Abalone Biology (download an abalone factsheet)

Abalone are marine snails (class: Gastropoda, phylum: mollusca), known worldwide for their beautiful, mother-of-pearl shell and their large muscular foot, a prized delicacy. Their genus, Haliotis, means "sea ear", a testament to their shape.

Where do abalone live?
More than 60 abalone species are found worldwide but pinto, or northern, abalone is the only one found in Washington State. Pintos historically ranged from California to Alaska, and are generally found between the surface and 35 ft (10 m) of water. They prefer nearshore, rocky habitats with large macroalgae and crustose coralline algae (a hard, thin layer of pink material seen on many rocks).

How do abalone eat?
Abalone use a file-like tongue, or radula, to scrape away at macroalgae, or kelp (Nereocystis or Macrocystis). When they are young, this radula is used to scrape diatoms, or microalgae, off of rocks.

How do abalone protect themselves?
The abalone’s strong muscular foot holds it firmly onto rocks while the shell acts as a protective shield against predators. They spend much of their lives hidden in crevices and under ledges and as they grow, their well-camoflauged shells become covered in algae, bryozoans or other hitchhiking invertebrates, making them especially cryptic.

What eats abalone?
Abalone’s natural predators include pycnopodia (a voracious sea star), sea otters and certain predatory fish, like cabezon. But their most substantial predators are humans.

How do abalone reproduce?
Abalone are broadcast spawners. Males and females release sperm and eggs into the water column and these gametes must find each other in order to fertilize successfully. This requires individuals to be close together and in sufficient numbers in order for populations to be sustainable.

How many abalone are there?
Because they hide so well, abalone are very difficult to count, but a special dive team from Washington Department of Fish and Wildlife spends several months each year counting abalone at several locations. These divers have discovered that surveyed populations in Washington have declined by nearly 80% since 1992. If abalone continue to decline at such rates, they will become extinct from Washington in just a few more years.

Did you know:
Abalone are hemophiliacs. This means that any disturbance to these animals that results in even the slightest laceration can prove fatal. Divers should be especially careful when they find an abalone. Abalone should not be removed from the rocks, even for casual observation or photography. The abalone won’t run away, so take your time and observe them as they are. Remember the golden rule: “An abalone is like a margarita – best when it is on the rocks and with salt”.