Reefs at our schools!

The IYOR roving exhibition is roving!

Here's where they'll be at:

21 Apr-24 May: at CHIJ St Joseph Convent

23 Apr-9 May: at Keming Primary School

5 June: at Dairy at Farm Adventure Centre

More about the roving reef exhibition.

If you'd like to feature the IYOR roving exhibition at your school, community or event, do drop us an email at

Sex, sea turtle, seagrasses and super star!

So much has happened during the recent low spring tide, it's hard to decide where to start.

But certainly the highlight must be the annual spawning by our hard corals!

Many waited with bated breath as the time of the year approached for mass spawning on our reefs. So it was with relief and delight that we finally hear that they Did It again this year.

Shared on the blooooooooooo blog, our corals were spawning at Raffles Lighthouse!
She also shares that coral spawning in Singapore was first recorded by Dr James Guest of Tropical Marine Science Institute, NUS in 2002. And that least 18 different coral species from ten genera and five families (Acroporidae, Faviidae, Merulinidae, Oculinidae and Pectiniidae) have been observed to spawn in our waters!

During that dive, a nurse shark was also observed and shared on the urban forest blog.

Alas, the volunteers at Hantu did not see mass spawning among the corals at Pulau Hantu during the Earth Day Coral Spawning dive on 24 Apr.

But they sighted Betsy - the ginormous resident hawksbill turtle at Hantu!

Other sightings included lots of colourful nudibranchs and flatworms, a sea horse, acropora goby, razor fish, a pregnant pipefish.

Blog entries about this trip
The Hantu Bloggers were back in the waters to explore Hantu on 27 Apr and spotted more nudibranchs, sea stars, feather stars, a GIANT cowrie, sting ray, sea horse and had encounters with jellyfish.
Blog entries about this trip
Meanwhile, a bunch of intrepid volunteers spent the low tide hunting for echinoderms with Dr Lane, co-author of A Guide to Sea Stars and Other Echinoderms of Singapore.

They spent Earth Day 22 Apr on Pulau Semakau. While they didn't find too many echinoderms, they did spot lots of other marine life including cuttlefish, and a really huge nudibranch.And Sam remarks: "Good Lord! Some moronic fisherman left his brain behind!"
He later explains: "Actually it's a brain coral (Family Mussidae)"

Blog entries about this trip
The echinoderm hunters had much better luck on Cyrene Reef on 25 Apr. This submerged reef in the middle of our port was simply teeming with sea stars and other echinoderms! This montage of Knobbly sea stars from the nature scouter blog shows the stunning variety in just one kind of sea star.
Although lots of echinoderms were spotted, it was only in the dying minutes of the low tide that Vyna found the sought after Special Star!
This beautiful jewelled sea star is a new record for Singapore! It is Pentaceraster sp., possibly Pentaceraster tuberculatus. It's amazing that a reef in the middle of our port can be rich not only in ordinary but also extraordinary marine life.

Other sightings include a fabulous red feather star, a flag-bearing fish, octopus, sea hares and more.

Blog entries about this trip
Meanwhile, the volunteers of TeamSeagrass were busy too!

A small team of Seagrassers set up and manned a booth about seagrasses at Singapore Polytechnic's Earth Day event on 22 Apr.With specimens including an unfortunate baby dugong (which has been dubbed Bruce), the volunteers share about the importance and plight of seagrasses.

TeamSeagrass also monitored the seagrasses of Sentosa's natural shores on 24 Apr.

In addition, there were lots of other activities ...

There were walks
There were talks
And there was training
  • ReefAlert Training was conducted, more on the ashira blog.
There's lots to discover about our shores! And much work to be done for them!

Here's more about what you can do for our reefs and shores.

Sea turtle sighted at Pulau Hantu!

The Hantu Bloggers encounter Betsy during a night dive to our very own wild reefs!

Although not much sign of spawning, the intrepid divers encounter lots of other marine life!

Visit the hantu blog for a video clip of Betsy and the colourful clouds blog and hbing's blog for more sightings during the hantu coral spawning dive.

Earth Day Dive at Pulau Hantu for Coral Spawning!

This year’s mass coral spawning in Singapore is estimated to fall over the next few days, from 23 - 25 April, 2008. As this period falls over Earth Day week, the Hantu Bloggers are making this dive a part of the their Earth Day 2008 activities!

Volunteer as a diver in this effort and help collect data that will be collated with surveys being done in other areas of Singapore, and will help scientists in understanding the factors that influence coral reproduction in Singapore and the nearby regions.

More details on the hantu blog.

Naked slugs of Singapore

A delight for shore explorers, these naked slugs or nudibranchs may be encountered on many of our shores. On coral rubble and rocky shores with sponges and other encrusting animals, as well reefs and even seagrasses.

What is so fascinating about these colourful slugs?

What are nudibranchs?

Nudibranchs are relatives of snails and clams but lack shells as adults. Indeed, 'nudibranch' (pronounced 'noo-dee-brank' to rhyme with 'bank') means 'naked gills'.

Some nudibranchs breathe with a flower-like feathery external gill on their backs. These elegant black-edged nudibranchs (Glossodoris atromarginata) have black-edged feathery gills which are constantly rotating in the water.
This is behaviour is believed to help improve respiration.

Other nudibranchs lack this feathery gill and their gills are hidden between the body mantle and the foot. The gills of this burrowing nudibranch (Armina semperi) is hidden in the folds on the body sides.
This arrangement probably better suits such a burrowing nudibranch, than a feathery gill on the back.

If they are naked, how do they protect themselves?

To protect themselves, some nudibranchs produce distasteful substances, toxins and even acids. They advertise this with bright warning colours.

These tiny nudibranchs with bright colours are probably not very tasty for predators to eat.
See the colourful feathery gills on their backs!

When the Black phyllid nudibranch (Phyllidiella nigra) feels threatened, it secretes a milky substance (see closeup in photo at right).
The Pustolose phyllid nudibranch (Phyllidiella pustolosa) may have blue or pink nodules.They too may release a milky substance when they feel threatened.

Other phyllid nudibranchs are sometimes seen too. Like the gaudy Varicose phyllid nudibranch (Phyllidiella varicosa) at bottom left.
And the amazing Eyed phyllid nudibranch (Phyllidia ocellata) on the right.

The Ceratosoma nudibranch (Ceratosoma sp.) has lobes on its hard body that are armed with glands secreting distasteful substances to discourage predators.
These nudibranchs absorb the toxic chemicals in their sponge food and incorporate these chemicals into their mantle glands.

Hidden in plain sight

Other nudibranchs are camouflaged to match their surroundings.

This large mottled brown nudibranch (Discodoris boholensis) is actually quite commonly encountered, but requires an experienced eye to spot as they blend well among the coral rubble.
This very large, rather fugly nudibranch (Ategema spongiosa) is easily overlooked as just another lump of coral rubble or scummy bit of rock.
Those that eat colourful creatures such as sponges or corals, may themselves be colourful to match their prey.

This bright red or rose nudibranch (Dendrodoris fumata) is actually quite hard to spot among the blobs of colourful ascidians and sponges growing on a rock.
Many are quite small and flat, so they can also easily hide in narrow places, like these really tiny nudibranchs.Stored stolen stingers: Aeolid nudibranchs have long, slender bodies with clusters or rows of elongated finger-like portions called cerata. Some nudibranchs, like Cerberilla nudibranch (Cerberilla sp.) protect themselves with the stingers of the sea anemones or corals that they eat.
These stingers are passed, undischarged, to the cerata. The cerata of these nudibranchs have special sacs at their tips that contain the stinging cells of their prey. Here, the stingers remain 'live', ready to fire off and protect the nudibranch.

What do they eat?

Most nudibranchs are carnivores, each species usually specialises in a particular victim. Being small and slow, they feed on immobile creatures like barnacles, sponges, ascidians, hard corals, soft corals, sea anemones, zoanthids, peacock anemones, sea pens and eggs of other creatures including other nudibranch eggs.

The commonly seen Jorunna nudibranch (Jorunna funebris) is believed to eat blue sponges.Indeed, these nudibranchs have been seen with their egg masses next to chewed up blue sponges.This large bobbled nudibranch with bright blue spots (Dendrodoris denisoni) also eats sponges, possibly sponges that live in murky, mucky sites.
It lacks jaws and a rasping tongue so it can't chew its food sponge. Instead, it secretes digestive juices onto the sponge and then sucks up the softened sponge!

These nudibranchs in pajamas (Armina sp.) are suspected to eat sea pens. They are burrowing nudibranchs and often seen near half chewed up sea pencils (the white stick like object in the photo).

The colourful Cuthona nudibranch (Cuthona sibogae) eats hydroids, a kind of immobile colonial animal that looks like an orange bush.While these rather cartoon-like Gymnodoris nudibranchs (Gymnodoris sp.) eat OTHER nudibranchs!There's photos and stories of a Gymnodoris eating another nudibranch on the colourful clouds blog taken during a recent dive at Pulau Hantu!

One of the MOST AMAZING nudibranch predators must surely be the marvellous Melibe!This large nudibranch has an expandable hood at the front with which it captures tiny crustaceans! WOW! More about this beast on the wildfilms blog.

Making more nudibranchs

When we see many nudibranchs gathered together, this may be because they are congregating on some food,or some hanky-panky is about to take place. This pretty nudibranch (Chromodoris lineolata) is commonly seen, but seldom in such large groups as in the photo on the right.

Nudibranchs are simultaneous hermaphrodites, that is, each animal has both male and female reproductive organs at the same time. They practice internal fertilisation. So each nudibranch has a complex system of tubes to avoid self fertilisation, to introduce sperm while at the same time receiving sperm from a partner, and for laying eggs.

Nudibranchs mate in pairs, lining up side-by-side, facing opposite directions in order to exchange sperm.Then they go their separate ways and each lays its egg mass, usually on the prey that they eat or on a hard surface nearby.

The egg mass often looks like a frilly spiral of ruffles.In most, the eggs hatch into free-swimming larvae which have shells.

Often, the larvae only undergoes metamorphosis and settles down when it is near its particular prey. The juveniles lose their shells and eventually turn into adult nudibranchs.

Nudis and us: Nudibranchs don't do well in captivity due to their specialised diets and are thus not extensively collected for the aquarium trade. Moreover, some nudibranchs such as the phyllids produce toxins that may kill their tank mates. However, they are part of the attraction for divers and other visitors to natural habitats.

Status and threats: None of our nudibranchs are listed among the endangered animals of Singapore. However, like other creatures of the intertidal zone, they are affected by human activities such as reclamation and pollution. Trampling by careless visitors and over-collection can also have an impact on local populations.

Links to more
photos of nudibranchs seen on Singapore shores on wildsingapore flickr

Earth Day and Singapore's reefs and shores

Although it is called Planet Earth, it is mostly ocean!

And to celebrate Earth Day, what reef and shore activities are in store for us in Singapore?

Find out whether there are coral reefs in Singapore, join the free mangrove tour at Pasir Ris Park, get Naked on the Chek Jawa boardwalk with the Naked Hermit Crabs, or dive Pulau Hantu our own wild reefs with the Hantu Bloggers!

22 Apr (Tue): "Are there Coral Reefs in Singapore?"

To celebrate Earth Day and World Biodiversity Day this year, NParks Conservation Division is organising a four-week Biodiversity Talk Series. To start off this series will be Mr Jeffrey Low (Senior Biodiversity Officer, NParks) sharing with us the vibrant coral reef biodiversity of Singapore! He will share with us the splendor of Singapore’s coral reefs through an array of beautiful photos. Come join him in the exploration of our local coral reefs in the comfort of your chair.

All are welcomed!

Time: 11am–12pm
Venue: Function Hall, Botany Centre (Singapore Botanic Gardens)
Contact: Wei Ling LIM

26 Apr (Sat): "Southern Haunt" talk at the Botanic Gardens

To celebrate Earth Day and World Biodiversity Day this year, NParks Conservation Division is organising a four-week Biodiversity Talk Series.

Ms Debby Ng of the Hantu Bloggers gives this second talk in the series. She shares about Pulau Hantu, one of Singapore's most renowned Southern Islands. Despite its prominence, it is constantly left to cope with a relentlessly changing coastline and marine environment. For a long time, the threats to Pulau Hantu have avoided the scrutiny of the public and the brilliance of its marine habitat gone unheralded. Debby Ng will bring clarity to the usually murky waters of Pulau Hantu with her underwater photos and videos.

All are welcomed!

More about Debby and her talk on the hantu blog.

Time: 2-3pm
Venue: Botany Centre, Singapore Botanic Gardens
Contact: Wei Ling LIM

26 Apr (Sat): Passage to Understanding Nature

A guided tour at Pasir Ris Park Mangrove. This precious pocket of mangrove was preserved when Pasir Ris Park was created. And with the current global issues such as conservation and pollution in mind, what better way to know about our green heritage and its importance through our guided walk along our newly constructed boardwalk!

Free guided walks given only for Earth Day.

To register pls call Wei Teng at 64653305 or Registration closes one day before the walk date.
Time: 9am
Venue: Pasir Ris Park Mangrove

27 Apr (Sun): Free Chek Jawa Boardwalk tour

The Naked Hermit Crabs introduce you to Chek Jawa without getting your feet wet.

It is Earth Day on 22nd April and the Naked Hermit Crabs urge you to forget about going shopping again in Orchard Road but come and spend a lovely afternoon at Pulau Ubin. Ditch materialism! Don’t let consumerism take over our lives! Spend some time with nature and see how Mother Earth can move your hearts.

Read more about what visitors have said about the walk on the adventures with the naked hermit crabs blog

Time: 3 pm meet at the Chek Jawa Info Kiosk
Duration: Two hours
Cost: no charge for now, but donations accepted.

27 Apr (Sun): Dive Pulau Hantu with the Hantu Bloggers

A unique and educational dive experience in our local waters. Discover what is truly, uniquely Singapore! Your support helps us monitor and document Hantu's reef on a regular basis! Let's see what's waiting for us out there this time!

Pre-registration is required.

Organised by the Hantu Bloggers, check out the hantu blog for more details of the trip and past exciting encounters.

Join the The Hantu Bloggers Yahoo Group to read the trip itinerary, and to be informed of future dives.


More wild happenings on the wildsingapore happenings blog.

Roving Reef Exhibition debuts at Adex

These special panels to celebrate Singapore's own reefs made their debut at the Asian Dive Expo. They were created by Underwater World Singapore.

They are now ready to bring the reefs anywhere in Singapore!

If you'd like to have these panels at your school, community or workplace, simply contact us at

Among the issues highlighted in the panels are:

Singapore has reefs!And here are some of them...Including one of our favourites, Cyrene Reef!Why are reefs important?Here's a closer look...Find out more about the threats to our reefs...a closer look...And what you CAN do to make a difference for them...a closer look ...These are also listed on this blog.

There are also some details about IYORIf you'd like to have these panels at your school, community or workplace, simply contact us at

Other blog entries about outreach activities during ADEX