guttate (GUHT-ayht) - adj., resembling or having the shape of a drop; spotted as if by drops.
vibrissa (vahy-BRIS-uh) (plural vibrissae) - n., any of the bristle-like sensitive hairs on the face of many mammals, a whisker; any of the specialized bristle-like feathers around the beak of certain insectivorous birds.
Guttate did not originally mean drop-shaped, as you might expect -- rather, it was borrowed in the 1820s from Latin guttatus, spotted, speckled (which in turn came from gutta, drop). Somehow the meaning shifted the other way. Vibrissa is more obvious: it was borrowed around 1693 from Medieval Latin vibrissa, nostril hair, from Latin vibrare, to shake -- the things that vibrate, in other words. Note, however, that while whiskers are indeed tactile organs, apparently the bird vibrissa are actually just there to help capture the little bugs. Go figure.
Deep under the river's calm surface, a guttate catfish cruised the muddy bottom, feeling for prey with its vibrissa.