The five introduced species, which has presented a serious threat to their new communities are zebra mussel, brown tree snake, the cane toad, kudzu, and the lamprey.
Due to the introduction of brown tree snakes, approximately 12 species of birds and 6 species of lizards have got extinct. The zebra mussels introduction has disrupted the freshwater ecosystems and has clogged the water intake structures.
Due to the introduction of kudzu, the whole region of the southern United States has become dominated by the plant. The introduction of cane toads has killed an ample amount of species without being getting killed themselves as they are poisonous and lacks predators. The introduction of lampreys has resulted in the decline of diversity as they lack predators and kill other species briskly.
Cat (Australia); lots of cats became feral and they reproduce very fast. They became the apex predator and the native species have no defense system for them, so the cats brought tens of species on the verge of extinction (mainly placental mammals). Fox (Australia); became an apex predator in the lack of competition, and damages the populations of native small placental mammals. Hair (Australia); reproduces much quicker than the native species of mammals, increased significantly in numbers, and out competes the native species for the food sources. African bee (the Americas); much more aggressive and stronger than the native bees and systematically kills their populations. Grey squirrel (Britain); reproduces quicker than the red squirrel, is bigger, and out competes for food, brought it on the verge of extinction.
También contienen fibras de tejido conectivo que les aporta su elasticidad característica. En el epitelio alveolar se pueden distinguir células planas de tipo I y células en forma de cubo del tipo II. Su función principal es mediar el intercambio gaseoso entre el aire y la sangre.
