The red flabellina (Flabellina trophina) is known for having a long mouth that protrudes forward and is often raised up above the substrate. The reddish cores in the dorsal gills (cerata) are an identifying feature, and also that the rhinophores have rings encircling them. The red flabellina can grow to 4.7 inches (12 cm) long, with a range that includes the Sea of Japan, and southern Alaska to central Oregon.
