Journal of Dental Research, Vol 63, 1140-1146, Copyright © 1984 by International & American Associations for Dental Research Online Journals
Larval vs. adult pharyngeal dentition in some Japanese cyprinid fishes
T. Nakajima
The development of the pharyngeal dentition was examined in 13 species of
five subfamilies of the family Cyprinidae. A previously described
difference between the larval and adult dentition in Gnathopogon
caerulescens was observed in 11 species of Gobioinae, Cyprininae,
Leuciscinae, and Danioinae, but was not seen in two species of
Acheilognathinae. The adult dentition is usually complete by the later
larval or juvenile period. In the adult dentition, the functioning teeth
are generally shed at each position, when the replacement tooth has been
ankylosed to the bone, or when the germ of that tooth has grown
sufficiently. In the larval dentition, however, the replacement tooth is
ankylosed medial to the functioning tooth, so the older functioning tooth
is retained after ankylosis of the replacement tooth. That is why the
dentigerous surface of the bone grows rapidly during the larval period.
Each tooth row represents a single replacement wave. The distribution and
pattern of the central teeth are exactly the same in all types of the
larval dentition. However, those of the anterior teeth vary between and
within different species. The larval dentition develops into the major row
of the adult dentition through tooth replacements. The number of tooth
families in the larval dentition is completely consistent with the tooth
number of the major row in the adult dentition. Therefore, the number of
major row teeth owes its variation to that in the appearance pattern of the
anterior teeth.
