Caulerpa

Scientific name: Caulerpa taxifolia, Caulerpa prolifera, Caulerpa racemosa Taxonomic type: Siphoned chlorophyte Water: Marina Color: Deep green Texture: Soft, creeping stolons with upright fronds that vary in shape depending on the species

Appearance: A creeping algal plant with stolons that attach to rocks and vertical fronds. C. racemosa has grape-shaped fronds. C. taxifolia has feathery fronds. C. prolifera has lanceolate fronds.

Is it dangerous?:

C. taxifolia is an invasive species in the Mediterranean, and its sale is illegal in many countries.
In the aquarium, it can be useful in the refuge tank for removing nutrients.
Corals can overgrow the display.
Plants can "spore" (mass sexual reproduction) by releasing gametes that completely poison the aquarium—this occurs when they are under stress.

Proper use: Keep in a shelter as a nutrient source; prune regularly (never let it "spore"); never leave it on display without supervision.

How to remove it:

Instructions: Pull up carefully; do not leave any pieces behind (it will regrow from any fragment).
Herbivores: Tang, Foxface, Rabbitfish.
Darkness: 3–5 days of darkness.