eDNA-based detection of invasive South American loricariid catfishes (Pterygoplichthys spp.) in upper tributaries of Krishna River system, India

Year 2026, Volume: 41 Issue: 1, 49 - 54, 20.01.2026

Pradeep Kumkar , Chandani Verma , Snajay Kharat , Tushar Khare , Lukáš Kalous

https://doi.org/10.26650/ASE.2026.1751186

https://izlik.org/JA38SJ87MP

Abstract

The invasiveness of the fishes in the genus Pterygoplichthys poses a considerable environmental threat to native aquatic ecosystems worldwide. This disruption of natural biodiversity and fish ecosystems corresponds to changes in nutrient dynamics resulting from the impact of Pterygoplichthys, exploitation of benthic resources, and increased interspecific competition. Fish species from this genus have been reported from various places, including the Indian subcontinent. The present study aims to develop a rapid eDNA-based assay to detect the presence of Pterygoplichthys in the Bhima River, one of the major tributaries of the Krishna River system, located in the biodiverse northern Western Ghats of India. The qPCR method was optimised with newly designed Pterygoplichthys-specific primers. Subsequently, eDNA samples collected from the seven locations were analysed under these conditions. This advanced and suitable method can be applied in other regions of India as well as in neighbouring countries where an invasion is suspected or has already occurred. Our results confirmed the presence of Pterygoplichthys eDNA in four of the seven sites. This indicates the ongoing invasion throughout the region, which is one of the global freshwater eco-regions characterized by a high degree of endemism.

Keywords

Environmental DNA , Invasion , Bhima River , Quantitative PCR , Western Ghats

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