Interactions

NAPOLEON WRASSE AS A PREDATOR:
Interacting with other species is an important feature to every organism's life.  Many times, they interact with each other in order to obtain food.  Every organism belongs to a food chain and, within this food chain, an organism may be considered a predator, prey, or sometimes both. Being a predator means they eat other organisms and, if an organism is considered prey, then it is being eaten by the predator (Cain et al. 2008). The Napoleon Wrasse is considered both a predator and prey because it feeds on other animals and other animals feed on it. In order to survive, it must find its own food.  The typical diet of the Cheilinus undulatus consists of mollusks, fish, echinoderms, sea urchins, crustaceans, and invertebrates (Scales 2005). This enormous fish is also known to eat toxic animals (Protect 2009)! This means the Napoleon Wrasse is able to feed on the crown-of-thorns starfish, sea hares, and boxfish even though they contain toxic substances.  They are able to do so because they have thick lips that absorb the spines of the toxic creatures. They also have strong teeth in their throats to help break down the hard calcium carbonate shells of organisms they eat (Shedd 2006).

NAPOLEON WRASSE AS PREY:
Although the Cheilinus undulatus is able to survive off of a variety of organisms, there are still a few organisms that prey upon them. There aren't many that are willing to prey upon a large organism, but the ones that are willing to take a chance are large reef sharks and humans, which are the major predators of the Napoleon Wrasse. Because this organism is so large, only large and powerful animals are able to prey on it, for example, the sharks (Bester 2013).  Humans, the major predator of this glorious reef fish, are the reason why the Napoleon Wrasse is considered "endangered" according to the IUCN Red List of Threatened Species (2004). In order to retrive these large fish, many fishermen fish using cyanide which is very harmful to not only the ecosystems, but the organisms living within them as well (Scales 2005). Because of this, humans are regarded as predators because they enjoy eating the flesh of the fish. It is a luxury item found in several markets in Hong Kong and can be quite expensive. Sometimes the flesh of this fish can cost up to one hundred US dollars for one kilogram (Bester 2013)! 


MUTUALISM:
The Napoleon Wrasse is able to form mutualistic relationships with other organisms within their environment. A mutualistic relationship is one where both organism involved benefit (Cain et al. 2008). The Napoleon Wrasse establishes a relationship with a small remora fish, which is called a "cleaner," who remove parasites and other harmful particles from the Wrasse.  In return, the remora fish gets a free ride and is able to collect food scraps while riding (Leao 2002).  To the left is an image demonstrating this relationship.  Both organisms benefit, making this a perfect example of a mutualistic relationship!

INTERACTING WITH HUMANS:
Lastly, one major observation by divers who came in contact with the fish is that they are very interactive with humans. According to Tyrone Canning, a diver who won the Austrian Ultimate Diver Competition, claims that a Napoleon Wrasse will exhibit behavior similar to the behavior of dogs when they want to be pet (Protect 2009). It is quite amazing that these large fish are so interactive with humans. They love the attention and if they don't get it right away, they'll keep asking for it!  The Napoleon Wrasse is a very fascinating creature and impacts the reef ecosystems dramatically.  These attention grabbing and social fish are a dominant organism in the marine environments.

Continue to Facts to learn how the Napoleon Wrasse surprises us even more!

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