Purple Sea Slug

Chromodoris sp.

Origin	Indo-Pacific reefs
Maximum Length	1.5–2 inches
Minimum Tank Size	30 gallons (established)
Reef Compatibility	Reef safe, but specialized — see cautions

Behavior

Chromodoris sea slugs are among the most beautiful nudibranchs in the ocean, displaying vivid purple, blue, and white coloration with contrasting margins. They glide slowly across live rock grazing on their specific prey. Their bright colors are aposematic — a warning to predators that they are distasteful or toxic, having sequestered chemical defenses from the sponges they eat. They are peaceful and harmless to corals and other tank inhabitants.

Diet & Feeding

Specialist feeder. Chromodoris nudibranchs eat specific species of sponges and little else, which makes them difficult to sustain long-term in captivity. There is no practical prepared substitute; they slowly starve once their preferred sponge is exhausted. Best suited to experienced keepers with mature, sponge-rich systems.

Cautions

Difficult to keep long-term due to their highly specialized sponge diet — most starve within weeks to months in typical aquariums. When they die they can release toxins that may harm tank mates. Not reef-unsafe in the usual sense, but a challenging specimen. Never expose to powerheads without guards — soft-bodied and easily injured.