The term 'little fish' can refer to a variety of species, including MINNOW (6 letters), FRY (3 letters), SARDINE (7 letters), and guppy (5 letters). Minnows are small freshwater fish that are often used as bait. FRY are newly hatched fish that are still dependent on their parents for food. Sardines are small, oily fish that are often canned and eaten as a snack. Guppies are small tropical fish that are popular in home aquariums.