Blue Dragon

Pteraeolidia semperi

Pteraeolidia semperi - Blue Dragon
image_search Terms and anatomy

Size: 15 cm

Distribution: Gulf St. Vincent and Kangaroo Island

Habitat: Rocky reef and rubble

Depth: Subtidal to 10+ metres

This striking nudibranch is extremely elongated, with long purple-banded oral tentacles and purple-tipped rhinophores. Often a purple to blue colour, this species can also take on a greenish colouration, its colour partly influenced by the photosynthetic cells (zooxanthellae) that it incorporates into its cerata. The cerata themselves can be curled and flattened, and in this position, the animal resembles a traditional Chinese dragon, which inspires its common name. Although there is some variation in colour and appearance, it is unlikely to be mistaken for other species, even related aeolids, although the strongly banded oral tentacles and extremely long body are characteristic. As with other aeolids, it has stinging cells in its cerata, but unlike its relatives, it is capable of delivering a painful sting that can be felt by humans, and as such should not be handled. Some sources, including the Atlas of Living Australia, still consider this species to be synonymous with P. ianthina, found in NSW.