Piranha Attack

How big do Piranha actually get? This is the black type and to my knowledge the biggest flesh eating type. This is a medium sized one, but the vegetarian type gets much bigger. While one like this easily could snap finger by the joint and there every year is a lot of bites around a country like Guyana. This specific type despite its impressive set of teeth mostly bite people when they get handled out of water. Whether it be the fingers trying to recover a hook or someone not wearing proper footw