When DNA Tells the Tale: High-Resolution Melting as a Forensic Tool for Mediterranean Cetacean Identification

TL;DR

This paper introduces a cost-effective DNA method to identify four endangered Mediterranean cetacean species using high-resolution melting analysis, which is faster and more portable than traditional methods.

Contribution

A novel HRM-based protocol for rapid and accurate identification of four Mediterranean cetacean species using mitochondrial DNA.

Findings

The HRM protocol achieved a success rate of over 95% in identifying cetacean species from tissue and fecal samples.

Species-specific melting profiles were clearly distinguishable for Tursiops truncatus, Stenella coeruleoalba, Physeter macrocephalus, and Balaenoptera physalus.

Abstract

Effective species identification is crucial for the conservation and management of marine mammals, particularly in regions such as the Mediterranean Sea, where several cetacean populations are endangered or vulnerable. In this study, we developed and validated a High-Resolution Melting (HRM) analysis protocol for the rapid, cost-effective, and reliable identification of the four representative marine cetacean species that occur in the Mediterranean Sea: the bottlenose dolphin (Tursiops truncatus), the striped dolphin (Stenella coeruleoalba), the sperm whale (Physeter macrocephalus), and the fin whale (Balaenoptera physalus). Species-specific primers targeting mitochondrial DNA regions (cytochrome b and D-loop) were designed to generate distinct melting profiles. The protocol was tested on both tissue and fecal samples, demonstrating high sensitivity, reproducibility, and discrimination power. The results confirmed the robustness of the method, with melting curve profiles clearly distinguishing the target species and achieving a success rate > 95% in identifying unknown samples. The use of HRM offers several advantages over traditional sequencing methods, including reduced cost, speed, portability, and suitability for degraded samples, such as those from the stranded individuals. This approach provides a valuable tool for non-invasive genetic surveys and real-time species monitoring, contributing to more effective conservation strategies for cetaceans and enforcement of regulations against illegal trade.

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