Mollusks
Mollusks are the second most diverse animal group after the arthropods, and they include animals with almost nothing visibly in common: snails, clams, mussels, squid, cuttlefish and…
About mollusks
Mollusks are the second most diverse animal group after the arthropods, and they include animals with almost nothing visibly in common: snails, clams, mussels, squid, cuttlefish and octopuses. Most produce a shell of calcium carbonate secreted by a fold of tissue called the mantle, and the ones that abandoned it — the octopuses and squid — went in a completely different direction, towards speed, camouflage and the most sophisticated nervous systems of any invertebrate. The group includes filter feeders that clean enormous volumes of water, grazers that shape entire rocky shorelines, and predators that drill through the shells of other mollusks. Shell-forming species are directly exposed to ocean acidification, which makes building and maintaining a shell progressively harder.
Mollusks with a full profile
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Where mollusks are recorded
| Region | Climate | Species |
|---|---|---|
| Arabia & the Middle East | Blistering desert heat with very little rain. | 28 |
| Japan & Korea | Four seasons, from the snowy north to the mild south. | 17 |
| Arctic & Tundra | Long frozen winters far below 0°C and a short, cool summer. | 14 |
| Coral Reefs & Oceans | Warm, sunlit tropical seas in the shallows; cold and dark in the deep. | 11 |
| American South & Everglades | Hot, humid and subtropical with heavy summer storms. | 11 |
| Mainland Southeast Asia | Hot and tropical with a heavy monsoon. | 7 |
| New Zealand | Mild, wet and temperate. | 6 |
| Caribbean Islands | Warm, breezy and tropical all year. | 5 |
| Antarctica | Earth's coldest, windiest place, plunging to −60°C. | 4 |
| Mexico & Central America | Warm and tropical with a strong rainy season. | 4 |
| Southern Africa | Warm and sunny with a summer rainy season. | 4 |
| Southeast Asian Jungle | Hot and steamy with monsoon downpours. | 3 |
| European Woodlands | Mild, temperate seasons with cool rain and gentle summers. | 3 |
| Eastern North America | Four full seasons — humid summers and snowy winters. | 3 |
| West Africa | Hot and humid by the coast, drier toward the Sahel. | 3 |
| Himalayas & High Asia | Bitterly cold with thin air, snow and fierce winds. | 2 |
| Australian Outback | Hot, dry and blazing-bright across the interior. | 2 |
| China's Bamboo Forests | Cool, misty and damp in the mountain forests. | 2 |
| Amazon Rainforest | Warm and extremely humid with heavy rainfall all year round. | 1 |
| North American Desert | Scorching dry days and surprisingly cool nights. | 1 |
| Indian Subcontinent | Hot, ruled by the dramatic monsoon rains. | 1 |
| Siberian Taiga | Brutally cold winters and short, mild summers. | 1 |