Notodoris serenae

Notodoris serenae is a type of sea slug that can reach lengths exceeding 10 cm. Its body is mainly grey and is adorned with raised black tubercles and prominent black ridges on its head and the areas in front of its gills. This nudibranch features large extra-brachial appendages that provide protection to its green gills, which may have yellow edges. The rhinophores and the underside of the foot are yellow, creating a contrast against its grey exterior. This species is distributed across the Indo-west Pacific region, with sightings reported in areas such as Papua New Guinea, the Philippines, Indonesia, Malaysia, Palau, Pohnpei, the Solomon Islands, and Okinawa. Notodoris serenae typically resides in shallow waters, with all recorded occurrences found at depths less than 40 meters, and the majority under 30 meters. Notodoris serenae primarily consumes calcareous sponges from the family Leucettidae, including Leucetta chagosensis as one of its known food sources. As a simultaneous hermaphrodite, this nudibranch exhibits a unique mating behavior where individuals attempt to penetrate each other's body wall, determining dominance in the mating process. Eggs are laid on a substrate, where they develop into a planktonic larval stage before transitioning into adults. Encounters with Notodoris serenae during dives can be interesting due to its unique coloration and physical features. The species has not been assessed for conservation status, indicating that there is currently no specific information available regarding its population trends or threats.