Koi fish do have teeth, but their dental structure is vastly different from that of humans. Here’s a detailed breakdown of koi teeth:
Tooth Location and Naming
Koi teeth are called "pharyngeal teeth," which grow in the throat rather than the oral cavity. This unique structure forms from "biting plates" evolved from the pharyngeal bones in the skull.
Tooth Arrangement and Function
- V-shaped Pattern: 5 teeth on each side (10 total), arranged in 3 rows: 3 main teeth in Row A and 1 auxiliary tooth in each of Rows B/C.
- Structure: Main teeth have larger crowns with crescent-shaped biting surfaces, while auxiliary teeth are smaller but still aid in chewing.
- Function: Though their mouth edges lack teeth, well-developed pharyngeal teeth allow them to grind food.
Tooth Replacement Phenomenon
Koi go through a tooth replacement process. Shed teeth may appear at the bottom of the fish tank—an observable sign for breeders. There are cases where overfeeding has been linked to tooth loss.
Relationship to Feeding Ability
Despite pharyngeal teeth, koi can’t chew tough foods (like aquatic plants). Their esophagus, which extends 5 times the body length, evolves to meet digestive needs.