Georgette Douwma / Funnelweed (Padina gymnospora) and Green Algae (Halimeda sp.). West Papua, Indonesia. Indo-West Pacific.

Georgette Douwma / Sea grapes (Caulerpa recemosa). Caulerpa. North Sulawesi, Indonesia.

Georgette Douwma / Green algae (Halimeda opuntia). North Sulawesi, Indonesia.

Georgette Douwma / Sea grapes (Caulerpa recemosa). Caulerpa. North Sulawesi, Indonesia.

David Fleetham / Red encrusting sponge (Clathria sp) on calcium carbonate-producing Seaweed / Green algae (Halimeda kanaloana). Hawaii.

Linda Pitkin / Spotted Seahorse (Hippocampus taeniopterus), resting in patch of green algae (Halimeda) Lembeh Strait, North Sulawesi, Indonesia.

Sue Daly / Velvet horn (Codium tomentosum) on sea shore, Sark, British Channel Islands.

MYN / Carsten Krieger / Velvet Horn (Codium tomentosum) from tidepool, County Clare, Republic of Ireland, December. Meetyourneighbours.net project

MYN / Carsten Krieger / Velvet Horn (Codium tomentosum) from tidepool, County Clare, Republic of reland, December. Meetyourneighbours.net project

Franco Banfi / Crinoid (Antedon mediterranea) on Seaweed (Codium bursa) Stupiste In dive site, Vis Island, Croatia, Adriatic Sea, Mediterranean

David Hall / Mangrove ecosystem with algae (Halimeda), Sponges (Porifera), Solitary tunicates (Polycarpa sp.), Colonial ascidians (Atriolum sp.), a mound-like Hard coral colony (Faviidae), and feather-like Colonia...

Tom Vierus / A local woman harvesting Sea grapes (Caulerpa lentillifera), a commonly consumed local food, in about 2m depth at a rivermouth near Munda. New Georgia, Western Province, Solomon Islands. July, 2023.

Alex Mustard / Sap-sucking slug / Shaun the sheep slug (Costasiella kuroshimae) crawling across algae (Avrainvillea sp.) on the seabed, Bitung, North Sulawesi, Indonesia, Lembeh Strait.

Alex Mustard / Sap-sucking slug / Shaun the sheep slug (Costasiella kuroshimae) crawling across green algae (Avrainvillea sp.) on seabed, Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Fred Bavendam / Blue-ringed octopus (Hapalochlaena sp.) clinging on to branch of Halimeda seaweed (Halimeda sp.), Milne Bay, Papua New Guinea, Pacific Ocean.

Tony Wu / Male Crowned seahorse (Hippocampus coronatus) nestled amongst Holmes seaweed (Codium cylindrical), carrying a pouch full of developing juveniles that are almost ready to emerge, Japan, Pacific Ocean.

Sergio Hanquet / Green algae (Codium sp) Tenerife, Canary Islands.

Sergio Hanquet / Green algae (Caulerpa webbiana) Tenerife, Canary Islands.

Sergio Hanquet / Clingfish (Opeatogenys cadenati) camouflaged on seaweed, Tenerife, Canary Islands.

Sergio Hanquet / Grass crack anemone (Paranemonia cinerea) on seaweed (Caulerpa prolifera) Tenerife, Canary Islands.

Sergio Hanquet / Sea snail (Smaragdia viridis) on seaweed (Caulerpa prolifera) Tenerife, Canary Islands.

Sergio Hanquet / Sea snails (Smaragdia viridis) on seaweed (Caulerpa prolifera) Tenerife, Canary Islands.

Sergio Hanquet / Sea snail (Oxynoe olivacea) on seaweed (Caulerpa prolifera) Tenerife, Canary Islands.

Sergio Hanquet / Sea snail (Oxynoe benchijigua) on seaweed (Caulerpa prolifera) Tenerife, Canary Islands.

Georgette Douwma / Green algae (Halimeda sp). Derawan Islands, East Kalimantan, Indoneisa.