International
Mollusc of the
Year 2025

Voting for the International Mollusc of the Year 2025 takes place
from March 3 (10:00 CET) to March 31 (23:59 CET).

The results will be announced in an official press release on April 3.

You can vote once – so think carefully about which mollusc you want to support! Your vote will be checked against your e-mail address. Be sure to confirm your vote using the link sent to the email address you provided to ensure it is valid. The data we collect – including the email address – will be deleted after evaluation.

 

About the Project

Welcome to the fascinating world of molluscs! From snails and slugs to clams, octopus and more – these creatures are as diverse as this year’s five finalists. “International Mollusc of the Year” celebrates their remarkable characteristics and inspires fascination for molluscs worldwide. Your vote decides the top mollusc, and Senckenberg will sequence the complete genome of the winner.

     

The Deep-sea Octopus Muusoctopus is the “Mollusk of the Year 2025”

The deep-sea octopus Muusoctopus received over 1,300 votes, edging out the “blue dragon” sea slug (Glaucus atlanticus), the Atlantic carrier snail (Xenophora conchyliophora), the Hawaiian black-footed limpet (Cellana exarata), and the ocean quahog (Arctica islandica). More than 4,000 mollusk fans voted in the poll.
The genus Muusoctopus includes octopuses that live in the icy depths of the oceans. One of the ways they differ from their shallow-water relatives is their lack of an ink bladder – an adaptation to the darkness of the deep sea where few predators lurk. It was only recently discovered that a Muusoctopus species, the “Dorado Octopus,” forms huge colonies at a depth of around 3,000 meters off the coast of Costa Rica. The females of this species appear to incubate their eggs exclusively in the warm waters of hydrothermal vents – an extraordinary behavior that is revolutionizing our understanding of deep-sea ecology, reproduction, and evolution.

Read the press release

Finalists of the International Mollusc of the Year 2025

Explore the finalists’ profiles, discover their fascinating features, and uncover what secrets their genome could reveal.
Once you’ve picked your favourite, vote by clicking the white button and confirming your email address. Thank you for joining us to love these remarkable molluscs! Share the campaign on social media and spread the word!

Arctica islandica

The Timekeeper of the Sea

The Ocean Quahog, Arctica islandica, acts as a living archive of Earth's history, recording centuries of oceanic and climatic changes in the rings of its shell—some specimens are over 500 years old.

Xenophora conchyliophora

The Seafloor Decorator

The Atlantic Carrier Shell, Xenophora conchyliophora, cements objects like seashells, coral fragments, and even glass pieces onto its shell, creating an intricate mosaic that serves as both camouflage and sturdy protection

Cellana exarata

The Intertidal Survivor

The Hawaiian Blackfoot Limpet Cellana exarata, a culturally cherished symbol of the Pacific Islands, is a master of survival, enduring constant waves and scorching sun on exposed rocks.

Muusoctopus

The Dorado Octopus

Octopuses of the genus Muusoctopus live in the icy darkness of the deep sea. According to recent findings, one species incubates its offspring near warm hydrothermal vents.

Glaucus atlanticus

The Ocean’s Blue Dragon

The Blue Dragon Glaucus atlanticus is a tiny, predatory sea slug with a spectacular appearance and a highly sophisticated defense strategy, using 'stolen' stinging cells from venomous siphonophores.

Let's explore molluscs!

The phylum Mollusca originated over 500 million years ago. Many species are still waiting to be discovered today. Genomic analyses can answer many open questions about evolution, ecology, and behaviour – but so far, only a few mollusc species have had their genomes sequenced. This is where the “International Mollusc of the Year” comes in.

Previous winners

The International Mollusc of the Year 2024Phuphania crossei, the living glow stick

The snail from Thailand won more than half the votes, beating two other snail species, a mussel, and a small squid. Phuphania crossei is an air-breathing land snail found only in the tropical forests of Thailand. It takes its name from the Phu Phan mountains in the north-east of the country. Its special feature is that it constantly produces its own bioluminescent light, emitting a greenish glow like a living glow stick. At first glance, Phuphania crossei is a normal looking snail, with a yellowish-brown body and a dark grey head with eyes on stalks. Its shell is brownish with distinct ribs. However, even in daylight and without stimulation, its greenish glow is visible to the human eye. The glow is produced by light cells on the foot and the mantle. The snail can switch off this glow temporarily.

Press release

The International Mollusc of the Year 2023 – Concholepas concholepas, the Chilean Abalone

Concholepas concholepas belongs to the family of Murex snails, which are mostly much more spectacular seashells; Concholepas is found in the south-eastern Pacific and adult specimens can reach a shell length of about 15 centimetres. As a carnivore, it plays the role of a keystone species that controls the occurrence of other species. Known in its native country as “Loco” (a loanword of the Mapuche people in Chile), the snail with the large foot and tough shell has great cultural, social, economic, evolutionary, and ecological importance there. But its stocks are endangered due to severe overfishing, as the Chilean Abalone is traded worldwide as a delicacy.
Press release

The International Mollusc of the Year 2022Polymita picta, The Cuban painted snail 

The two to three centimetre Cuban painted snail is known for the colourful variations of its shell. It also has an enigmatic “love arrow” – a chalk arrow used to stab mating partners in order to transfer sex hormones. The snails are male and female at the same time, without being able to fertilise themselves, and reproduce during the rainy season. They live for about one to two years. The Cuban painted snail is only found along a narrow coastal strip in eastern Cuba. There, however, it inhabits a wide range of habitats, from extremely dry sites to rainforests. It feeds on moss and lichens on tree bark. In this way, it helps to keep trees healthy and thus supports local agriculture. Due to habitat loss and poaching, it is considered endangered.
Press release

The International Mollusc of the Year 2021Argonauta argo, The Greater Argonaut

Argonauta argo has been called the “most romantic” mollusc, evoking long sea voyages and a spirit of adventure. The Greater Argonaut is a type of pelagic octopus, which lives close to the surface, with only a passing resemblance to its more familiar octopus cousins that live on the seafloor. The female Argonaut has specially adapted arms that look like oars and secrete a paper-thin porcelain shell. The unique shell serves her as a boat and also a protective case for her eggs. The male of the species is very different, and much smaller than the female. Argonauts are also voracious predators, they bite their prey and inject a poison produced in their salivary gland.
Press release

Nominate your favorite Mollusc for the International Mollusc of the Year 2026

Nominations for the International Mollusc of the Year competition are open all year round! In January, Senckenberg and Unitas Malacologica will select 5 top molluscs from the nominations, and the final winner will be determined by a public vote in early 2026. The nomination form is available at  https://sgn.one/475

 

Organizers and partners

The Senckenberg Society for Nature Research is an institution of the Leibniz Association and has been researching the “System Earth” worldwide for over 200 years – in the past, the present and with forecasts for the future. We conduct integrative “geobiodiversity research” with the aim of understanding nature with its infinite diversity in order to preserve it as the basis of life for future generations and to use it sustainably. In addition, Senckenberg communicates research results in a variety of ways, especially in the three nature museums in Frankfurt, Görlitz and Dresden. The Senckenberg Nature Museums are places of learning and wonder, and they serve as open platforms for democratic dialogue – inclusive, participatory and international.
More information at www.senckenberg.de
 

Unitas Malacologica is the society for worldwide malacologists and malacology. Its aim is to further the study of Mollusca by individuals, societies and institutions worldwide. The purpose is realized in particular by the organization of international congresses, usually the World Congress of Malacology in three-year intervals, and awarding grants and prizes to young researchers in the field of malacology. More information:  http://www.unitasmalacologica.org/

The Leibniz Association connects 96 independent research institutions that range in focus from natural, engineering and environmental sciences to economics, spatial and social sciences and the humanities. Leibniz Institutes address issues of social, economic and ecological relevance. They conduct knowledge-driven and applied basic research, maintain scientific infrastructure and provide research-based services. The Leibniz Association identifies focus areas for knowledge transfer to policy-makers, academia, business and the public. Leibniz institutions collaborate intensively with universities – in the form of “Leibniz ScienceCampi” (thematic partnerships between university and non-university research institutes), for example – as well as with industry and other partners at home and abroad. They are subject to an independent evaluation procedure that is unparalleled in its transparency. Due to the importance of the institutions for the country as a whole, they are funded jointly by the Federation and the Länder, employing some 20,500 individuals, including 11,500 researchers. The entire budget of all the institutes is approximately 2 billion Euros.

www.leibniz-gemeinschaft.de

Sequencing partner:
Bioscientia Institut für medizinische Diagnostik GmbH