Stepping inside a dried seafood merchant in Singapore, an unsuspecting shopper might easily overlook packets simply labeled as fish gills. This mundane phrasing hides a startling reality: these dried goods stem from some of the ocean's most vulnerable creatures. Investigators tracking wildlife commerce in the city-state sought to uncover the truth behind this obscure market, revealing an opaque supply chain intersecting consumer demand, biodiversity loss, and global trade laws.

The High Price of Filter Feeders

The animals in focus are mobulids—manta and devil rays. These iconic, shark-related swimmers use specialized gill rakers to strain tiny plankton from the sea. Unfortunately, these exact anatomical structures fuel a lucrative demand within Asian traditional medicine and dried seafood sectors. Vendors market them under names like peng yu sai, claiming unproven benefits ranging from circulation enhancement to cancer treatments. Scientific analysis counters these claims, frequently detecting toxic heavy metals like arsenic, lead, and mercury within the products.

Alarming Conservation Realities

Mobulid reproduction rates are exceptionally slow, with females yielding merely one pup every two to five years. Fisheries pull roughly 264,000 of these rays annually, driving regional population drops of up to 99%. Despite these alarming trends, the specific species entering international commerce remained poorly understood, particularly within vital transit hubs like Singapore.

DNA Barcoding Unveils the Catch

Between February and March 2026, scientists surveyed 20 retail shops and a wholesaler across Singapore, gathering 439 samples of dried gill rakers priced between $14 and $470 USD per kilogram. Because processing strips away distinguishing physical traits, researchers deployed DNA barcoding to decode the genetic identity of the items.

  • Every successfully identified sample originated from a manta or devil ray.
  • Five distinct species emerged, heavily dominated by the Spinetail Devil Ray and the Sicklefin Devil Ray.
  • Critically endangered species constituted approximately 80% of the identified samples.
  • Altogether, 84% of verified specimens traced back to critically endangered classifications.

Regulatory Loopholes and Transparency Gaps

Although some merchandise claimed origins in India, researchers found zero matching records in international CITES databases. Official logs recorded merely two commercial mobulid gill raker permits involving Singapore from 2016 to 2025. Vague labeling practices like fish gills obscure regulatory oversight, highlighting severe transparency vulnerabilities within the supply chain.

A Turning Point for Global Protections

This investigation coincides with a pivotal milestone: in March 2026, all ten mobulid species gained stringent protections under Appendix I of CITES, banning international commercial trade. While these heightened safeguards simplify enforcement, their success hinges strictly on rigorous monitoring, precise paperwork, and proactive oversight. This study establishes a vital baseline to measure future shifts in the regional trade and safeguard these majestic ocean dwellers from extinction.