Common name: slender roboastra

General information

Roboastra gracilis, commonly known as the Graceful Roboastra or Blue Velvet Nudibranch, is a striking marine invertebrate known for its vibrant blue coloration and graceful movement. This species belongs to the order Nudibranchia, which comprises soft-bodied, marine gastropod mollusks known for their extraordinary colors and forms. Nudibranchs are often referred to as sea slugs, but they are quite distinct from the terrestrial slugs most people are familiar with.

Care

The Graceful Roboastra is a specialized predator, feeding exclusively on other nudibranchs, particularly those of the genus Tambja. This dietary requirement makes them challenging to keep in captivity, as their food sources are not easily cultured. They require a well-established reef tank with a diverse population of potential prey. Water quality must be maintained at high standards, with stable parameters to ensure their health.

Reproduction

Like many nudibranchs, Roboastra gracilis is a hermaphrodite, possessing both male and female reproductive organs. They can engage in reciprocal mating, where both individuals exchange sperm to fertilize their eggs. The eggs are laid in gelatinous spirals or ribbons, which are often attached to the substrate or tank glass.

Habitat

Roboastra gracilis is typically found in the Indo-Pacific region, from the Red Sea to South Africa and east to the central Pacific. They inhabit coral reefs and rocky substrates, often seen crawling over the surface in search of prey. In the wild, they can be found at various depths, usually not exceeding 30 meters.