Common name: Green Laver

General information

Ulva lactuca, commonly known as Sea Lettuce, is a bright green macroalgae widely found in shallow, marine waters. It is a member of the Ulvaceae family and is notable for its broad, leafy fronds which resemble lettuce leaves. This algae is not only important in the wild, serving as food for a variety of marine species, but it is also popular in the aquarium trade for its nutrient uptake abilities and ease of care.

Sea Lettuce is often used in refugiums where it can grow rapidly, absorbing excess nutrients like nitrates and phosphates from the water, thus helping to control algae blooms and improve overall water quality in the main display tank.

Care

In the home aquarium, Ulva lactuca is relatively undemanding. It requires moderate to high lighting to thrive and can benefit from water movement that simulates its natural tidal habitat. It can be easily attached to live rock or left free-floating. Regular pruning is recommended to maintain its growth and prevent it from overtaking the tank.

Symbiosis

While not involved in the classic symbiotic relationships seen with corals and fish, Sea Lettuce can play a role in the symbiotic health of the aquarium ecosystem. It provides a habitat for small microfauna, such as copepods and amphipods, which are beneficial for natural waste breakdown and can serve as a food source for fish and corals.

Habitat

Ulva lactuca is found in a range of marine environments from intertidal zones to depths where light can still penetrate. It is a cosmopolitan species, meaning it is widespread across the globe in suitable habitats. It often grows attached to rocks or other substrates but can also be found free-floating in nutrient-rich waters.