Environmental DNA Detects Endangered Texas Hornshell and Its Hosts

Area of Science:

• Aquatic ecology
• Conservation genetics
• Molecular ecology

Background:

• Freshwater mussels (unionids) are among North America's most imperiled aquatic species.
• Traditional survey methods struggle to detect rare, cryptic, and low-density mussel populations.
• Mussel population persistence depends on the presence of viable fish host species.

Purpose of the Study:

• To develop novel quantitative PCR (qPCR) assays for detecting the endangered Texas hornshell (Popenaias popeii).
• To develop qPCR assays for two critical fish host species: gray redhorse (Moxostoma congestum) and blue sucker (Cycleptus elongatus).
• To provide improved tools for monitoring and conserving imperiled freshwater mussels and their hosts using environmental DNA (eDNA).

Main Methods:

• Development of species-specific quantitative PCR (qPCR) assays.
• Validation of assays using environmental DNA (eDNA) samples from streams.
• Focus on detecting endangered unionids and their associated fish species.

Main Results:

• Novel qPCR assays were successfully developed for the Texas hornshell, gray redhorse, and blue sucker.
• The developed assays demonstrated high sensitivity and species specificity.
• eDNA samples collected from streams were used to validate the effectiveness of the assays.

Conclusions:

• The novel qPCR assays provide effective tools for detecting and monitoring imperiled freshwater mussels and their fish hosts.
• Environmental DNA (eDNA) offers a powerful alternative to traditional methods for surveying rare aquatic species.
• These tools can significantly aid conservation efforts for vulnerable unionid populations and their ecosystems.