Bony fishes usually have five pairs of branchial arches, four of which bear gill rakers medially and gill lamellae laterally. Some have the fifth arch more or less modified into a pharyngeal bone bearing teeth. Cyprinid fishes, lacking true teeth in the oral cavity, have a well-developed dentition on this pair of gill-arch-derived pharyngeal bones. The presence and arrangement of these pharyngeal teeth is one of the important diagnostic characters of the family Cyprinidae.
Because pharyngeal teeth are composed of the hardest tissue of any found in fish and are very resistant to decay. they are frequently well preserved as remains in geological strata and archaeological sites. The study of pharyngeal teeth of cyprinid fishes can be very revealing. From the characteristics of the teeth we can tell much about the fish themselves and their living conditions.
The purpose of this volume is to offer SEM images of the pharyngeal dentitions of a wide range of cyprinids for the first time, based on materials preserved mainly at the Lake Biwa Museum in Japan and the Institute of Hydrobiology, Chinese Academy of Sciences, and to show how the pharyngeal dentition is expressed in various groups (subfamilies) of cyprinids, but not to describe differences among individual species. To accomplish this, the morphogenesis of the pharyngeal teeth of several cyprinids is described for the first time. Based on these data and earlier descriptions, a new categorization of ontogenetic patterns of these teeth is proposed, which serves as the basis for describing the teeth of a wide range of cyprinids representing every subfamily.