Earlier this month, scientists in Thailand's Mae Klong River reeled in a massive stingray—possibly the world's largest freshwater fish—as well as a whole lot of reader curiosity.

He also wondered whether this giant freshwater stingray is venomous, and if its spines grow with age.

So, for Weird Animal Question of the Week, we dove in to learn more about the ancient, arresting, and dizzyingly diverse group of fish called rays and skates.

First off, the recently caught giant freshwater stingray, a species called Himantura polylepis or H. chaophraya, belongs to the Dasyatidae family, which is known for its venomous spines. The number of spines varies by species, but stingrays in this family typically have one, and it grows along