nurse shark
n. Any of various bottom-feeding sharks of the family Ginglymostomatidae, having long barbels near the mouth and feeding chiefly at night, especially Ginglymostoma cirratum of tropical and subtropical waters.
[From nurse, any of various kinds of dogfishes or sharks, alteration of earlier nusse, perhaps from earlier and dialectal huss, dogfish (by reanalysis of an huss, a dogfish as a nusse), from Middle English husk, of unknown origin.]