Does hardness of food affect the development of pharyngeal teeth of the black carp, Mylopharyngodon piceus (Pisces: Cyprinidae)?

Abstract

We investigated whether food type influences development of the pharyngeal crushing apparatus of black carp (Mylopharyngodon piceus, Cyprinidae). Fish fed a hard diet had average standard lengths and weights larger than those fed a soft diet; these observations in part could be related to differences in nutritional value of the two food types. The lower pharyngeal bones, which bear molariform teeth were examined using three dimensional computed tomography (CT) scans. After adjusting for differences in the standard length of the fish, the total volume and exterior surface areas of the pharyngeal teeth were greater in fish fed hard diets than in those fed soft diets.Total weights of the pharyngeal arches were less in the fish fed a soft diet than in those fed a hard diet. These results indicated that food type affects development of the pharyngeal crushing mill of black carp and therefore if black carp are produced for snail control, a hard diet should be provided from an as early time as possible in the production cycle.