7. Animals on the Reef

Coral reefs are rich in life (has many plants and animals). This means that there are many different animals and plants living and working together. These animals are also competing against each other for food, space, nutrients and sunlight. All these different animals have a very special job to do on the reef. Some may clean the reef; some may clean the seawater, read on (click on the animal’s name) to find out about some of the most interesting reef creatures (animals and plants)

Ratu Kali, The Coral Polyp

“Cola vina! My name is Ratu Kali and I am here to tell you how important I am to the whole reef system!(area) We corals are what build up these huge structures called reefs. Each coral is made up of a colony (group) of tiny animals called coral polyps living together. A coral polyp is related to a jellyfish and is see through! So what gives me my colour? I have a special relationship (connection) called symbiosis where I have tiny microscopic (tiny) algae called zooxanthellae living inside my skin. The zooxanthellae give me my brilliant (bright) colours. This algae transforms (changes) sunlight and uses the polyp’s waste to make sugars through photosynthesis (process of making food At night I have to use my tentacles (arms) to feed. Even though I look like a strong hard rock, I am in fact, a very delicate creature! I grow very slowly, up to 5mm a year! I can be easily scratched or broken by careless touching and standing. I also have a special mucus (gel cover) layer on my body like coconut oil; this helps to protect me from diseases, harmful UV sunrays, and will keep me from drying out at low tide. If I am injured, death is not instant, (sudden) however; slowly I will get sick and die within 3-5 months.”

Lusia, The Lobster

“Hello! My name is Lusia! I am here to tell you how we see at night. Animals, like myself, need to find our way underwater at night or when the water is not clear. We need to use our extremely sensitive antennae (eyes) to “see” in the dark. We lobsters live in holes on the reef during the day and roam (look) for food at night! Our antennae are equipped (covered) with special sensory hairs which help us sense very small objects, chemicals, and even movement of the water. Our antennae act as feelers, helping us sense movement in the water, locate our prey and keep out of danger. Think about what happens when you wake up in the middle of the night to use the bathroom. Your eyes are not quite adjusted to the darkness and you use your hands to feel your way around making sure you do not bump into any walls or trip on anything left out on the floor! Your hands act as your antennae.”

Orisi, The Octopus

“Bula! My name is Orisi! I am here to tell you how I trick my prey (enemies) by disappearing. We octopus are soft-bodied animals related to clams and squid. I have 8 arms that surround my head and mouth. My arms have special suction pads on them, which I use to find my prey. We are a very tasty item on the reef and have developed tricks to escape from hungry predators. In a dangerous situation, I can turn on my turbo power and use what is called “jet propulsion.” I do this by sucking in water and squirting it out rapidly from a jet-like siphon (pump) located close to my head. This propulsion pushes me backwards at a very high speed, allowing me to quickly escape my predator (run away from the enemy I also have a special sack that contains dark ink. When threatened I can squirt (give out) this ink out through my siphon leaving a dark cloud in the water. This allows me to escape and vanish while my predator is left confused in a cloud of darkness! I can also change my skin colour in an instant to match my surroundings which is another clever way to camouflage (hide) me from my predators (enemies”

Simi, The Sponge

“G’day! My name is Simi! I am here to tell you how I help to keep the seawater clean. We sponges come in many shapes, sizes, and colours. Even though we may not look like it, we are actually simple animals. I live on the sea bottom and can attach myself to something solid, like a reef, and end up staying in one spot my whole life. Since I cannot move around to find food, I have to sit and hope that something good to eat floats by in the water! I have millions of tiny holes called “ostia.” I am called a filter-feeder because I eat by sucking in water through my holes, filtering out all the little pieces of food, and squirting (pushing out) the filtered water out of my body through a large hole. I help keep the reef clean by returning cleaner water to the ocean and also providing oxygen to the ecosystem environment.”

Sera, The Sea Urchin

“Cola! I’m Sera, the Sea Urchin! I am here to tell you about how we help clean the reef. We sea urchins have prickly needles all over us. These needles make me look dangerous but I do not attack unless you step on me! Many of us have short, blunt spines; others have long, sharp spines with very sharp tips. These spines can easily break off beneath your skin, injecting a toxin (poison) which can cause severe pain. These spines also help me to move, capture food, hold on to the reef, and keep enemies away. My mouth is located on my underside and this is made of 5 teeth that all work together to scrape algae (sea weeds) off the sea floor. My many teeth look like a star and together they are called “Aristotle’s Lantern.” By grazing on algae, I give the chance for animals such as baby corals to establish themselves and grow.”

Kiti, The Crown of Thorns

“Hi! My name is Kiti. I am here to tell you about why corals are my favourite food! We sea stars (starfish) belong to the same family as sea urchins and sea cucumbers called echinoderms. We all have tiny rows of tube feet running along our bodies which have very small, but incredibly powerful suction cups (holes) on their tips. I use these suction cups to allow me to walk up steep walls and even hang upside down! This large number of tube feet gives me incredible strength. If one of my legs is chopped off, I can grow that same leg back! I eat by pushing my stomach out through my mouth and on to a coral. Normally when I am found in small numbers on a reef, I eat the fast growing corals to allow space and light for the slow-growing corals to grow up. However, when I am found in large numbers on a reef, this is called an “outbreak” and I eat all types of corals, even the slow growing ones. This is because I am in competition with the other crown of thorns and I can devastate (destroy) and kill a reef very quickly!”

Samu, The Sea Cucumber

“Bula! My name is Samu. I am here to tell you about how I clean the ocean floor! We sea cucumbers are very simple animals and move very slowly across the ocean floor. I am shaped like a cucumber but I come in all different sizes and colours. I play an important role in cleaning the ocean floor by sucking up sand and debris (dead plant and animals). Over the span of one a year, I can vacuum up to 100 kilograms of sand! You will see the clean sand I leave behind me as I move along the ocean floor. When I am attacked or touched, I will throw up all my sticky messy guts (stomach contents) and leave them behind. I do this hoping that my enemy will leave me alone and eat my guts instead! Luckily for me, I can grow back new guts in only about six weeks! I am considered a gourmet delicacy (favourite type of food) in other parts of the world and therefore collected to be eaten! But because we grow and mate so slowly populations of my sea cucumber buddies are rapidly decreasing, disturbing the balance in the ecosystem!”

Pita, The Parrotfish

“Hallo! My name is Pita, The Parrotfish! We are very colourful, have strong fused beak-like teeth, and large oval shaped scales. I am very important on the reefs because I feed on algae growing on coral which leaves room for baby corals to settle and grow! The bits of rock that go in my stomach are crushed in to sand with the algae to aid my digestion. This makes me one of the most important producers (makers) of sand on coral reefs. I can produce up to one tonne of sand in one year! As reef fish, I start off my life as a drab (plain) coloured girl but I will eventually switch my sex to a boy as I grow up! As a male, I protect and bully a large group of females to make sure they remain as only my girlfriends! At night when I sleep I produce a special mucus (sticky gel) sack like a sleeping bag. This makes me invisible to predators at night while I sleep!”

Taru, The Triton Trumpet Shell

“Bula vinaka! My name is Taru, The Triton Trumpet Shell! I am here to tell you about my favourite food and my job on the reef! We Tritons are very well known because of our beautiful and desirable shells. We are very easy to collect and all too often sold in the shell markets. I have a very important job on the reef! That job is to eat Kiti, the Crown of Thorns seastar! When there are more of me around there are less Crown of Thorns seastars on the reef. This means that the corals will be under less stress from predation (threat) by the Crown of Thorns and the reef will be healthier! If the reef dies because there are too many Crown of Thorns there will be less fish for you to eat because animals do not like to live on a dead reef! Unfortunately because a high price can be fetched for my shell, I am now hard to find. The best thing to do is to try and avoid collecting and selling me!”

Jone, The Giant Clam

“Hi! My name is Jone, The Giant Clam! There are 9 species (types) of us giant clams and mostly, we have very colourful mantles (inner part of the shell). Just like Ratu Kali, The Coral Polyp, I have Zooxanthellae (small animals) in my skin which gives me my bright colours. Thirty years ago, you could see my brothers and sisters all over the reef. But today, due to my tasty flesh, you will hardly see any of us! There is a legend that the King of Giant Clams grew to 140 centimetres and weighed over 330 kilograms! I feed by sucking in the water around me, and straining (filtering) out all the tasty morsels in the water. Therefore, my special job on the reef is to filter and clean the seawater. I also have a very interesting smell. This smell attracts baby corals to come and live close by. This means I add to the reef by attracting these famous reef building animals. It is important to have many of us giant clams on a reef. I am very easy to grow and culture on an underwater farm. This benefits everyone when I have babies they will be carried by the currents to make homes on other reefs!”


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