Green abalone

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Green abalone
Haliotis tuberculata coccinea off Tenerife

Haliotis tuberculata coccinea off Tenerife

Systematics
Subclass : Orthogastropoda
Order : Vetigastropoda
Superfamily : Haliotoidea
Family : Haliotidae
Genre : Abalone ( Haliotis )
Type : Green abalone
Scientific name
Haliotis tuberculata
Linnaeus , 1758

The abalone abalone or abalone ( Haliotis tuberculata ) is a marine snail from the abalone family that lives in the eastern Atlantic and the Mediterranean . It is collected as seafood in its range and is endangered in places due to overexploitation .

features

In adult Haliotis tuberculata , the flat, ear-shaped housing is around 10 cm long and around 6.5 cm wide. The individual turns increase in width very quickly, so that most of the housing consists of the last half turn. On the outer edge of the bowl there is a row of 5 to 7 slightly raised holes through which short siphons from the jacket direct the water to the outside. As the snail grows, it forms another hole in the new housing section, while old holes are closed. The outside of the shell is green, gray-brown or reddish. As with other abalones, there is mother-of-pearl on the inside of the shell . The snail is able to form pearls around foreign bodies . An operculum is missing.

The snail is black. The epipodium located between the foot and the mantle is provided with numerous greenish, tentacle-like appendages.

The outside of the shell is usually covered with numerous encrusting organisms such as B. with bog animals , hydroids or algae, which helps camouflage the snail.

Distribution and way of life

The abalone occurs in the Mediterranean Sea as well as on the African and European coasts of the Atlantic Ocean from the Canary Islands to the Channel Islands in the English Channel . It lives on the shallow water of the intertidal zone up to a depth of about 25 meters on rocky ground, where it can suck on the hard substrate, but also in seagrass meadows , mostly under stones. The snail grazes the algae from the underground, preferably green algae such as sea ​​lettuce , but also red algae , including Jania rubens . The food affects the color of the casing.

Life cycle

The abalone abalone is separate sexes with external fertilization. The sexual maturity is reached cm from the males at the age of about 2 years at a barrel length of 2.5 to 4 cm, and the females at the age of about 3 years at a barrel length of 3.8 to 5.4. In late summer, the eggs and sperm are released into the open water, where fertilization takes place. After fertilization, the approximately 200 µm large egg cells develop into free-swimming Veliger larvae within 12 hours via a brief trochophoric stage, which lead a pelagic life until metamorphosis into a crawling snail .

The abalone as a seafood

The abalone is collected for its meat and sold as a delicacy . Since the second half of the 19th century, the stocks have decreased sharply due to overuse. In British waters, abalones 9 cm or more in length may only be collected from January to April on the new moon and the following two days.

literature

Individual evidence

  1. ↑ G. Courtois de Vicxose, MP Viera, A. Bilbao, MS Izquierdo (2007): Embryonic and larval development of Haliotis tuberculata coccinea reeve: an indexed micro-photographic sequence (PDF; 406 kB) . Journal of Shellfish Research 26 (3), pp. 847-854.

Web links

Commons : Green Abalone  - Collection of images, videos, and audio files