INTRODUCTION
Clown fish refer to 28 species of fish that are living around tropical coral reefs found in the warm water Indian, Pacific Oceans and the Red Sea. Here are some of them. Since the famous Disney movie Finding Nemo, the popularity of the clown fish increased and they are being breed by human. (Nemo is the Occelaris sp.) The Oceans, Reefs & Aquariums (ORA) is the leader in captive bred clownfish. Below is the pictures of the clown fish species with some addition developed by the ORA.
KEY SENSES
1. SENSE OF SMELL
Like people, fish have noses. Water flows through holes called nares into two chambers. Each chamber contains a rose-shaped structure called a rosette. Odor molecules stick to cells on the rosette called neurons. Those neurons then shoot a quick signal to the brain. That’s how a fish detects a scent.
Upon hatching, baby clownfirsh rise up to the sea’s surface and begin the planktonic stage (floating on the sea) for about 11-12 days. Then, they will use their sense of smell to find their way home. They swim toward the scent of leaves from the islands’ trees. They also detect odors to find food, avoid predators and prepare for mating.
(!!) The sense of smell worsen as the water becomes more acidic! At the current rate, clown fish might lose their ability to ‘go back home’ and avoiding predator by the end of the century! 
2. SENSE OF HEARING
For clown fish, the ability to hear is crucial as it makes them able to detect and avoid predator-rich coral reefs during the daytime (coral reefs are home to many species that can feed on small clownfish). They do this by monitoring the sounds of animals on the reef, most of which are predators to something just a centimetre in length.
(!!) Researchs show that clown fish in more acidic water showed no preference for moving away from threatening sound, while those exposed to normal levels of acidity move away from the perceived danger source. The acidity doesn’t seem to physically damage the fish’s ears, so maybe the damage is neurological, or maybe they are “stressed by the higher acidity and do not behave as they otherwise would.” This could seriously impact their survival in the long term.
BODY STRUCTURE
RANGE OF MOTION
It can freely move to any direction by moving its tail to move forward and side fins to help them steer.
A journal said that clown fish performed a bizarre little wiggle dance, flapping its fins while dodging and turning.
That creates fresh water circulation for the stationary anemone, allowing it to access more oxygenated water, speed up its metabolism, and grow faster. That’s also good news for the clown fish, which have more room to hide within the anemone.
SYMBIOSIS MUTUALISM WITH SEA ANEMONES
Symbiosis describes the special relationship between clown fish and sea anemones. They are the only fish that do not get stung by the tentacles of the sea anemone. Clown fish have a slimy mucus covering that protects them from the sea anemone. However, if this covering is wiped off of a clown fish, it will get stung and possibly be killed when it returns home to the anemone. The clown fish and the sea anemone help each other survive in the ocean. The clown fish, while being provided with food, cleans away fish and algae leftovers from the anemone. In addition, the sea anemones are given better water circulation because the clown fish fan their fins while swimming about.
(The video below is really good in showing the movement of different species of clown fish and different species of sea anemone, it also has part where the clown fish is trying to scare away human diver in order to protect the sea anemone)
INTERESTING FACTS
- HERMAPHRODITE (an organism that has reproductive organs normally associated with both male and female sexes)
In a group of clownfish, there is a strict hierarchy of dominance. The largest and most aggressive female is found at the top. Only two clownfish, a male and a female, in a group reproduce through external fertilization. The clownfish are hermaphrodites, meaning that they develop into males first, and when they mature, they become females. Also, as mentioned earlier, more than one clownfish is able to live in a sea anemone. If the female clownfish is removed from the group, such as by death, one of the largest and most dominant males would become a female. The rest of the remaining males will move up a rank on the hierarchy.
- STING PROTECTION
The clown fish is also famous for it’s seeming immunity to the stings of the sea anemone. Most clown fish are found either in or around sea anemones which the clown fish inhabits both for protection from predators but also the readiness of food.
OTHER FACTS
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Pomacentridae
Genus: Amphiprion
Size (L): 10cm – 18cm (4in – 7in)
Life Span: 4 – 8 years
Colour: Black, White, Orange, Red, Yellow
Diet: Omnivore
Favourite Food: Algae
Habitat: Tropical coral reefs
Main Prey: Algae, Plankton, Molluscs
Predators: Fish, Eels, Sharks
3D Project 3
Research: Clown Fish (aNEMOnefish)
In Class: The Nemo Movement
(coming soon)
Resources:
Animals, A. (n.d.). Clown Fish. Retrieved March 8, 2017, from https://a-z-animals.com/animals/clown-fish/
Hogan, T. (n.d.). Home. Retrieved March 8, 2017, from http://www.dive-the-world.com/creatures-clownfish.php
Investigation. (n.d.). Retrieved March 8, 2017, from http://tolweb.org/treehouses/?treehouse_id=3390
Leader, J. (2013, March 01). Clownfish, Sea Anemone Relationship: Fish Do Wiggle Dance To Help Out Host. Retrieved March 8, 2017, from http://www.huffingtonpost.com/2013/03/01/clownfish-sea-anemone-wiggle-dance_n_2789711.html
Increased CO2 Causes Clownfish to Lose Sense of Smell, Swim Toward Predators. (2010, July 14). Retrieved March 8, 2017, from http://worldgreen.org/increased-co2-causes-clownfish-to-lose-sense-of-smell-swim-toward-predators/
Kwok, R. (2015, November 01). When the nose no longer knows. Retrieved March 8, 2017, from https://www.sciencenewsforstudents.org/article/when-nose-no-longer-knows
Clownfish risk going deaf. (n.d.). Retrieved March 8, 2017, from http://www.hear-it.org/clownfish-risk-going-deaf
Richard, M. G. (2011, June 01). Ocean acidification makes clownfish go deaf (poor Nemo can’t hear predators anymore…). Retrieved March 8, 2017, from http://www.treehugger.com/clean-technology/ocean-acidification-makes-clownfish-go-deaf-poor-nemo-cant-hear-predators-anymore.html
Image credits:
http://s967.photobucket.com/user/oceanseeker/media/SHOP/CLOWNFISH-LOWRES.jpg.html
http://s967.photobucket.com/user/oceanseeker/media/SHOP/CLOWNFISH-LOWRES.jpg.html
https://image.slidesharecdn.com/clownfish-130530023920-phpapp01/95/clown-fish-3-638.jpg?cb=1369882379
https://www.google.com.sg/imgres?imgurl=https%3A%2F%2Fs-media-cache-ak0.pinimg.com%2F736x%2F93%2Fb0%2Fc5%2F93b0c58dd20a2045db6a43735d36f184.jpg&imgrefurl=https%3A%2F%2Fwww.pinterest.com%2FAlliekat1008%2Ffish%2F&docid=Lgrp0K69bWQFAM&tbnid=jhKYwWMQr1fblM%3A&vet=1&w=620&h=620&bih=708&biw=1517&q=clownfish%20cute&ved=0ahUKEwiniLDVg8zSAhVKfrwKHT91BMgQMwhzKE0wTQ&iact=mrc&uact=8#h=620&imgrc=jhKYwWMQr1fblM:&vet=1&w=620
