Trapania lineata

Trapania lineata is a small nudibranch that reaches a length of up to 15 mm. Its body is translucent white, adorned with a pattern of opaque white lines that extend into the lateral papillae. The tips of its oral tentacles, rhinophores, gills, and lateral processes are marked with yellow-orange pigment, and a narrow white stripe runs along the tail, culminating in an orange tip. This unique coloration aids in distinguishing it from other nudibranchs within the Goniodorididae family. This species is found throughout the Mediterranean Sea, with recorded locations ranging from Antalya, Turkey, to Spain. It typically inhabits demersal environments and is usually observed at depths less than 40 meters, with the majority of sightings occurring at depths shallower than 30 meters. Trapania lineata primarily feeds on Entoprocta, which commonly grow on sponges, making these habitats essential for its diet. Trapania lineata reproduces as a simultaneous hermaphrodite, engaging in a mating behavior where individuals will attempt to penetrate each other's body wall to establish dominance. The successful individual then fertilizes the other. Eggs are deposited on a suitable substrate, where they hatch into a planktonic larval stage before developing into adults. Encounters with this species during dives can be captivating, as divers may observe its slow movements while it feeds on sponges. The conservation status of Trapania lineata has not been assessed, and it has been recorded at various dive sites within its distribution range, indicating a presence across multiple locations.