When I tell people that I work with abalone I get one of two reactions: “Oh cool…” followed by a slow head nod (a.k.a. they have no idea what abalone are) or “Oh I ate that once!”. So I thought it would be a good idea to do an informative blog post on abalone for y’all’s (is that a word?) education. If you are like most people, you have seen abalone in one of two ways:
Hopefully, after you read this post you will have a new found appreciation for abalone.
What are abalone?
Abalone are marine gastropod molluscs, which means they are marine snails. There are 7 species on the West Coast, and about 60-100 species recognized globally. I will focus on the 7 species found on the West Coast: pinto abalone (also known as Northern abalone), black, white, pink, red, green, and threaded.
My work in the Friedman lab focuses on pinto abalone restoration and development of new tagging methods for abalone (see my manuscript on tagging here). The Friedman lab also has black and red abalone. If you would like to learn more about the Pinto Abalone restoration project in Washington, go here or watch the video here. For current information (November 2013) on Pinto abalone status in Washington State, see my post here.
What does an abalone look like?
Abalone are single shelled snails with a large muscular foot to hold them to rocks. The basic external anatomy of an abalone includes a shell with respiratory pores and apex, foot muscle, head with cephalic tentacles and eyes, and epipodial tissue surrounding the shell. Respiratory pores are used for reproduction, waste elimination, and breathing.
The most important external structures on abalone to recognize for species identification are the number of open respiratory pores, shell shape and color, size, and epipodial tissue and tentacle color. Abalone have a relatively flat shell with a spiral shaped top, called the apex. When viewing abalone from above, with their back end facing you (the apex), the respiratory pores run along the left side. Often times the mantle tissue covers the inside of the pores, giving them color inside. Depending on the species, they can be raised or even with their shell.
Abalone have two larger tentacles that come off their head, called the cephalic tentacles. They also have many smaller tentacles called the epipodial tentacles all around their shell. The cephalic tentacles are much thicker and often longer than the smaller epipodial tentacles. Different abalone species have varying coloration of their tentacles, so this can be a good external way to identify the species. Along the edge of their shell, depending on the animal, a ring of tissue can be seen, called the epipodial tissue where the epipodial tentacles attach to the body. Depending on the species this tissue can be a variety of colors and textures. Abalone shells can also be a variety of shapes and textures. Some are bumpy and have ridges, like pinto abalone, others are very smooth, like the black abalone.
What does a day in the life of an abalone look like?
Abalone eat diatoms and microalgae as juveniles and macroalgae as young adults and adults, like bull kelp, turkish towel, dulse, and laminaria. They use their specialized zipper like “tongue” to scrape algae. When they aren’t eating, they spend most of their time hunkered down in “home scars” on or under rocks to avoid being eaten. Their most common predators are sea otters and the sun star Pycnopodia (Pycno). See a video of a juvenile abalone escaping a pycno here. Abalone are either male or female, and when they reproduce they broadcast spawn like many invertebrates. They release their gametes through their respiratory pores.
Why do I think abalone are cool?
One of my favorite things about my job is watching abalone behaviors. While it may seem boring watching a snail, these guys are really cool! They can be very active, especially when eating or escaping predators. When they sense a predator, they sometimes show a behavior called “torsion”, where they twist their shell around, attempting to remove whatever predator is touching their shell. Then, often times, they get up and move! They move a lot faster than you would think (see video above). They also show fun behaviors during feeding. They will reach out parts of their foot muscle to grasp at pieces of algae. I also find their eyes very interesting- I get a sense of their personality. That may sound silly since abalone don’t have brains, they have a cerebral ganglion and are often considered “primitive”. I think their behaviors are what sets them apart from other marine snails and they are a very unique species.
Why are abalone important?
Other than consumption and jewelry production, abalone are important culturally and ecologically. Culturally they are important because many Native tribes on the West Coast have harvested abalone for their meat and shells. Ecologically, they maintain habitat. Urchins and abalone are believed to preform similar ecological functions by controlling algal density. It is hard to justify why it is important to prevent the extinction of certain animals, as it is difficult to assign “worth” to a species, other than economically or culturally. However, I do know that I would like future generations to be able to enjoy this unique animal, and we can only do that if this species is able to rebound globally.
-Abalone have gills! They have two gills internally, close to their respiratory pores
-It is correct to say either “abalone” or “abalones” when talking about multiple abalone
And an answer to a common question: No, I have not eaten abalone. The recreational harvest of pinto abalone has been illegal in Washington since 1994. It is also illegal to harvest abalone in California with SCUBA, and free divers are limited in the number of abalone they can take. Since 1969, abalone populations have declined globally more than 50% (FAO, Fisheries and Aquaculture, 2008), with many species now recognized as threatened, endangered, or species of concern. I personally don’t eat abalone, just in case someone isn’t being truthful about the origin of the animal, as the sale of abalone on the black market is pretty common.
Please let me know if you have question or corrections! I will do my best to address them.