A 5-Star Year

April 1, 2022
By Tara Haelle

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Uokeaster ahi is one of five species of sea stars discovered in 2021. Credit: Ariadna Mecho © 2021

Every year scientists discover new species in the oceans, and 2021 was no different. In fact, researchers from the California Academy of Sciences alone found a dozen new sea slugs, seven new fish species, five new sea stars, four new sharks, two new sea pens, and a new pygmy pipehorse.

One of the new sea stars is the brilliant orange Uokeaster ahi, found in the waters of Rapa Nui, the native name for Easter Island. Ahi, referring to the sea star’s color, means “fire” in the language of Rapa Nui. The new echinoderm’s genus is also related to the culture of the island: Uokeaster is a combination of Easter and Uoke, the mythological sea god who sunk the island of Rapa Nui so that only its tallest mountains poked out of the water. This new sea star lives in the reefs just under the surface of the “original” Rapa Nui land.

But this fiery sea star wasn’t the only new one found in Rapa Nui’s waters. The scientist who discovered Uokeaster ahi also discovered the Hacelia raaraa and Linckia profunda sea stars. Also brilliant orange, the Linckia profunda sea star has slender, lanky arms compared to the stout thickness of Uokeaster ahi. And the Hacelia raaraa sea star falls somewhere in between, with arms that are thicker than Linckia profunda but more slender than Uokeaster ahi, and with a mottled orange and white coloring that probably helps it blend into the reefs.

In the nearby waters of New Caledonia, the researcher also discovered Ophidiaster colossus, a member of a group of very large sea stars, and Astroglypha pyramidata, only the second sea star of the genus Astroglypha and the first from the Pacific Ocean…rounding out a collection that makes 2021 a 5-star year.