鲨鱼既是个体最大的鱼类,也是海洋里的一霸.大鲨鱼一条往往重达几千斤,特大的还有一万几千斤的.一般市场上所能看到的都是小鲨,说小鲨鱼也不算小,最小的一条也有好几斤重.鲨鱼这一门类又统称为软骨鱼类,常见的有十多种,形态各异,有胎生的也有卵生的.它们共同的特点是一身灰色的大糙皮,用手摸就象擦铁锈用的砂布,大多数鱼鳃都是五道或七道缝,嘴都长在尖扁头下方,尾巴上翘如船舵.长的如猫头鼠脸的叫猫鲨、鼠鲨;尾巴特长的叫长尾鲨;头如榔头、两眼分别长在榔头一边的叫双髻鱼或相公帽、相公鲨;扁圆小尾巴状似琵琶的叫琵琶鲨;头顶一根锯的叫锯齿鲨;此外还有根据皮色斑纹、斑点 Sharks are both the largest individual fish, but also the sea in a tyrant .One big shark often weighs a few kilos, extra large there are ten thousand kilograms .In the general market can see are sharks, said Small sharks are not too small, the smallest one is also a few kilos.Sharks are also commonly referred to as cartilaginous fish, commonly seen in more than 10 different forms and viviparous ovums. Their common feature is a Large gray skin, touch with rub like emery cloth, most of the gills are five or seven seams, the mouth is long under the sharp flat head, tail upturned as a rudder. Mouse face called cat sharks, mouse sharks; long tail tail called long-tailed sharks; head like a hammer, two were long in the hammer side of the double-headed hamster or phase hat, phase shark; oblate small tail like lute called A pipa shark; a sawtooth overhead is called a sawtooth shark;