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10 Interesting Facts About Mollusks

Friday, May 18th 2012. | Animal

Mollusk fact is an interesting topic on this post. Mollusks include all animals with or without soft shells, such as various types of snails, shellfish, and squid and their relatives. Mollusks are the second largest phylum in the animal kingdom after the phylum Arthropoda. Currently there are an estimated 75 thousand species, plus 35 thousand species in the fossil record. Mollusks live in marine, freshwater, brackish, and terrestrial. From the trough of the sea to the continent of high mountains, it’s easy even found around our homes. Here are 10 interesting mollusk facts.

Mollusk Fact 1

Mollusk Fact

Giant Mollusk

There are 80 000 species of mollusks alive, classified in the Gastropoda (snails and slugs), bivalves (mussels, oysters and clams), Cepahlopoda (squid, cuttlefish and octopus), Scaphopoda, Polyplacophora (chiton), Aplacophora, Monoplacophora, Caudofoveata. Because most mollusks have a hard shell, a lot of stone, and more than 35,000 known fossil species.

Mollusks have a network of external flexible covering called the mantle, well-developed circulatory and nervous systems. They reproduce sexually, have separate sexes or be hermaphroditic (such as snails and bivalves are many). Shell is made by the mantle by calcium carbonate extracted from water. It is used for floating or as a refuge. The mollusk body is made by the head, body and legs. Head may have tentacles and eyes. The mouth contains the radula, an organ is provided with several sets of grinding teeth. Anus and excretory hole open in the mantle cavity.

Mollusk Fact 2

Sea hare sea slugs are only out the money without. They often occur on coral reefs and colorful owned and eat coral polyps, sponges and sea anemones. Most shelled marine snails that live on or near the bottom of the sea, feeding on algae, bacteria and fungi that are found in rocks. In tidal areas, many carnivorous snails. Snails in the world is Australia trumpet (Syrinx aruanus), marine species from the north and west coast of Australia which can grow up to 77.2 cm (30 inches) shell length, while the meat weighing up to 18 kg (40 pounds). This eating starfish and sea cucumbers, and very rarely now, is being intensively collected.

Every woman of the sea slugs produce about 2,000 egg capsules and each capsule contains about 1,000 eggs. Capsules are sticky and adhere one to another, forming a “ball of the sea”. Egg capsule of about 1,000, about 30 offspring hatch, eat the remaining eggs and each other as well, so in the end of each capsule produces 10 new snails. Some snails tolerate different levels of salinity, which faced both in brackish and fresh water. Abalones is a snail with a breathing hole in the edge of the shell.

Mollusk Fact 3

Bivalves have a double shell, articulated through the ligaments are very strong and flexible, which can be relaxed to allow the opening of the shell, facilitating entry and exit of water. When the shell is attacked, the skin maintains tight muscles. Bivalves feed on organic material and detritus floating, sucked through a siphon frayed at the edges of the shell. Water is released through the siphon is smaller.

Some freshwater mussels release larvae called glochidia which floats on the water and attached to the gills of a fish called the bitterling. Larvae changed here in the small shellfish and fish begin to leave their lives at the bottom of the lake. In contrast, bitterling range eggs only in the mantle cavity of mussels, in which the developing eggs are protected.

The giant clam Tridacna form a symbiosis with algae Zooxanthella: algae living in shellfish tissue, which focuses light on a transparent cell which converts waste Zooxanthella from the host into sugars through photosynthesis. In this way, giant clams can be found only at depths to 20 m (66 ft) in the coral reef, where they can make the symbiotic algae photosynthesis 6. These mussels live at least 100 years and Tridacna gigas can be 1.37 m (4.5 ft) long, weighing 20 kg (44 pounds) (this is the world’s largest shelled mollusk). Tridacna is threatened, because they are heavily exploited, their meat appreciated.

The king of shells, shell edge has tentacles and eyes. When the eyes to detect predators, animals execute movements with a jet back suddenly let out the water from the mantle cavity.

Mollusk Fact 4

Cephalopod fossils are known from 500 million years ago. They have specialized tentacles around the mouth, complete with hat and hooks, and eyes are well developed. Funnel-shaped mantle cavity, is being developed to encourage the animal back at high speed, due to the sudden expulsion of water. Squid can reach 55 km (35 miles) per hour, and can jump from the water at this speed.

Abyssal squids can be more than 12 m (40 feet) and weigh up to 6 tons. They form the main food of sperm whales. It is estimated that sperm whales and seals eat every year about 10 million tons of squid.

Squid has a parrot-like beak, and all octopuses are venomous (some more than others). Octopus can not tolerate each other and mating is done through the tentacles. In males, the penis functions like tentacles, and through this groove tentacles, males transfer a spermatophore (sperm capsule) to the female. Females lay about 150,000 eggs kept by him for about 6 weeks until they hatch, when he died.

Octopus has eight tentacles, squids and cuttlefish have two additional, longer than the others, who sprang forward to grab the prey with their hats. Tentacles long stay in a resting position into the cavity under the eye of the beast. Squid and cuttlefish also have lateral fins. Octopuses have no shell, while cuttlefish and squid still keeps the inner shell, with a role in floatability. All squid have cromatophores skin that allows them to change the color and mimic their surroundings.

The most primitive living cephalopod, Nautilus, has 90 tentacles and the shell is fully developed, as in snails, used as a residence and for floatability.

Mollusk Fact 5

Chiton lives in shallow waters, they have eight overlapping calcareous plates on the back and the ventral part. The flow contains several pairs of gills. Chiton to feed at night, cutting the algae and other plant things with their toothed radula. When disturbed, chiton rolls like a porcupine.

Mollusk Fact 6

There are 70 species Caudofoveata, everything looks like a worm and feed on microorganisms and organic material floating on the sea floor. The body is covered by a protective hard scaly skin.

Scaphopoda live buried in sediments, have bilateral symmetry and shell held open at both ends. Thin edge out of the sand, and although the flow of water allows respiration and excretion. They eat the Foraminifera (a type of protozoa) to catch them with their trunks and tentacles and hit their heads with their radula. Solenogastra not have a shell and they never did. They look like flat worms and eat the polyps.

Mollusk Fact 7

Pearls and mother of pearl shells produced by mollusks. Pearl occurs when a foreign object, like a grain of sand or parasite remains between the two shells of a. The object wrapped by the calcium carbonate until it will be isolated from the body shell. By artificially introducing a small piece of material into the body shell, a small pearl is made in the command.

Mother-of-pearl, the shell’s interior materials, used in ornaments and wood embeddings. Pinctada shell, Trochus and Turbo were collected in the Pacific.

Mollusk act


Mollusk Fact 8

In the Mediterranean, 50 species of bivalves, 12 of the snail, and 13 of squid consumed by humans. 2.3 million tonnes of oysters are consumed each year. Oysters make 25% of mollusc farming, other species of these mussels, scallops and mussels. Up to 1.2 million tons of squid and octopus fishing each year, 50% by Japan.

Mollusk Fact 9

Mollusks have large neurons, and the sea hare used in the study of memory loss.

Mussels, squid and shellfish contain antibacterial and antiviral chemicals and freshwater mussels contain anti-cancer chemicals.

Mollusk Fact 10

Mollusk fact


This is last fact on these facts about mollusk post. Mollusks are threatened by contamination with heavy metals, bacteria from residues and waste water, and very sensitive to oil spills. Many impurities can reduce the filtering system of mollusks. Sea dykes, draining off from the estuary and tourism, impacts heavily on mollusks. This is interesting mollusk fact.

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