19 invasive marine species arriving in the United States, including crabs, shellfish and starfish. Two researchers have researched these species and found that they are larger than members of their home. Some have increased by 40% after moving from the original environment to the new place. According to the researchers, this increase should not be associated with the latitude change or the time elapsed since the invasion. According to experts, these animals have increased due to the absence of predators and parasites. In addition, they point out that the reverse trend, that is, the decrease, only occurs in the case of a clam.