateral-line system on the head and along the body. We used a hair-cell-specific fluorescent dye, DiASP, to analyze the distributional pattern of neuromasts in the lateral line system of live captive-born larvae of the Italian crested newt, Triturus carnifex (Laurenti, 1768). We confirmed that DiASP presents a safe and accurate alternative method for non-destructive studies of neuromast ontogeny and distribution in live amphibians. All newt larvae subjected to analyses survived and no teratogenic effects of DiASP on their further development were observed. We were able to use these data to completely characterize the distribution of neuromasts in this species and to infer the functional significance of this distribution. Cross-species comparison of general topography points to neuromast arrangement as a conserved trait in urodelans.