A soft body, with or without a head, a muscular foot--- that's the mollusk. Some like this whelk, have a shell. But not all mollusks do. In fact, mollusks come in every shape. Just imagine, there are 80 to 100 thousand species of sea or land snails, shellfish of all sorts, octopi, and squid. They've conquered every environment,even a little humid. Some slide through the grass, others swim in the ocean, or else stick to[1] rocks.To live, sticking to things is the case with this giant clam[2]. An imposing[3] calcium shell that can measure 1 meters and 50 centimeters in length, and it makes it one of the biggest shellfish ever. This mollusk feeds by filtering water,catching miniscule animals. And here is a mollusk without shell, and it's usually called the "Spanish dancer". But its real name is seaslug. When it isn't dancing in the water, the slug feeds on microscopic organisms on the rock. And to do so, it possesses, like many mollusks, a rough tongue, called a " radula".The great, great grandparents of the mollusks already inhabited the ocean floor long beforedinosaurs saw the light of day. Among the oldest of them all are the nautilus. It has a good 30 tentacles. Its close cousin, the octopus, has only 8 to 10 arms, and it uses with real intelligence, since it has been discovered that these animals are gifted[4] with memory, and therefore are capable of learning.

软体动物

　　柔软的身体，有头或没头，强健的脚，这就是软体动物。有些象这只蛾螺是有壳的。但不是所有的都有。事实上，软体动物形态各异。想象一下，地球上有八到十万种陆地或海洋类蜗牛，各种贝类，章鱼和乌贼。它们征服了每一寸环境，甚至是小沼泽地。有些穿草丛，有些游海洋，或是粘在岩石上。这个大蚶就是粘在东西上生存的例证。它庞大的壳长1.5米，是最大的贝类动物之一。这个软体动物以过滤海水捕捉微生物为食。这是个没有壳的软体动物，通常被称为“西班牙舞娘”，它的真实名字是海蝓. 当它在水中舞蹈时，海蝓是在吃岩石上的极小微生物。象许多软体动物一样，它用叫做“齿舌”粗糙的舌头吃食。早在恐龙存在之前，软体动物的祖先已经在海底居住。最古老的是鹦鹉螺。它有30只触角。它的近亲：章鱼，有8到10只触角。这8到10只手极为灵巧。因为研究发现这些动物有非凡的记忆力，所以会学习。