Wrasse tend to live in areas where there is plenty of weed. When they are threatened they can dive into them and stay out of sight until the danger is past. Over thousands of years their skin colour has changed to take advantage of this, turning several shades of green and brown so that they blend into the background and are even harder to spot. This particular type of defensive strategy is known as camouflage.
Sharp spines:
These are placed in the dorsal fin and make small wrasse much harder to swallow, both for diving birds like cormorants and predatory fish such as bass. Bigger wrasse (they grow to about 14 lbs in weight) only need to worry about creatures such as seals and sharks.
Powerful tail and fins:
Because the wrasse depends on its camouflage it doesn’t need to be the fastest long distance swimmer in the world. What it does need to be is a powerful sprinter. That way, if it is caught in the open, it can get its head down and charge for the nearest cover. Most experienced anglers will tell you that that is the first thing a hooked wrasse will do!
Pharyngeal teeth:
With shellfish and crustaceans – creatures whose skeletons are on the outside of their bodies – forming a major part of their diet, wrasse have evolved a second set of teeth in their throat. These are basically crushing plates to grind up any hard objects like shell. In this way the wrasse can, for example, crush the shell of a limpet to a fine powder and then spit it out, swallowing only the tasty bit that is left behind.
Strong, rubbery lips and thickened blunt teeth:
Weed tends to be prolific in rocky areas so that is where wrasse choose to live. In such areas one source of food is shellfish, which can range from mussels and dog whelks to limpets. In response to this the powerful jaws and teeth of the wrasse have evolved to enable it to pluck a limpet from the rocks. If you have ever tried to pull one off you will know how difficult that is. However to succeed the wrasse has got to slide its teeth under the shell of the limpet before it can seal itself securely to the rocks. To do that the fish has got to have very strong teeth and lips which can endure the occasional mistake.
