Goniobranchus annulatus, formerly known as Chromodoris annulata prior to 2012, is a species of sea slug belonging to the family Chromodorididae. Known for its vibrant colors, this shell-less marine gastropod mollusc is classified as a dorid nudibranch.
Measuring up to 100mm in length, Goniobranchus annulatus displays a smooth, pale body adorned with numerous vivid yellow spots, although this characteristic may be absent in certain individuals. The species showcases a distinctive purple ring encircling its gills and another ring around its rhinophores. Additionally, the mantle typically features a purple border. The gills of this nudibranch take on a triangular shape in cross-section.
Initially described from Zanzibar, Goniobranchus annulatus is found in the 🌊 Red Sea and the 🌊 Indian Ocean, spanning from the East Coast of 🇿🇦 South Africa to 🇹🇭 Thailand. Notably, it is considered a Lessepsian migrant, indicating its recent invasion of the Mediterranean Sea, likely facilitated by the Suez Canal (🇪🇬 Egypt).
