The distribution of the teeth in blue-gill sunfish, Lepomis macrochirus

It has long been known that there is considerable correlation between the mode of food and the type of dentition a fish has. The blue-gill sunfish , Lepomis macrochirus, feeds upon very different kinds of food, e. g. zooplankton , egg, larvae, juvenile and water plant. This paper is a report on the distribution of the teeth and the growth of the dentition from the larval to adult stage in the blue-gill sunfish. There are conical teeth on the pre-maxillary, vomer , palatine, dentary, hypobranchial, ceratobranchial, epibranchial, pharyngobranchial, upper pharyngeal and lower pharyngeal bones of the young and adult blue-gill sunfish. The first indication of conical teeth on the upper and lower pharyngeal bones was observed in about 8-10 mm in standard length (SL) , on the pre-maxillary and dentary when the fish became about 10-11 mm SL, on the vomer and palatine about 11-12 mm SL. and on the branchial arch (hypobranchial, ceratobranchial , epibranchial) about 13-18mm SL. The fully developed dentition was found in the mouth and pharynx of specimens exceeding 18-20 mm SL . From the juvenile to the adult stage, the total number of the teeth on these bones and the individual tooth length increased with age. The total number of teeth was about 30000 in the in the adult fish, 90-100 mm SL. These conical teeth were hinged to the supporting bones by connective tissue. The tooth can be folded back into the mouth. When the prey is large and agile. it must be prevented from escaping. The teeth inged by the ligament o the bone serve this function .