Caulerpa

Caulerpa prolifera

Also known as Feather Caulerpa, Leafy Caulerpa, Caulerpa Algae

SaltwaterMacroalgaeCuttings

Invasive. Caulerpa prolifera is an aggressive invader outside its native range. It was first found on the US West Coast in Newport Bay, California in 2021, where even small fragments establish and displace native seagrass. Never release it or dump tank water into any waterway. Related Caulerpa taxifolia is outright prohibited in several regions.

Caulerpa (Caulerpa prolifera) — Krzysztof Ziarnek, Kenraiz · CC BY-SA 4.0

Care at a glance

Light: Medium light
CO2: No CO₂ needed
Growth rate: Fast
Placement: Background
Type: Macroalgae
Temperature: 73–81°F (23–27°C)
pH: 8.0–8.4
Max height: 5.9 in (15 cm)
Spread: 15.7 in (40 cm)
Nutrient uptake: Water column
Growth region: Submersed
Difficulty: Easy
Origin: Warm coastal waters worldwide, including the Mediterranean, Caribbean, and tropical Atlantic
Family: Caulerpaceae

Overview

Keepers use Caulerpa prolifera mainly as a refugium workhorse for nutrient export, where its fast growth strips nitrate and phosphate that would otherwise feed nuisance algae. It wants medium lighting and moderate flow, and it will not stop growing if fed, so trim and remove excess regularly to actually export the captured nutrients. The real risk is going sexual: a stressed patch or a sharp nutrient crash can trigger it to release its contents and crash overnight, clouding the water and dumping nutrients back in, so many people run the refugium light 24 hours a day and avoid letting nitrate and phosphate hit zero. It roots into sand, so it suits a display or refugium with a substrate rather than a bare glass sump.

In the wild

A green macroalga of shallow tropical and subtropical seas, rooting into sand and mud flats and seagrass beds with a creeping horizontal stolon that sends up flat, blade-like fronds. It thrives across the Mediterranean, Caribbean, and warm Atlantic where nutrient-rich, brightly lit shallows let it form dense low meadows.

Good to know

Caulerpa prolifera is coenocytic: the entire plant is effectively one giant multinucleate cell with no internal cross-walls, so cytoplasm streams freely through the stolon, upright fronds, and rhizoids. It anchors with rhizoids rather than true roots and feeds almost entirely from the water column, making it a strong nitrate and phosphate exporter. Like other Caulerpa it can undergo holocarpic sexual reproduction, converting nearly its whole body into gametes at once and then dying back.

Did you know

Because Caulerpa prolifera is one single cell, you can slice a frond off and it seals the wound and regrows, which is exactly why a stray fragment can seed a whole invasion in the wild.