I wasn't very lucky with my plan to dive Layang Layang, a small man-made island perched on an atoll in the South China Sea, earlier this year. Just a week before my long-awaited trip I was diagnosed with PVNS, a kind of tumor growing in the joint in my right knee. Immediately I had to undergo an arthroscopy or key-hole knee surgery. By the time we were supposed to fly to Layang Layang my right leg was totally immovable and I had to walk with the help of a crutch.

Broken hearted, but facing a choice of either recuperating in Singapore in the confinement of my tiny apartment or following the group and recuperating in a 'paradise', I decided to go anyway with the group. It wasn't as I had expected though. To tell a long story short – I was bored. Totally bored. An atoll in the middle of blue sea, away from the civilisation, is not a place for an invalid like me. It was heart breaking to see my boyfriend and friends went out each morning to do their dives, while I had to be happy sitting the whole day in the restaurant terrace, staring at the sea. I definitely wasn't happy. So this is a warning – if you're not a diver, don't go there. There's not much to do other than play in the swimming pool and sit in the sun. And eat. Well, it could be a dream holiday for some people but definitely not for me.

Anyway, I'll stop bitching and moaning and start talking of more useful things :)  Even though I didn't dive Layang-Layang at all, I can report this: Layang-Layang must have a healthy coral reef. And how do I know this? Well, my boyfriend brought my camera underwater everyday and he took photos of any fish he could snap at. On the surface I downloaded the photos, sorted them out and identified the fish. Surprisingly, of all the fish photos he took, we managed to identify 19 different butterflyfish species. That's impressive and since butterflyfish indicates healthy reef, the reef around Layang-Layang must be healthy.

I know that many divers, especially those already pocketed hundreds of dive hours, don't consider reef fish such as butterflyfish or anthias interesting. Most would give a cursory glance and register briefly – lots of reef fish. That's it. They would then hunt for the more exotic fish like ghost pipefish, frogfish, barracuda, stingray, shark and the like, and creatures like turtle, crab, shrimp and nudibranch. But my boyfriend has this fascination to fish, any fish. While other divers hunt for tiny nudibranch he'd be happy snapping away at the colourful reef fish. He would then diligently flipped his fish identification bibles and identify them. And actually his fascination kind of rubbed on me and now I do the same, we become aspiring fish geeks.

I remember my instructor Abi told me as a novice diver two years ago that butterflyfish can actually indicate the health of coral reefs. This site www.vifishandwildlife.com confirms that. It says that since butterflyfish mostly feed on coral polyps, the abundance of butterflyfish is in direct correlation with the distribution and amount of the corals. Also butterflyfish respond to declines in coral quality and abundance with behavioural and spatial changes. Therefore the condition of a coral reef can be monitored by observing its resident butterflyfish. I can't find any information on the web that connects the diversity of butterflyfish with the health of coral reef. I was hoping to be able to confirm that the more type and number of butterflyfish you find in a dive site, the better reef condition is. But maybe it's not like that. I suppose maybe the nooks and cranny of different islands with deep seas between them in the Pacific encouraged specification? Not sure, I'm not a biologist so before the real biologists out there boo-ed me I better stop talking.

Anyway, the number of species of butterflyfish in Layang Layang is quite impressive. We've never actually record the diversity of butterflyfish in the other dive sites we visited, but we can say that in Layang Layang we found more species that we have never seen before in other places. The above mentioned website, for example, also mentioned that only 7 species of butterflyfish can be found in the Caribbean, so 19 species is, as I said, quite impressive

Butterflyfish are small, thin, disk-shaped fish with pointed noses. Butterflyfish are fairly small, most are 12-22 centimetres in length although some species could grow to 30 cm. They're common and usually swim in shallow water, but they constantly dart from place to place and rarely stopping anywhere for long. They're mostly brightly coloured and patterned, hence the common name butterflyfish. Their Latin name Chaetodontidae, however, was derived from the Greek words chaite meaning "hair" and odontos meaning "tooth", which describe their rows of brush-like teeth in their small mouths.

Butterflyfish are bottom feeders. They feed primarily on polychaete worms, coral polyps, crustaceans and mollusk eggs, scraping the invertebrates with its bristly teeth. However some juveniles and adults often form plankton-feeding groups and clean other reef fishes such as parrotfishes and surgeon fishes. Butterflyfish are diurnal, active during the day and sleeping at night. At night they find shelter among the corals from night predators such as moray eels, sharks, and other large reef fishes.

Butterflyfish belongs to the Kingdom Animalia, Phylum Chordata, Subphylum Vertebrata, Class: Actinopterygii or Osteichthyes (Ray-Finned or Bony Fishes), Order Perciformes (Perch-Likes), Suborder Percoidei and Family: Chaetodontidae (Butterflyfishes).  Sources differ in the number of genera and species within this family. Some say there are 120 species and 10 genera, some say 127 species and 11 genera. Some common genera are Chaetodon, Forcipiger, Hemitaurichthys and Heniochus (Bannerfish).

The species we found during our dive trip in August 2006 are as follows:

Chaetodon adiergastos (Eyepatch Butterflyfish)

Chaetodon auriga (Threadfin Butterflyfish)

Chaetodon baronessa (Pacific Triangular Butterflyfish)

Chaetodon benneti (Eclipse Butterflyfish)

Chaetodon ephippium (Saddled Butterflyfish)

Chaetodon falcula (Saddleback Butterflyfish)

Chaetodon lineolatus (Lined Butterflyfish)

Chaetodon lunula (Raccoon Butterflyfish)

Chaetodon lunulatus (Pacific Pinstriped Butterflyfish)

Chaetodon melannotus (Black-backed / Tail-Spot Butterflyfish)

Chaetodon ornatissimus (Ornate Butterflyfish)

Chaetodon punctatofascitus (Spot-banded Butterflyfish)

Chaetodon rafflesi (Lattice Butterflyfish)

Chaetodon speculum (Oval Spot Butterflyfish)

Chaetodon trifascialis (Chevroned Butterflyfish)

Chaetodon unimaculatus (Teardrop Butterflyfish)

Forcipiger flavissimus (Long-nosed Butterflyfish)

Hemitaurichthys polylepis (Pyramid Butterflyfish)

Heniochus singularis (Singular Bannerfish)

The common names can be different from book to book, but the latin name should be the same. We used the following for our main source: "Reef Fish Identification – Tropical Pacific" by Gerald Allen, Roger Steene, Paul Humann and Ned Deloach; complementing it with this book: "Asia Pacific Reef Guide" by Helmut Debelius and some internet sites. If you're a fish buff and you found that we have made mistakes, please do inform us. We are just novices in the world of fishes and know almost zilch about marine biology, so the probability of us making the wrong identification is quite high. We're sorry some of the photos are blurred; it's not easy taking pictures of darting fish with a compact camera and no strobes. All these photos were taken by Martin D.

 More on Butterflyfish:

http://en.wikipedia.org/wiki/Butterflyfish

http://marinebio.org/species.asp?id=433

http://www.richard-seaman.com/Underwater/Australia/Cairns2003/Butterflyfish/Sampler/index.html

http://seafocus.com/species_butterflies.html

http://www.saltcorner.com/sections/zoo/butterflyfishes.htm

http://www.vifishandwildlife.com/Education/FactSheet/PDF_Docs/22Butterflyfish.pdf#search=%22butterflyfish%22