Tiny, glowing shark found in Gulf of Mexico identified as new species — the American pocket shark
Tulane University researchers have identified Mollisquama mississippiensis, the American pocket shark, a tiny bioluminescent species about 14 centimeters long found in the Gulf of Mexico, and only the second pocket shark ever described by science.
- New species: Mollisquama mississippiensis — only the second pocket shark on record.
- Size & features: ~14 centimeters long, with two luminous “pocket” glands and clusters of photophores.
- Discovery: Collected in February 2010 and identified via museum preservation, imaging and detailed study.
- Scientific value: Shows the importance of collections and modern imaging in revealing hidden deep-sea biodiversity.
Discovery and identification
Collection: The specimen was collected in February 2010 during fieldwork in the Gulf of Mexico while researchers were studying sperm whales. The tiny male shark — roughly the length of a human hand at about 14 cm — was preserved and archived in a museum collection.
Identification: Years later, Tulane scientists working with U.S. federal agency specialists examined the specimen and, using detailed external study and advanced imaging, concluded it differs from the only previously known pocket shark, Mollisquama parini (collected in 1979 off Chile).
Physical description and the glowing deep-sea feature
Appearance: The American pocket shark has a cylindrical body, a bulbous head with a wide snout, and a mouth positioned on the underside. When closed, the lower jaw’s teeth overlap the upper.
Bioluminescent adaptations: Two distinctive “pocket” glands near the gills can secrete luminous fluid; in addition, clusters of photophores appear across the body. This combination of secreted luminous fluid plus photophores is rare among sharks and likely an adaptation to the deep, dark environment.
“The pockets can produce and eject a luminous fluid; photophores also light the body — a striking suite of light-producing features for a shark this small.”
Why the shark glows
Scientists propose several hypotheses, including: luring prey, counter-illumination camouflage (matching faint downwelling light), or intraspecific communication. These remain hypotheses pending behavioral or ecological observations.
Scientific methods and rarity
Because only a single specimen of Mollisquama mississippiensis is known, researchers combined classical taxonomy with non‑destructive modern imaging: microscopic photography, X‑ray imaging and advanced CT scanning were used to reveal internal and external features without damaging the specimen. The rarity of pocket sharks is striking — the first species was collected in 1979 and preserved in a museum in Russia — making this the second recorded member of its group.
Broader scientific context
Classification: The species belongs to Dalatiidae (kitefin sharks), a family of mostly small, deep-dwelling sharks in the order Squaliformes.
Importance: The discovery underscores how much of ocean life remains undocumented and highlights the crucial role of museum collections and modern imaging technologies in taxonomy. A specimen collected in 2010 remained unstudied in a collection until the tools and expertise were available to examine it closely — a common story in modern species discovery.
Implications for the Inland Empire
Economic: Increased interest in deep-sea research can spur federal and state funding, creating opportunities for local engineering, imaging and data-analysis firms in the Inland Empire.
Political & social: The find may boost bipartisan support for STEM investments, coastal science initiatives and education pipelines at regional universities and community colleges. Outreach, exhibits and virtual talks can engage students and families.
Practical skills: Skills in CT imaging, specimen preservation and data analysis are transferable to biomedical imaging, manufacturing quality control and environmental monitoring — local workforce strengths that could benefit from growth in marine science funding.
Reporting and sources
This report draws on the original Tulane news release, scientific records and summary commentary. Key sources include:
- Tulane University press release: Researchers identify new species of pocket shark
- Wikipedia entry for Mollisquama mississippiensis
- Summary piece at The Archaeologist
- Sophie Maycock’s summary on the discovery
For readers seeking technical detail, the Tulane University press release outlines the collection, imaging and taxonomic steps leading to the formal identification of the American pocket shark.
