The shell is usually brown and marked with many low, flat-topped ribs which run parallel to the five to seven open respiratory pores that are elevated above the shell’s surface. The inside of the shell is an iridescent blue and green. The epipodium is a “ruffle” of tissue along the side of the foot. The head and epipodial tentacles are olive green, but the epipodial fringes are a mottled cream and brown color, with knobby tubercles scattered on the surface and a frilly edge.
The green abalone's shell length can reach a maximum of 20 cm.
This species is found in shallow water on open/exposed coast from low intertidal to at least 30 feet (9 m) and perhaps as deep as 60 feet (18 m). Individuals are found in rock crevices, under rocks and other cryptic cavities. Like all abalones, Green abalone are herbivores. They feed mostly on drift algae and prefer fleshy red algae.
Green abalones are subject to a chronic, progressive and lethal disease: the Withering Syndrome or abalone wasting disease, leading to mass mortality.
Green abalone have separate sexes and broadcast spawn from early summer through early fall. Maturity is reached at 2.4 to 5 inches (61-128 mm) length or 5 to 7 years. Lifespan is up to 30 years or more.
Threats and conservation
Green abalone are threatened by overharvesting and the Withering abalone syndrome disease. California has a Abalone Recovery Management Plan to guide conservation efforts. They are a U.S. National Marine Fisheries Service Species of Concern. Species of Concern are those species about which the U.S. Government’s National Oceanic and Atmospheric Administration, National Marine Fisheries Service has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act (ESA).