The 'leaf sheep' sea slug, scientifically known as Costasiella kuroshimae, has officially won the 2026 Invertebrate of the Year title. The competition, which aims to raise awareness for the vast diversity of spineless animals that constitute the majority of Earth's animal life, saw hundreds of thousands of participants cast their votes in a global ballot.

Broadcaster and environmental campaigner Chris Packham announced the results, praising the slug for its unique biological traits. The creature, which is roughly the size of a grain of rice, is noted for its neon green appearance and its ability to perform photosynthesis. According to Packham, the slug is capable of harvesting photosynthetic material from the algae it consumes, a process that allows it to supplement its energy intake through sunlight.

The competition has grown in popularity, serving as a platform to draw public attention to invertebrates that are often overlooked in conservation discussions. By focusing on the 'leaf sheep,' organizers hope to foster a greater appreciation for the complex roles these small organisms play in marine ecosystems. While the event is framed as a lighthearted contest, it emphasizes the scientific curiosity surrounding creatures that are frequently ignored due to their small stature and lack of a backbone.