Amazing Diversity in Fish Dentition

Since the ray finned fishes are the most speciose group of vertebrates it is not surprising they exhibit such a wide range of feeding structures and functions.  Here are just a few examples of their dental arrays.

Lampreys – Lack true jaws.  Lampreys start out their life cycle with a toothless mouth suited to filter feeding, and in the parasitic forms develop several circular rows of sharp teeth used for latching onto and a radula (center of oral disk) for rasping a hole in their prey.

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Sharks– teeth are triangular and razor sharp, those on the lower jaw have small serrated lateral cusps at the bases for enhanced cutting and tearing that is facilitated with strong jaw musculature and shaking motion of the head or chewing.  Sharks, unlike many of the more advanced fish species shown here, do not have pharyngeal jaws associated with their gill baskets.

Lungfish – have a tooth structure unique among the vertebrates: sturdy tooth plates called “Odontodes” that are used for grasping and crushing prey

Lungfish dentary plate (image from Nature)

Gar – rows of small villiform teeth for capturing and holding fishes in their elongated jaws while they manipulate the fish to a headfirst position for swallowing

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Bowfin – many sharp caniform, inward pointing teeth on the premaxilla, dentary and maxilla jaw bones for grasping and holding the prey (an extreme example of canine teeth in fish is shown in the African Goliath Tigerfish)

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Pike – (image in previous post) the long, sharply curved caniform teeth on the dentary are a prelude to a villainous array of cardiform teeth  on the premaxillary, basibranchials, last two pharygobranchials, vomer, palatines, and glossohyal bones

Grass Carp – the heavy pharyngeal teeth of these herbivores are used for shredding algae

grass carp pharyngeal teeth

Piranha  – teeth are triangular, razor sharp, with small lateral cusps at the bases like sharks

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River Redhorse – feed on sand-dwelling mollusks with sturdy teeth on lower pharyngeal jaws (characteristic of all ostariophysans whereas higher teleosts have pharyngeal teeth on lower and upper arches like the redear sunfish) used for crushing molluscs found in the bottom substrates

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Moxostoma carinatum pharyngeal arch

Flathead Catfish – gulp prey with large, non-protrusible mouth and hold with cardiform teeth, the largest patches of which are shown in this picture of a partial, disarticulated jaw, on the premaxillary (top of image) and anterior dentary (larger, semicircular structure at bottom of image) bones.  Gill arches show pharyngeal teeth, with pharyngeal tooth plates at the anterior, ventral symphysis of gill arches

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Largemouth Bass – have limited cardiform teeth on the medial jaw bones, but these are complimented by a large, protrusible mouth for engulfing prey

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Freshwater Drum – All other drum species are marine, but this one is native to larger waters in the Great Lakes and Mississippi River drainages.  (1st image focused on the anterior aspect of the jaw) Note the incisor-like anterior teeth on the anterior dentary for nipping prey off substrates, the molariform teeth on the heavy glossohyal bones, (2nd image focused on the posterior aspect of the jaw) the sturdy pharyngeal teeth on the gill arches for capturing and shredding prey, and the molar-like teeth on the pharyngeal tooth plate for crushing mollusk shells

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Ocean Pout – like many molluscivores have strong conical dentition on the anterior portion of their jaws for plucking mollusks from surfaces, and flattened, molariform teeth in marginal or pharyngeal jaws

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X-ray from Canadian Museum of Nature

Triggerfish (incisor-like dentition), Pufferfishes (teeth fused into parrotlike beak) – have powerful jaws to remove invertebrate prey (sponges, ascidians, coelenterates and chitons) from surfaces

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About the Author: Marc Kibbey is Assistant Curator of the OSUM Fish Division.

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