Exploratory environmental DNA analysis for investigating plant-feeding habit of the redeared turtle using their feces samples

Abstract

Exploratory environmental DNA, eDNA analysis was performed to investigate plant- feeding habits of the red-eared turtle using their feces samples. This turtle species non- native to Japan appears to be causing feeding damage to lotus roots in several rural areas as a pest, although the reality is still unproven scientifically. The feces samples were collected from five turtles inhabiting agricultural canals surrounding lotus root paddies in Tokushima Prefecture where feeding damage has arisen. After eDNA extraction from the feces samples and polymerase chain reaction, PCR amplification, electrophoresis and sequencing analysis of the amplified PCR products were carried out to confirm whether chloroplast DNA fragments of seven targeted plant species including the lotus were detected from the eDNA samples. From the results, the DNA fragments of six plant species were detected from all eDNA samples, hence, this eDNA analysis appeared to be successful. It suggested that the number of the detected plant species differed between young and adult turtles. Different habitats of the detected plant species indicated that the turtles migrated between the lotus root paddies and the canals. The lotus DNA fragments were found in all turtles. Therefore, our eDNA analysis helps to more definitely prove the feeding damage of the lotus root by this turtle.