Sea grapes

Caulerpa lentillifera

Also known as Green caviar, Umi budou, Sea grape caulerpa, Lato

SaltwaterMacroalgaeFragmentation

Sea grapes (Caulerpa lentillifera) — djpmapleferryman · CC BY 2.0

Care at a glance

Light: Medium light
CO2: No CO₂ needed
Temperature: 73–81°F; 23–27°C
Max height: 3.9 in; 10 cm

Growth rate: Fast
Placement: Background
Type: Macroalgae
pH: 8.0–8.4
Spread: 15.7 in (40 cm)
Nutrient uptake: Water column
Growth region: Submersed
Difficulty: Easy
Family: Caulerpaceae
Origin: A marine green macroalga of shallow tropical Indo-Pacific lagoons and reef flats, spreading over sand and rubble by creeping runners.

Overview

Sea grapes is a bright green marine alga made of round, grape-like beads strung along creeping runners. It is easy to grow and best kept in a sump or refugium, where it exports nutrients.

Did you know

Sea grapes is farmed as food across Southeast Asia and Japan. It is eaten fresh and sold as green caviar or umi budou.

Caring for sea grapes

Wedge sea grapes into rubble with gentle flow. Keep it out of the display, where it would crowd corals.

It wants moderate light and needs no added CO2. It feeds from the water, pulling nitrate and phosphate out as it spreads. Keep it at 73 to 81°F (23 to 27°C) with a pH of 8 to 8.4.

It grows fast and spreads quickly, so harvest it regularly. Pieces that break off keep growing, so pulling a clump apart is the easy way to start more. The dense beads also give copepods and other tiny creatures a place to shelter and breed.

Keep it well lit, because a stressed clump can suddenly go sexual, turn white and dissolve. That dumps its stored nutrients back into the tank. Many reefers run the refugium light on an opposite or continuous cycle to keep it stable.

Good to know

Like other Caulerpa, sea grapes is essentially one giant cell with many nuclei and no internal walls. Sap flows freely through its runners and beads. It grips the bottom with root-like holdfasts called rhizoids rather than true roots. Its species name is Caulerpa lentillifera, and it is also sold as lato.