Edible seaweed in the context of "Red algae"

Seafood is any form of sea life regarded as food by humans, prominently including fish and shellfish. Shellfish include various species of molluscs (e.g., bivalve molluscs such as clams, oysters, and mussels, and cephalopods such as octopus and squid), crustaceans (e.g. shrimp, crabs, and lobster), and echinoderms (e.g. sea cucumbers and sea urchins). Historically, marine mammals such as cetaceans (whales and dolphins) as well as seals have been eaten as food, though that happens to a lesser extent in modern times. Edible sea plants such as some seaweeds and microalgae are widely eaten as sea vegetables around the world, especially in Asia.

Seafood is an important source of (animal) protein in many diets around the world, especially in coastal areas. Semi-vegetarians who consume seafood as the only source of meat are said to adhere to pescetarianism.

An edible item is any item that is safe for humans to eat. "Edible" is differentiated from "eatable" because it does not indicate how an item tastes, only whether it is fit to be eaten. Nonpoisonous items found in nature – such as some mushrooms, insects, seaweed, and so forth – are referred to as edible. Processed items that normally are not ingested but are specially manufactured to be so, like edible underwear or edible packaging, are also labeled as edible.

Codium is a genus of edible green macroalgae (or seaweed) under the order Bryopsidales. The genus name is derived from a Greek word that pertains to the soft texture of its thallus. One of the foremost experts on Codium taxonomy was Paul Claude Silva at the University of California, Berkeley. Silva was able to describe 36 species for the genus, and in honor of his work on Codium, the species C. silvae was named after him.

Carrageenans or carrageenins (/ˌkærəˈɡiːnɪns/ KAH-rə-GHEE-nihns; from Irish carraigín 'little rock') are a family of natural linear sulfated polysaccharides. They are extracted from red edible seaweeds. Carrageenans are widely used in the food industry, for their gelling, thickening, and stabilizing properties. Their main application is in dairy and meat products, due to their strong binding to food proteins. Carrageenans have emerged as a promising candidate in tissue engineering and regenerative medicine applications as they resemble animal glycosaminoglycans (GAGs). They are used for tissue engineering, wound coverage, and drug delivery.

Carrageenans contain 15–40% ester-sulfate content, which makes them anionic polysaccharides. They can be mainly categorized into three classes based on their sulfate content. Kappa-carrageenan has one sulfate group per disaccharide, iota-carrageenan has two, and lambda-carrageenan has three.