Simplify the following text for a Grade 2 native English-speaking person.
Original: Other types of rays also referred to as stingrays are the river stingrays ( family Potamotrygonidae ) , the round stingrays ( families Urolophidae and Urotrygonidae ) , the sixgill stingray ( family Hexatrygonidae ) , and the deepwater stingray ( family Plesiobatidae ) . For clarity , the members of the family Dasyatidae are sometimes called whip-tail stingrays .
Simplified: They give birth to baby stingrays .