International Mollusc of the Year 2025

Vote for your favorite mollusc to win ultimate prize: a fully sequenced genome!


Which mollusc will win the race? Starting today, all fans of snails, octopuses, and the like can cast their vote at https://moty.senckenberg.science and decide which of the five species in the final deserves the title of “International Mollusc of the Year 2025.”

This is the fifth time that the Senckenberg Gesellschaft für Naturforschung and Unitas Malacologica, the global society for mollusc research, have launched this campaign. The objective is to increase awareness of this fascinating and species-rich group of animals and promote their protection. A special prize is in store for the winning species: Its genome will be fully decoded for the first time.

“By selecting the ‘Mollusk of the Year 2025,’ we want to celebrate the impressive diversity of molluscs, which represent the second-most diverse group of animals in the world. From tiny snails and bivalves to giant squid, they have conquered almost every habitat on earth, from the deep sea to tropical rainforests,” explains Dr. Carola Greve from the Senckenberg Research Institute and Natural History Museum Frankfurt. “This diversity of shapes, lifestyles, and adaptations is also reflected by our five exceptional candidates in this year’s competition.”

The nominees comprise the deep-sea octopus Muusoctopus, the Hawaiian black-footed limpet (Cellana exarata), the “blue dragon” sea slug (Glaucus atlanticus), the Atlantic carrier snail (Xenophora conchyliophora), and the ocean quahog (Arctica islandica). They were selected by a jury of researchers from Senckenberg and Unitas Malacologica from over 30 nominations submitted by the international scientific community.

From March 3rd to 31st, mollusc fans can learn more about the nominated species and vote for their favorite on the website https://moty.senckenberg.science.

“We are absolutely thrilled with the species that have been suggested for the competition from all over the world – choosing this year’s five finalists was once again not an easy task,” reports Prof. Dr. Julia Sigwart, Head of Malacology at the Senckenberg Research Institute and Natural History Museum Frankfurt. “All candidates are characterized by their own history and unique features.”

Octopuses of the genus Muusoctopus live in the icy darkness of the deep sea. According to the latest findings, one species hatches its offspring there next to warm hydrothermal vents. The Hawaiian black-footed limpet (Cellana exarata), a culturally valued symbol of the Pacific Islands, defies constant waves and scorching sun as a survival artist on exposed rocks. The blue dragon (Glaucus atlanticus) is a tiny predatory sea slug with a spectacular appearance and a highly sophisticated defense strategy using ‘hijacked’ cnidocytes of venomous siphonophores such as the Portuguese man o’ war. The Atlantic carrier snail (Xenophora conchyliophora) cements objects like clam shells, coral fragments, and even pieces of glass onto its shell to create an elaborate mosaic, providing both camouflage and robust protection. As a living archive of the earth’s history, the ocean quahog (Arctica islandica) stores centuries of oceanic and climatic changes in the rings of its shell – some specimens are over 500 years old.

“With the selection of the ‘International Mollusc of the Year,’ we want to highlight the diversity and exceptional nature of this group of animals and emphasize the importance of protecting and further studying them. Many species have yet to be discovered and scientifically described,” explains Sigwart. Greve adds, “Moreover, there is enormous genomic diversity among the molluscs. Yet, only relatively few genomes have been fully sequenced to date. In order to better understand these fascinating animals, we will fully decode the genome of the winning species at Senckenberg. We are already very excited to see which species will be awarded the title this year!” 

The “International Mollusk of the Year 2025” will be unveiled on April 3.

You can cast your vote on the following website, which also contains short portraits of the five finalist species: https://moty.senckenberg.science

Meet the Mollusc Contestants

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Marie-Galante Guadeloupe
The Atlantic carrier shell, Xenophora conchyliophora, is one of the ocean’s most creative molluscs. This gastropod collects and cements shells, coral fragments, and other debris onto its own shell, constructing an intricate mosaic that serves as both camouflage and a weight-balancing mechanism.
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Schmidt Ocean Institute, CC-by-SA 4
Muusoctopus is a genus of deep-sea octopuses that thrives in some of the ocean’s most extreme environments. This Muusoctopus species was discovered in a vast deep-sea octopus nursery near Costa Rica, where thousands of mothers brood their eggs in warm hydrothermal vent waters.
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Sophia Samus
The Hawaiian black-foot limpet, Cellana exarata (‘opihi makai‘auli), is a true icon of Pacific island shorelines. Enduring relentless waves and scorching sun, it clings to exposed rocks where few other creatures can survive. 
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Xavi Salvado
Glaucus atlanticus is a tiny but formidable predator, floating upside down on the ocean’s surface like a living jewel – but a dangerous one! This nudibranch preys on venomous siphonophores, including the Portuguese man o’ war, stealing their stinging cells and repurposing them as its own weapon.
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Fabian Wolf
The ocean quahog, Arctica islandica, is a living chronicle of Earth’s history. Some individuals have been found to be over 500 years old, making them one of the longest-lived non-colonial animals known to science.