405_April_24

Barbels with taste buds have evolved in many other fishes (such as this largetooth beardie, Lotella rhacina ) that are nocturnal or live in deep or turbid waters.

The barbels of this bluestriped goatfish ( Upeneichthys lineatus) can be manipulated to sweep, dig and probe sand for signs of food.

compared with goatfish, we humans are under-performers when it comes to tasting: our tongues have 2,000-8,000 taste buds (the total number varies a lot among individuals and declines with age) and an average of only 2 taste buds per square millimetre of tongue surface. Taste buds completely encircle a goatfish’s barbels and the taste buds at each level of a barbel are monitored by separate nerves that connect to a unique part of the taste centre in the goatfish’s brain. This means that a goatfish

can accurately determine the depth at which food is hidden in the sand, whether it’s to the left or right, or the inside or outside of a barbel. Once detected, all of this information empowers the goatfish to precisely target a food item with its mouth. Barbels with taste buds have evolved independently in many different groups of fishes and are most elaborate among fish that feed on sandy seabeds or live in dark or turbid waters. Sharks such as epaulette, blind and

Goatfish have solved the problem of finding food buried in sand: following a signal from the taste buds on its barbels that indicates the precise location, the goatfish buries its head to capture its prey.

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DIVE LOG Australasia #405 - April ‘24