The head (tolstolobic, lat. Hypophthalmichthys), a species of whitefish (Cyprinidae) belonging to the three species, white (H. molitrix) and gray (H. nobilis) tolstolobic or glavaš, and H. harmandi. This last species lives in Hainan and Vietnam.

The name Tolstolobic comes from the Russian Tolstoy lob in the meaning of the thick forehead.

All three species grow over half a meter long. Both white and gray tolstolobs are invasive species originating in Eastern Asia (Russia and China) where they are imported from various countries around the world, including H. molitrix and because of the control of algal blooms, but their influence has become negative due to the suppression of domestic species of fish . Gray and white differ in color rather than by anatomy, but they are not mutually mixed when mating in natural conditions. Gray is different from white because it has a bigger head.

The glaciers or tolstolobics are characterized by tasty meat, so they are important in human nutrition.