Task: Question Answering
Input (English): passage: Mantas evolved from bottom-dwelling stingrays, eventually developing more wing-like pectoral fins. M. birostris still has a vestigial remnant of a sting barb in the form of a caudal spine. The mouths of most rays lie on the underside of the head, while in mantas they are right at the front. Manta rays and devil rays are the only ray species that have evolved into filter feeders.
 question: do manta rays have barbs on their tails?
Output (English): No