- The red abalone’s shell length can reach a maximum of 12 inches
- The shell is large, thick, and dome-shaped. It is usually a brick red color externally, typically with algae growing on it
- Typically the shell has three or four raised oval holes (called respiratory pores), that are used for breathing, excreting waste, and reproduction
- The shape of the shell is determined by the crevice or crack the abalone grew up in
- The shell interior is famously iridescent
- The body of the animal (the foot and the tentacles) is black, and the underside is yellowish
- Sunset Bay, Oregon to Baja California, Mexico.
- Live in rocky areas with kelp
- Found at subtidal depths to about 180 feet
- Usually reach maturity at 5 inches, females may reach maturity as small as 1.5 inches and males as small as 3.3 inches
- Reproduce by broadcast spawning, where release sperm and eggs into the water
- A young female just releases a few thousand eggs, a large adult can release up to 6 million eggs
- In Northern California spawning is from April to July, in Southern California it is year-round
- When one abalone starts to spawn, it usually triggers others to start in the area
- Adults feed on the kelp species that grow in their home range, including giant kelp, feather boa kelp, and bull kelp
- Juveniles eat coralline algae, bacteria, and diatoms
- Sea otters and humans
- Humans have been harvesting red abalone for approximately 12,000 years
- It is the largest species of abalone in the world.
- It is the only species of abalone still legally harvested in California, and only by recreational divers and rock pickers, and only north of San Francisco Bay.
- Their population has mainly declined due to overfishing and withering syndrome.
- Abalone were eaten by native people along California’s coasts for thousands of years, and abalones shells are often found in large piles called middens at their settlement sites.
Sources: UC Santa Cruz; Aquarium of the Pacific; Evolution, distribution and systematics of Haliotidae, p. 3–18; World Register of Marine Species
Photo: Dave Rudie
NOAA’s Southwest Fisheries Science Center here in La Jolla is researching abalone and how to help them recover.