Two new luminous springtail species discovered on Miyako Island

A research team led by Curator Atsuko Ohira at Tamarokuto Science Center (Yokohama National University research supporter), and Professor Taizo Nakamori of Yokohama National University discovered four luminous species among springtails collected from Miyako Island, Iriomote Island, and Yonaguni Island in Okinawa Prefecture, and revealed that two of these are new species. This marks the world's first report of bioluminescence in the genus Crossodonthina Yosii. The findings were published in Zootaxa.

Springtails (collembola) are terrestrial arthropods measuring several millimeters in length, with approximately 9,000 known species worldwide. Currently, only about a dozen luminous species are known. Due to their small size and taxonomic complexity, the existence of luminous species may have been overlooked. Specialized methods are required for confirming luminescence and species identification, suggesting that many unknown species likely remain hidden.

In 2023, the research group reported that four known Japanese species possess luminescence. Such knowledge has accumulated, and this time four species were newly identified as luminous species (two of which are new species found on Miyako Island). One of the new luminous springtail species belongs to the genus Lobella, which was previously known to include luminous species: Akahoshi-akaibotobi mushi (scientific name: Lobella lucifera). The name "lucifera" derives from the Latin adjective "lucifer," meaning "light-bringing." It was named in reference to this species' luminescent ability. The other belongs to the genus Crossodonthina, previously unknown to be luminous: Shishigami-akafusaibotobi mushi (scientific name: Crossodonthina leodeus). "Leodeus" means "lion god." This species was named because it was discovered at a location with a large shisa slide, and shisa are the traditional guardian lion-dog spirits of Okinawa, hence the name "Shishigami" (lion god).

Additionally, fuchimi-akafusaibotobi mushi and kubiwa-akafusaibotobi mushi have red body coloration with protrusions (tubercles) on their body surface. When stimulated, these tubercles emit green light. Morphological observations confirmed that each represents a distinct species, and DNA analysis supported these taxonomic results.

With this discovery, the total number of known luminous springtails in Japan reaches eight species, making Japan the country with the most confirmed diversity of luminous springtails worldwide. While the mechanisms of luminescence and its ecological roles remain unclear, this research reveals undiscovered diversity among terrestrial luminous arthropods and provides new perspectives for biodiversity research.

The research team's published paper suggests that additional luminous species may exist within the genera Lobella and Crossodonthina, and that new luminous species may be found in other genera as well. Further investigations are expected to lead to the discovery of unknown luminous springtails.

Journal Information
Publication: Zootaxa
Title: Two new luminous species of Neanuridae (Collembola) and the discovery of bioluminescence in the genus Crossodonthina Yosii
DOI: 10.11646/zootaxa.5659.3.4