DNA barcoding to assess diet of larval eastern hellbenders in North Carolina

Abstract

Freshwater macro-invertebrates are integral components of stream ecosystems, for example, as prey for many aquatic vertebrates. Identification of smaller aquatic macro-invertebrate prey items presents challenges to researchers due to size, taxonomic skill required to properly classify species, or lack of complete diet specimens. Therefore, many traditional methods of morphological identification may not reveal cryptic biodiversity of diet available to vertebrates, such as small larval salamanders, in lotic environments. We used DNA barcoding to identify prey items obtained from gastric lavage of ten small, larval eastern hellbender salamanders, Cryptobranchus alleganiensis, allowing for greater taxonomic resolution than in previous studies. The eastern hellbender is a species of conservation concern in many areas throughout its geographic range, with little ecological knowledge presently available for juvenile life stages. We identified twelve taxonomic groups of invertebrate prey, including Nixe spinosa, Baetis intercalaris, Baetis flavistriga, Baetis sp., Lumbriculus rubellus, Thienemannimyia sp., Perlesta nelsoni, Maccaffertium ithaca, Iswaeon anoka, Isoperla dicalas, Epeorus vitreus, and Maccaffertium pudicum. Our data illustrate the utility of this emerging, affordable method to further inform traditional food web studies which researchers can use to manage aquatic ecosystems.