4 facts about abalone that doesn’t involve eating it

There’s more to the abalone than a luxury seafood that’s served during special occasions. Found in the cold waters off New Zealand, Australia, Japan, the west coast of the United States, and South Africa, this marine creature has a shell that has inspired science and is clever at escaping predators. Find out more about the abalone before you take a bite.

A familiar sight: Cooked abalone.
A familiar sight: Cooked abalone.

 

Scientific name: Haliotis

Animal type: Sea snail

Diet: Herbivore, grazing mainly on macroalgae.

Size: from 2cm to 20cm to 30cm depending on the species

Abalone are marine snails

The abalone shell and the abalone foot muscle.
The abalone shell and the abalone foot muscle.

Credit

We usually see shucked abalone served on the table. In its original form though, the abalone resembles a marine snail.

Unlike clams that have two shells, the abalone has a single shell on one side and its foot muscle on the other side. What is served on the dining table is the abalone’s foot muscle.

The abalone crawls with its foot muscle which has a strong suction power (equal to 4,000 times its body weight). Abalone hunters have to use special tools to remove abalone from the rocks.

Abalone shell is useful

The abalone isn’t just for eating. Its shell is used for decoration and is an inspiration in science. The inside of the abalone shell is a layer of mother-of-pearl which is used as decorative items for jewellery, buttons, buckles and inlay.

Mother of pearl in the inner red abalone shell
Mother of pearl in the inner red abalone shell

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Abalone shells are unusually strong. Scientists discovered that abalone shell is made up of microscopic tiles stacked like bricks that are held together by a clingy protein substance. The tiles slide over each other when the shell is hit, preventing the shell from of shattering. Using this information, scientists are studying this to learn how to create stronger products such as body armour.

Abalones are facing extinction

Wild abalones are facing extinction (the black abalone is Critically Endangered and the pinto abalone is Endangered) because of overfishing, increasing acidity of the ocean which erodes their shells, and the spread of the withering abalone syndrome which attacks the lining of the abalone’s digestive tract.

In trying to halt that decline of the abalone population, countries such as the United States and South Africa have enacted laws to prevent harvest of wild abalones. Even so, because of the high price of abalone (a full-sized poached red abalone can go for US$100 or more), abalone poachers continue to collect abalone to sell in the black market.

Elsewhere, abalone fisheries have been set up to meet the increasing demand for abalone meat. Main abalone farming regions today are found in China, Taiwan, Japan and Korea.

Korean abalone.
Korean abalone.

Credit

Abalone the escape artist

Unlike its land cousin, the snail, the abalone is nimble when escaping certain types of predators.

When the abalone is touched by a sea star, it twists its shell violently to dislodge the sea star’s tentacles. It then flees the scene at a rate faster than the slow-moving sea star.  Some even spit out viscous white mucus when fleeing.

[Caption: Watch how this abalone manages to escape from the sea star.]

Other responses to predators include clamping down on the surface so they can’t be easily pried away. However, this does not deter persistent predators such as otters and humans. Otters have been seen hacking abalone off its rock by hammering the shell at the rate of 45 blows in 15 seconds.

 

Come see live abalones at the S.E.A. Aquarium’s Discovery Touch Pool during the Gong Sea Fa Cai programme from 23 January to 22 February 2016.

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