They'll destroy you, but it ain't nothing, it ain't nothing to me

Today in the lab:

Grad Student: Do you ever watch that show River Monsters?

Me: I've heard of it, but have never seen an episode, even though it seems like it'd be interesting.

Grad Student: Well, I saw this episode the other night where they were after some introduced fish in Papua New Guinea that bites peoples' testicles off.

Me: What? Like skinny dippers? I don't think they could bite that hard through any clothing.

Grad Student: The natives go down and bathe or swim in the river or whatever, and these fish come along and bite off their sacks. It happened at least twice, and one of the guys died. He bled out after it happened.

Me: It wouldn't take long to bleed out if that really did happen.

Undergraduate: Is there a lot of blood flow to that part of the body?

Me: There can be, if my morning wood is any indication.