18 February 2010

Awesome Ophiuroids: Brittle star talk at St. John's Island

We're off today to visit the Tropical Marine Science Institute at St. John's Island!
Organised by Jun (under the welcome sign) who lead a large and very enthusiastic group to the Institute.

We walk past some large and interesting trees such as this strangling fig, slowly murdering its host, a Tembusu tree.
We're here for the talk about brittle stars by Dr. Toshihiko Fujita of the National Museum of Nature and Science, Tokyo. He's here to review our brittle stars and is hosted by the Raffles Museum of Biodiversity Research and TMSI.
In the too-brief info-packed talk, I learnt more about brittle stars than I thought I could! He shared in a very easy-to-digest manner, the key aspects of the various beasts that make up the Ophiuroidea. These include the enigmatic basket stars.
Among the most sought after is this brittle star that is found on black corals.
It's tricky and fiddly to figure out the identity of brittle stars. We need to look at various tiny body parts. Brittle stars are so poorly studied that much is being discovered about how to classify them.
Dr. Fujita also shared some of his favourite ophiuroids. Among them, were 'arboreal' brittle stars. As the name suggests, they are 'tree-dwelling'. Instead of trees, these creatures climb up whip corals and other long skinny cnidarians. He showed this brittle star infested 'forest' in the deep sea, 1,200m deep!
His studies revealed that the brittle stars don't eat their 'climbing post' and probably use these to get to an ideal height above the sea bottom where they can gather food from the water. They have been seen to adopt various postures in their 'trees'. With their arms spread out in a wriggly kind of way, or elongated, or tightly wound around the 'tree branch'. These brittle stars were also found to have two kinds of arms: a pair of long, thick arms equipped with grapling hooks, while the other arms are shorter and thinner.
His other favourite kind of brittle stars are 'hitch-hikers'. Many, for example, hitch a ride on jellyfishes! We must take a closer look at jellyfishes!
Another fascinating kind of brittle stars are those that brood their young! Instead of releasing eggs and sperm like other brittle stars do, in some the eggs develop with the parent brittle star! See the cute little pair of white star-shaped animals? Those are the 'baby' brittle stars! Among some of the unanswered questions is how do those babies squeeze of out tiny slits in the parent?
Keeping the best for last, Dr. Fujita's most favourite brittle stars form dense beds, in the gazillions, on the deep DEEP sea bottom.
Found at a depth of 200-500m, these creatures can form a swathe 10km wide and 1,000km long. AWESOME!! As Dr. Fujita says, at 200m, brittle stars RULE!!
But the most incredible part was when he shared a video of this living carpet actually grabbing and eating fishes that get too near them! They also overwhelm small squids. While one single brittle star can't catch a fast moving animal, the prey is easily overwhelmed by the huge numbers of these many armed and no doubt very hungry creatures. The Echinoblog has a great post with photos of these sea stars catching a squid.

I certainly gained a new respect for these seemingly fragile creatures!

Dr Fujita also shared about the National Museum of Nature and Science, Tokyo. It has several locations, with botanical gardens and other interesting exhibits and huge collection!
Certainly worth making time to visit if we should be in Tokyo! There's more on their website which has virtual tours and other interesting information.

After the talk, Dr Serena Teo gave us a tour of the TMSI facilities.
The Institute has lots of amazing facilities for studying all kinds of marine issues. And here's Mei Lin's baby Giant clams! Hello!
Among the projects is an effort to understand how we can encourage marine life to settle on our sea walls. Here's a bunch of tiny little hard coral colonies.
Soft corals too! These grow much faster. They are all so small and cute. Unfortunately, being small makes them vulnerable to nibbly fish and big floating junk that squishes them. It's heartening to hear that much is being worked out to help marine life settle more quickly on our sea walls. Read more about the "Garden Cities in the Sea" project.
An interesting titbit that Dr Serena shared was about the wooden objects at the Institute. A Tembusu tree on the premises that had died was painstakingly sliced up and made into various useful and whimsical marine life pieces. How wonderful!
We spent a long time at the touch pool that has been created for the public outreach programme that TMSI is offering.
It is full of all kinds of colourful marine life!
Some of us whipped out our underwater cameras and took lots of close ups.
There were sea stars, sea cucumbers, a sea urchin, various hard and soft corals, zoanthids, corallimorphs, sea anemones, all kinds of seaweeds and even seagrasses (to show how they are different from seaweeds). More about the Public Outreach Programmes at TMSI and about what you can see at St. John's Island.

We used the Pasir Panjang Ferry Terminal which is right next to the massive project to extend the Pasir Panjang Container Terminal. There are huge structures there, with an ordinary workboat for scale.
And mountains of sand piled up for this enormous reclamation project.
This site is right next to Labrador Nature Reserve. Sigh. Let's hope the project will be completed soon and that the shores nearby can recover quickly.

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