I didn't measure the length, but the scale said over 7lbs in weight. Had we decided to target these we could have easily caught hundreds each day, but they were really only incidental catches while drifting bait for catfish. The piranhas did not live in the deeper holes where the catfish were, so you knew as soon as you drifted past the deeper hole because the piranhas would tear your bait apart immediately. Despite trying to avoid them the whole time I think I landed around 6 or so and they were all over 5lbs except for one. They attacked lures as well but were hard to hook. We threw them back as the peacock bass were better for eating. I had Piranha on my last trip; they taste good but have a lot of bones.