Field Trip 2: RWS Marine Life Park

(Note: All photos courtesy of Jenny and Rayhan. Information retrieved by Jenny, Chen Lin and Zack. Humor provided free of charge by Rayhan because nobody has a sense of humor. And blogger formatting is difficult.)

The air smelled of earth and rain as the class trooped to the sheltered world of the aquarium. Only the peaceful noise of rain showering the world reached our ears, and there seemed to be a crisp chill left over from the shadow of raindrops. We exited this strange world we call a rainy day, to another wondrous world: the Marine Life Park, where more of nature's weird and wonderful works await. (Rayhan's note: Zack sounds like a lit student but surprisingly he isn't)

When we first entered the aquarium we were greeted by a shipwreck on the ocean floor (not the Titanic though). I waved at the ship, and the ship said "Hello!" and waved back (Please ignore this weird attempt at satirizing literature). Around the ship lurked multiple zebra sharks, the first sharks of the day. Interestingly enough, the male zebra shark bites the tail of the female when laying on the ocean floor before they begin mating. Talk about an aggressive male.

More sharks (though unborn)! These shark embryos are encased inside eggs that function "like a ziploc bag", as our guide had delightfully informed us. This is because when the egg hatches the baby shark can just swim out of the shell. We could even see the baby shark thrashing about inside the egg. Spooky.




 
A huge coral garden! This is actually artificial coral, as the fish living in the tank are not “reef-safe”, meaning that they tend to scrape away the zooxanthellae living on the corals that keep them alive. These zooxanthellae are also the ones that give the corals colour, and require sunlight to photosynthesize. The zooxanthellae and the coral have a mutualistic relationship, as the coral provides the zooxanthellae with a place to safely photosynthesize as well as providing the compounds the zooxanthellae need for photosynthesis, and the zooxanthellae provides the coral with oxygen and glucose, also helping the coral get rid of waste products. Corals, after all, are animals, and not plants, contrary to popular belief (anyone who debates this, I dare you to find chlorophyll inside a coral cell). When the zooxanthellae is scraped off, the corals will become white and will die. If they are hard corals, they will leave behind a white hard skeleton. If they are soft corals, they simply dissolve, as they have no skeleton. This process is known as coral bleaching.

The mangrove habitat: Half freshwater, half saltwater. It contains mullet fish, archerfishes and mudskippers. The archerfishes can jump out of water and squirt a jet of water to hit its unsuspecting prey resting on a low branch of a nearby tree. The mudskippers, which were mostly mentioned in the previous blog entry, feed on krill, which are high in protein. There are also rays here, usually resting on the sandy floor.

We meet the bottlenose dolphins at their exhibition, arguably one of the star attractions at the aquarium. They are considered to be pretty intelligent. Dolphins have an organ in their head known as the melon to aid them in echolocation. Sometimes, they have red marks on their body; this is because dolphins use their teeth to bite one another, possibly to communicate. However, their skin sheds every 2-3 hours, so its unlikely these red marks are permanent. When the female dolphins give birth to their young, the tail usually emerges first since its the strongest part of the dolphin. 

Their whole body is designed for fast swimming, such as a streamlined shape, as well as this powerful tail. Their tail, unlike sharks, flap vertically. Sharks flap their tails sideways. Dolphins are also considered to be quite playful, and jump out of water at times. To differentiate between male and female dolphins, one simply has to look underneath the dolphin to look at the pattern of the slits there. If it is shaped like an exclamation mark, it is a male. Since there are more male dolphins than female dolphins in the exhibition, it is apparently common to see multiple male dolphins chasing one female dolphin. (Sorry for the low picture quality! Look for the dolphin on the left side of the picture, right above the last rocky outcrop)

The largest school of fish that we saw in the aquarium were the anchovies, also known as the delicious ikan bilis. They travel in schools for protection, reproduction, and energy saving purposes (but not protective enough to escape from fishermen!). Travelling in a school decreases the overall drag of the school of fish as compared to the drag induced by water on a single fish. Oh dear, even physics has invaded biology.

Giant spider crabs: scavengers, eat anything edible that comes along their way. Apparently, during WW1 and WW2, when bodies were dumped into oceans and such, some of these animals were responsible for scavenging on the dead bodies. Morbid but true. Of course, now its our turn to eat them :P In the same exhibition, there was an isopod, which the guide likened to an “underwater cockroach”. They are also crustaceans, and have a tough exoskeleton to protect themselves as well.

Octopi (or octopuses?) can change to different colours. Brown and red signify a normal octopus, but if a octopus turns white, it shows that it's stressed. If anyone remembers, such an octopus was used to predict World Cup winners. Rayhan can do that too though, maybe just not that accurately (Rayhan's note: Zack just doesn't see my awesome powers of prediction). After the female gives birth, she actually stays there to take care of the baby, and will probably starve. Suckers on its 8 limbs enable the octopus to travel and to catch prey, much like how a kraken engulfs whole ships. Not saying that the kraken is real (who knows?).

Sea jellies! There were 2 species of sea jellies that the guide mentioned in detail: the moon sea jelly and the Indonesian sea nettle. The moon sea jelly is non-poisonous, while the Indonesian sea nettle is poisonous; it has tentacles that look like thin wisps that are loaded with thousands of nematocysts that can be released to launch a paralysing toxin. Sea jellies may be known to most as jellyfishes, but apparently the name isn’t very befitting since sea jellies don’t look like fishes. Same goes for starfishes; they should be called sea stars. Anyway, a sea jelly normally consists of 2 parts: the bell and the oral tentacles. The bell is used for locomotion by pulsating, while the oral tentacles are, well, to push prey towards their mouth. They feed on the white bits floating in the tank. Similar to corals, they also have a symbiotic relationship with zooxanthellae, which provides the sea jellies with nutrition as well as their colour. Also, if you’re stung by a sea jelly, you should wash pee in the opposite direction of the sting. Apparently it works. Sea jellies also look like plastic bags in a vague sense, and sea turtles like to eat them. Do the math. Yup, that’s right, lots of sea turtles choke to death on plastic bags since they look like sea jellies. Tsk, humans these days. Either we reduce our dumping of garbage into the ocean, or we start putting up signs underwater to tell all marine organisms what’s food and what’s trash.

And now, we reach the magnificent open ocean habitat. A great expanse of blue waters, where some of nature’s greatest works reside, behind the great glass wall that separates complexity from complexity, being from being. One can only try to reach out from behind the glass, hoping to get a glimpse into the mysterious secret world of these silent lumbering creatures.

(Please congratulate Rayhan for making such an incredible shot. Not.)

……

I suppose I can’t resist the temptation to add a soliloquy into every entry.

Anyway, the open ocean habitat is home to over a hundred thousand marine organisms. It’s the (second) largest aquarium in the world. Its most notable species of marine animal is probably the manta ray. The manta ray has cephalic lobes that are used to trap food; they are filter feeders who eat plankton and krill. Shows how you can be a peaceful giant. It doesn’t even have a sting, unlike the stingray. Sometimes, small fish follow it to consume the excess food the manta ray doesn’t eat. This is a symbiotic relationship known as commensalism. Travelling like that also helps to reduce drag when moving in ocean waters. The manta rays found in the aquarium are all reef rays. In contrast, stingrays, which are also found in the same aquarium, have a barbed stinger on their tail which can be up to 35cm long. Ouch. The sting isn’t usually fatal, but the most famous death caused by stingray is probably Steve Irwin, otherwise known as “The Crocodile Hunter”. They feed on fish, unlike manta rays, and have their gills at the bottom. 

Another notable creature featured in the aquarium is the grouper. Its a pretty huge fish that uses bursts of speed to catch its prey. Its mouth and gills also form a very powerful suction system to draw in its prey. The guide described it as having “Angelina Jolie lips” (which seems like a very disturbing image). However, seeing as Angelina Jolie is an extremely successful actor, who knows how far this fish will go in its acting career. I bet Mrs Grouper can play a pretty good Evelyn Salt. But I digress.

There are a few methods of feeding the fish in this aquarium. One is surface feeding, which simply involves placing food at the surface of the aquarium for fishes to prey on. Another method would be target feeding, where divers bring food down to some of the fish that tend not to come up to the surface, such as the grouper mentioned earlier.

Next, we move on to the rocky shore habitat. In real life, this would be described as an intertidal zone. Fishes living here need to adapt quickly to high tide and low tide. In addition, the salinity of the water can change with the tides, so fishes will have to adapt to that as well. The fish in this exhibit though, is the bluespotted ribbontail stingray. It is a bottom-dwelling species that frequents coral reefs. The blue spots on this stingray can be described as “neon”; that’s how striking they are. This stingray is rather popular on display due to its striking beauty, although its not very suited for captivity.

The triggerfish has a trigger that can be used both for protection and to hold on to corals. These fish are known to be more intelligent than other species of fish as they have the ability to learn from experience. Only a few species of the triggerfish, such as the titan triggerfish, are actually poisonous.

The clownfish, well known for its role in a certain movie that I shall not name due to the overuse of the joke (hint: F______ N___), is sequentially hermaphroditic; it can change gender. For example, when there is a shortage of females in the school of fish, one of the males can change its gender to become a female in order to sustain the population of clownfish. It is also known to be immune to the neurotoxin of sea anemones. Not immune to barracudas though.

The next exhibit, which contains many cichlids is known as “Lake Malawi”; probably due to the fact that the real Lake Malawi is home to many cichlids as well. Interestingly, even though there are many fishes with different appearances in terms of colour and pattern, there is only 1 family of fish here: the cichlids, of course. These cichlids’ most notable feature is that they hide their young in their mouth when there is any danger in the vicinity. Sometimes, baby fishes not belonging to the cichlid will also swarm in for the protection. Cichlids also incubate their eggs in their mouth to protect them. When I put eggs into my mouth, I eat them.

After so many instances of artificial corals, we finally come across an exhibit with real corals. This exhibit is much brighter than the rest. This is because the zooxanthellae that live on the corals need all 7 spectrums of light to photosynthesize. However, as light refracts at the surface of water, some special light is needed to produce this result. In addition, the fish here are reef-safe.

The lionfish is venomous. The difference between venomous and poisonous is that venom is injected by spikes of the lionfish. In contrast, poison has to be ingested, such as in the instance of the pufferfish. It could be said that venom is a more aggressive way of defending itself, while poison is a more passive method. Either way, it's still painful.

The sea cucmber was also in the lionfish exhibit. if it wants to defend itself, it vomits out its internal organs. Its also pretty slimy to begin with. And to think we eat it. (Relevant joke: How do you find the difference between a cucumber and a sea cucumber? Ask it. If you drown, it's a sea cucumber).

Moray eels have 2 sets of jaws: one set of jaws is to capture food, while the other set is to chew on food. It stealthily darts out of crevices to capture its prey. It has a symbiotic relationship with, surprisingly, the red and white shrimp. The shrimps get food, while the moray eels get a free cleaning service.

The next exhibit houses 11 different species of sharks. This includes the whitetip shark, as well as the hammerhead shark. The whitetip shark has an elongated body structure such that it can squeeze through crevices and holes to extract hidden prey. Sharks are cartilaginous, and have no bones. They have an asymmetric tail, with a larger upper lobe of a tail. Scientists believe that the longer upper lobe will cut through the water first, giving the shark both forward and upward thrust. Sharks also do not attack humans naturally, contrary to the popular belief inspired by the blockbuster movie “Jaws”; instead, the most common occurrence is that when humans are on a surfboard, from a shark’s perspective below the human, the surfboard looks like a seal. Sharks are also the apex predators of the ocean, and they help to balance the ocean food chain in this sense. They also portray the image of a ruthless, tireless assassin; they don’t even sleep. This is actually since they undergo ram ventilation. They have to keep swimming in order to force water through their gills to take in oxygen. Some sharks, however, can undergo buccal pumping instead, which is to passively flow water over their gills. These sharks usually simply lie on the ocean floor. You can tell if a shark is a male or female by looking around their pectoral fins. Males have claspers there, which are used during reproduction, while females don’t. Otherwise, female sharks tend to be a bit bigger than male sharks. Sharks have 3 ways of reproducing: they can exhibit oviparity, viviparity, or ovoviviparity. Oviparity involves the female shark laying eggs in the open, usually among rocks, corals, or in crevices to increase their survival rate, and viviparity involves a reproduction method similar to mammals; giving birth to young alive. Ovoviviparity is the most common among sharks, and its a combination of the 2 methods above; the eggs are fertilised and hatched inside the female, where the female will later appear to “give birth to young alive”, when in truth the babies were already hatched from eggs.

-----EPILOGUE-----
After the whole tour, we split up to look at more exhibits. Rayhan and Zack went to snoop around while Jenny and Chen Lin were being the hardworking people that they are and religiously taking photographs. Strangely, whenever Rayhan and Zack were about to meet Jenny and Chen Lin, Rayhan would somehow spy an unnoticed set of staircase that he’d take. He calls these “shortcuts”. At least these staircases led somewhere instead of into the shark tank or something. Thus, many possible encounters between the groups were avoided because of Rayhan’s awesome scouting and observational skills. When interviewed, Rayhan stated that he took the shortcuts because “the other group was too slow.” (Rayhan's note: In my defense, they were taking too many photos).