Important information about the health of the Great Barrier Reef

Teeth of the Great Barrier Reef

Parrotfish

A Parrotfish’s teeth have evolved over time into a specialized tool for scraping coral.

There is a wide variety of teeth found on the creatures that live on the Great Barrier Reef. Most people would be aware of the dentition of sharks and other predators, but there are many different dental styles that allow the myriad of marine creatures survive.

Fish teeth have evolved from scales that covered the lips of primitive fish. They are made up of a bonelike substance called dentine covered with enamel. Like our teeth, they have a pulp cavity in the center containing blood vessels and nerves. Firstly, it’s important to realize that teeth in marine fishes don’t just occur on their jaws. They can be on the palate, the branchial arches, and even on the tongue and down the throat! Most of the early fishes have teeth that are all similar in shape and size (a style called homodont) . The shape depends on how the teeth are used. In most fishes they are simple cones and function to prevent slippery prey from escaping.

Shark and other predators’ teeth, as we well know, are triangular in shape, with a serrated edge, designed for slicing flesh into edible chunks. Fish such as the ubiquitous Hump-headed Maori Wrasse and sting rays, however, have strong crunching cones, designed to crunch up hard bodied creatures like shellfish and molluscs. Butterfly fish have evolved long thin teeth, like the bristles of a toothbrush, which are excellent for removing coral polyps and other invertebrates from the marine sub strata.

Catfish have multiple rows of tightly packed short teeth, that grip hold of food like two pads of sandpaper. Their teeth are often referred to as cardiform. Parrotfish are reknowned algae feeders. Over the course of time, their teeth have shrunk and moved forward on to the front of the jaw bone, creating a very useful tool for scraping the algae of the surface of the coral. A hagfish uses the rasping teeth on its tongue to bore holes in its victims and drain their blood whilst sawfish have long, flat beaks with a row of weapon like tooth projections in each jaw that can cut their prey in half.

Teeth are also very important in fossil history, as they preserve so well. Some of the largest marine fish teeth ever found come from the ancestor of the great white shark, called Megalodon. It’s teeth have been measured at nearly 15cm long.

Posted in All Marine Life