Common name: Great Phyllodesmium

General information

Phyllodesmium magnum is a species of aeolid nudibranch, a marine gastropod mollusk in the family Facelinidae. This striking sea slug is known for its beautiful and intricate cerata that resemble the branches of soft corals, which is not a coincidence as it often feeds on and associates with various soft corals. It is a fascinating example of mimicry in the marine environment, allowing it to blend in with its surroundings and avoid predation.

Care

Phyllodesmium magnum requires a specialized aquarium setup that replicates its natural habitat. They are best suited for advanced hobbyists due to their specific dietary needs, feeding exclusively on certain types of soft corals. Stable water conditions and excellent water quality are crucial for their health. It is important to research the specific soft coral species that your Phyllodesmium magnum feeds on before introducing it to your tank.

Reproduction

Like many nudibranchs, Phyllodesmium magnum 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 and are often attached to the substrate or aquarium glass.

Symbiosis

Phyllodesmium magnum has a unique relationship with the soft corals it feeds on. While it does consume the coral, it also incorporates the coral's zooxanthellae (symbiotic algae) into its own tissues, a process known as kleptoplasty. This allows the nudibranch to benefit from photosynthesis, supplementing its diet with the sugars produced.

Habitat

This nudibranch is found in the tropical Indo-Pacific region, often associated with coral reefs where its preferred soft coral prey resides. They are typically found at depths where light is sufficient for the zooxanthellae to perform photosynthesis, which is vital for the nudibranch's kleptoplastic abilities.