Scientists Describe Newly Discovered Mesophotic Red Alga from Papahānaumokuākea National Marine Sanctuary

December 18, 2025

A team of NOAA, University of Hawaiʻi, and partner scientists have formally described a new species of red alga found within Papahānaumokuākea National Marine Sanctuary. The species, Gloiocladia laukuamoo, was published on Oct. 17 in the peer-reviewed journal Cryptogamie, Algologie, and adds to our growing understanding of life in Hawai‘i's mesophotic coral ecosystems.

a clump of red algae on the seafloor — In situ specimen of *Gloiocladia laukuamoo* in Papahānaumokuākea National Marine Sanctuary prior to collection. Photo: NOAA

A Discovery from the Ocean's "Twilight Zone"

The new species was collected at depths of 182-281 feet—a zone often called the "twilight" or mesophotic region, where sunlight is faint but still supports specialized marine life. NOAA divers Jason Leonard, Daniel Wagner, Brian Hauk, and Randy Kosaki gathered the specimens during NOAA research expeditions in 2013, 2014, 2015, and 2019.

To reach these depths safely, the team used closed-circuit mixed-gas rebreathers—advanced dive equipment that recycles breathing gas and allows divers to explore deeper and longer than traditional scuba gear.

Scientists identified one specimen as the primary reference sample for the species (known in taxonomy as a holotype) and additional supporting samples (known as paratypes). Together, these serve as the official scientific examples used to describe Gloiocladia laukuamoo.

A Name Rooted in Hawaiian Language and Place

The species epithet, laukuamo‘o, reflects several Hawaiian words:

lau - a leaf or blade; also conveys multiplicity

kua - back, or the shape of a human spine

mo‘o - the mourning gecko (Lepidodactylus lugubris), known for its sawtooth-shaped dorsal pattern

Together, these meanings reference the alga's intertwined, sawtooth-like body form and its biogeographical home along the “geological backbone” of the Hawaiian Archipelago—the Northwestern Hawaiian Islands, where Papahānaumokuākea National Marine Sanctuary is located.

The name was developed in collaboration with the Nomenclature Subcommittee of the Papahānaumokuākea Native Hawaiian Cultural Working Group to ensure respectful and accurate use of Hawaiian language and cultural knowledge.

a sample of red algae with many branches that have distinct sawtooth-like edges. — Collected specimen of *Gloiocladia laukuamoo*, confirmed to be a new species of red algae from Papahānaumokuākea. Photo: NOAA

Why This Discovery Matters

Documenting new species helps NOAA better understand, monitor, and protect the biodiversity of America's national marine sanctuaries. Research efforts like this support NOAA's mission under Section 309 of the National Marine Sanctuaries Act, which calls for coordinated exploration of sanctuary resources and for making scientific findings publicly available.