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10 Amazing Mollusks: Facts and Photos


The author is a research enthusiast. She studied botany and zoology as major subjects in her bachelor's program.

Chinese cowry or Ovatipsa Chinensis

Chinese cowry or Ovatipsa Chinensis

Phylum Mollusca

Mollusks are the second-largest phylum of invertebrate and the largest marine phylum—comprising 23% of all marine organisms. They have diverse natures and different habitats, anatomical structures, behavior, and size. The most distinct structures of mollusks are a mantle, radula (a structure used for feeding), and the structure of the nervous system. Here are the photos and facts of 10 incredible marine mollusks:

1. Abalone—Commonly Known as Ear Shell

Abalone is a marine water mollusk that belongs to the genus Haliotis. It is a marine snail, and its shell has an open spiral structure. The inner layer is composed of 'nacre' also known as "mother-of-pearl" which makes the shell a strong and iridescent structure. The shape of the shell is convex and made up of calcium carbonate tiles which are microscopic and look like bricks. It contains several open respiratory pores in a row near the outer edge. Red abalone is the largest species reaching the size of 30 centimeters.

Living abalone showing epipodium and tentacles, in a display tank at California.

Living abalone showing epipodium and tentacles, in a display tank at California.

The flesh of abalones is edible and widely considered to be the desired food. Abalones are farmed in China, Korea, Taiwan, and Japan. In China, abalones are considered luxury items and reserved for special occasions.

2. Red-lined Bubble Snail

The red-lined bubble snail is a marine gastropod mollusk and belongs to the order Bullina. It is found in the sublittoral zone of the Indo-Pacific. It can reach a maximum size of 25 mm. This snail contains a milky-white mantle with blue edges, and two black eyes can be seen on the head. The shell is bubble-shaped and thin that contains reddish-brown bands with white background. It can retract completely into the shell and feed on polychaete worms.

3. Sea Hares

Sea hares are sea snails with shells, but because of their large size and rounded body—with large rhinophores on the head—resemble them with rabbit or hare. Aplysia Vaccaria—the Californian black sea hare is the largest living gastropod. They contain an atrophied inner shell which is soft in many species. Sea hares live in intertidal rock pools and areas that are sheltered from rough currents. Some species of sea hares spout ink when attacked or disturbed, and this ink is extracted by their algal food. Releasing ink is because of their gland known as the "purple gland" which is present on the top of the mantle cavity and gives off red or purple fluid.

The black sea hare is an extremely large gastropod. The longest recorded growth is 93 cm when crawling and weighed 14 kg. This species of sea hare is incapable of producing ink. It is protected by a secreted toxin that is sufficient to discourage predation.

4. Conch

Conches are large-sized sea snails with a high spire (a part of the shell of a snail) and a noticeable siphonal canal (the shell comes to a noticeable end at both ends). They contain long eyestalks and a narrow aperture. A foot ending is present in a sickle-shaped, pointed operculum which is used for propelling forward. The shells are spirally constructed, and their growth can be dextral (right-handed) or sinistral (left-handed). The shells of the conchs are used as musical instruments and for decoration. They are found along the beds of seagrass.

5. Sea Butterflies

Sea butterflies are actually small pelagic sea snails that float and swim freely in the water. There are no shells and gills in several families and instead of foot, two wing-like lobes are present which are used for slow flapping movement. The shell is colorless and fragile—vary widely in shape: coiled, globulous, triangular, or needle-like. They fly through the water with the help of their wing-like parapodia (lateral outgrowths from the body). They are an important source of food for sea birds, whales, and some fishes. But if some species of sea butterflies are consumed by fishes in a large quantity; it may lead to a 'black gut" that renders the fishes unmarketable.


6. Reaper Cuttlefish

Reaper cuttlefish, also known as the red cuttlefish, is a species of cuttlefish native to the southwestern Pacific Ocean. The scientific name is Sepia Mestus and belongs to the family sepiidae. The red body of the cuttlefish contains dark blotches and yellow coloration around the eyes. There are small organs in the skin known as chromatophores which allow it to blend the skin texture with the environment. The special feature of the red cuttlefish is camouflage which is achieved by changing skin color or texture.

Interesting Video About Adopted Camouflage of Cuttlefish

7. Cowries

Cowries are sea snails, marine gastropods that belong to the family Cypraeidae. The shell is egg-shaped, smooth, and shiny. The spire is not visible in the adult shell but can be seen in young specimens. The word 'cowrie' comes from Hindi and is found abundantly in the Indian Ocean. The shell of the cowries was used as money in the old days. It was used as money in ancient China and Africa. The small cowry shells were used as a teaching aid in school for counting, adding, and subtracting.

8. Banana Slugs

Banana slugs are North American terrestrial slugs that belong to the family Ariolimacidae. They are bright yellow that gave them the common name 'banana slug'. Some species may also have black spots on their body. Their color is also an indicator of their age and health. These slugs have two pairs of tentacles which they use as sensory organs. The upper pair detects light or movement, and the lower pair detects chemicals. The interesting fact is when a predator attacks tentacles, the slug can grow a new one. To combat the problem of dehydration, they excrete a thick layer of mucus around their body. This slime also contains pheromones to attract mates.

The mucus contains chemicals that can numb the tongue of a predator. Garter snakes, raccoons, goose, and ducks feed on these slugs. They can grow up to 25 centimeters long and is the second-largest species of terrestrial slugs. Banana slugs decompose the dead animals and plants and recycle them into the soil humus.

9. Flamingo Tounge Snail

The flamingo tongue snail (Cyphoma Gibbosum) is a species of small, bright-colored sea snails that belong to the family Ovulidae. They are bright orange-yellow with black spots. This color is because of the live mantle tissues that cover the shell. Many scuba divers and snorkelers collect them because of the bright-color shell, but in reality, it is not the color of the shell but the tissues above it. They feed on the living tissues of the soft corals, and females lay eggs on the corals, and larvae hatch after 10 days. The shell is elongated, and the surface is smooth and shiny.

10. Butterfly Chiton

Cryptoconchus porosus—the butterfly chiton is a species of chiton in the family Acanthochitonidae. It has a shell composed of eight plates or valves. The anterior and crescent-shaped plate is known as the "head plate", and the posterior is known as the "anal plate". The young specimen may contain seven valves, and these are covered by a girdle. The girdle is fleshy with short bristles that protrude from 18 pores, which are present in two rows from head to tail. It is native to New Zealand and can reach a length of 45–75 millimeters.

Butterfly Chiton

Butterfly Chiton



EK Jadoon (author) from Abbottabad Pakistan on May 25, 2021:

Thanks for your visit, Rozlin.

Stay safe and healthy...

Rozlin from UAE on May 24, 2021:

Well explained article on mollusks.

EK Jadoon (author) from Abbottabad Pakistan on May 24, 2021:

Thanks for your kind words, Amara. I am glad that you liked it.

EK Jadoon (author) from Abbottabad Pakistan on May 24, 2021:

Eman Sehar, I appreciate your visit. Thanks for stopping by.

Amara from Pakistan on May 24, 2021:

Its a very well written, and interesting article EK.. Also informative one.. Keep up good work.. ;-)

Nian from Pakistan on May 24, 2021:

Sea butterflies are amazing creature. Very Interesting article!

EK Jadoon (author) from Abbottabad Pakistan on May 24, 2021:

I appreciate your kind words, Misbah. These all are amazing creation of Allah. Thanks for your visit.

Stay blessed...

Misbah Sheikh from The World of Poets on May 24, 2021:

Very interesting, detailed, and informational hub, dear sister. I enjoyed the read. Flamingo Tounge Snail is a beautiful and glowing creature, I liked it. The colors of Sea Hares are amazing. They look so pretty. The video you shared is also very nice. Thanks a lot for sharing your knowledge. Allah Bless you.

Blessings and Love

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