Gary Bell/ Oceanwide / Sea Lettuce (Ulva australis) and other alga, Hopkins Island, South Australia, Australia

Solvin Zankl / Intertidal rocks covered in seaweeds, including, brown algae: at top Toothed wrack (Fucus serratus) and on the left Bifurcaria bifurcata. Red algae: middle and bottom right Pepper dulse (Osmundea pinn...

Solvin Zankl / Dried Sea lettuce algae (Ulva sp.), Roscoff, France, April.

Nick Upton / Gametophyte of Harpoon weed (Asparagopsis armata), an invasive red alga attached with barbed branchlets to Sea lettuce (Ulva lactuca) in a rockpool low on the shore, near Falmouth, Cornwall, UK, Augus...

Nick Upton / Broad-clawed porcelain crab (Porcellana platycheles) hiding behind Gutweed (Ulva / Enteromorpha intestinalis) in a rockpool alongide a Flat / Purple top shell (Gibbula umbilicalis) and a Limpet (Patel...

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) feeding on Sea Lettuce (Ulva sp) at low tide, Galapagos Islands, Ecuador

Robert Thompson / Shore at low tide with seaweed {Ascophyllum sp} and {Ulva sp}, barnacles and Limpets {Patella vulgata} Ballyhenry Point, Strangford Lough, County Down, August 2007

Robert Thompson / Shore at low tide with seaweeds, Wrack {Ascophyllum sp} and Sea lettuce {Ulva sp}, Ballyhenry Point, Strangford Lough, County Down, August 2007

Robert Thompson / Knotted wrack {Ascophyllum nodosum var mackii} and sea lettuce {Ulva sp} exposed at low tide, Ballyhenry Point, Strangford Lough, County Down, Northern Ireland, UK, August

Sebastian Kennerknecht / California Mussel (Mytilus californianus) clusters, Barnacles (Balanus sp), Black Turban Snails (Tegula funebralis), Rockweed (Fucus sp), and Sea Lettuce (Ulva sp) in high tide zone, Santa Cruz, Monte...

Doug Perrine / Flagfin cardinalfish {Apogon hoeveni} in bed of Sea lettuce {Ulva sp} Secret Bay, Bali, Indonesia

Scott Leslie / Sea Lettuce (Ulva lactuca) and small snails, Nova Scotia, Canada