A Student Catches a Ray-Finned Fish from the Ocean and Notices

A student catches a ray-finned fish from the ocean and notices that attached to its flank is an equally long,snakelike organism.The attached organism has no external segmentation,no scales,a slimy substance on its surface,a round mouth surrounded by a sucker,a tongue,and two small eyes.The student thinks it might be a marine hagfish or a lamprey.Which feature excludes the organism from possibly being a lamprey?

A) elongated shape
B) lack of scales
C) a slimy substance on its surface
D) round mouth
E) tongue