More Stars of Singapore

Brittle stars and feather stars are relatives of sea stars and are also found on many Singapore reefs and shores.
In this photo is a smaller black-and-white brittle star, nestled among the feathery arms of a much larger pale pink feather star. It appears this brittle star usually lives on a feather star!

Here's more about these amazing animals!

Like sea stars, brittle stars and feather stars are Echinoderms too (Phylum Echinodermata).

The sandy shores and seagrass areas of our Northern shores are sometimes literally crawling with these energetic little animals. The ones found on the sand are sometimes hard to spot as they match their sandy background well.A brittle star is almost all arms. Unlike their rather stiff-armed sea star cousins, brittle stars have long flexible and bristley arms that can writhe rapidly in a snaky manner. The arms are attached to a tiny central disk.

Although tiny brittle stars may look boring, a closer look reveals their wonderful patterns and colours! Like the sea star, the brittle star's mouth is on the underside.

Among the seagrasses and seaweeds you may spot speedy but beautiful small brittle stars.

The undersides of stones may sometimes be crowded with really tiny brittle stars.

Some brittle stars live inside sponges!

This commonly seen smooth brown sponge has lots of holes. Often, each hole is occupied by a tiny brittle star. When the sponge is submerged, and especially at night, you might see the brittle stars sticking out their tiny arms. This give the sponge a rather 'furry' look.

Large brittle stars with really long arms (15-20cm) may hide under coral rubble.

Often, all that can be seen of them are their skinny, spiny arms. These are sometimes mistaken for bristleworms.

Feathery stars

Like brittle stars, feather stars have thin, long and highly flexible arms. But while most brittle stars only have five arms, feather stars have an explosion of long feathery arms!

Juvenile feather stars start with five arms but repeatedly grow two arms in place of each arm branch that is shed. This branching happens near the centre. Thus feather stars may end up with 10 or more arms, in multiples of 5.

Unlike sea stars and brittle stars, the feather star is the only echinoderm with its mouth facing upwards. On the underside of the feather star there is a claw-like appendage that is used to grip the surface.

Feather stars are not so commonly encountered on the intertidal and usually found in deeper waters where they are seen by divers.

Feather stars are often seen perched on sea fans or corals.

The banded feather star on the orange sea fan was taken by Jani at Raffles Lighthouse, while the one on the white sea fan was taken by Debby at Pulau Hantu.

And Chay Hoon shared this lovely large pink one she saw diving at Kusu Island.
Basket Star!

No, we are not being rude and calling the star names. The Basket star is another echinoderm that is rarely seen. In fact, those of us who have been exploring Singapore's shores for years have seen it only once so far!
Like the other stars, the Basket star also has five arms emerging from a central disk. Each arm, however, divides into many curly branches! Isn't just an amazing animal?!
It was super spotter Chay Hoon who saw this marvellous animal on Sisters Island.

Please be gentle with our stars

As its name suggests, a brittle star has a tendency to fall apart. It may purposely throw off an arm when threatened. Feather stars too, may shed arms if they are frightened. So please don't stress these marvellous, delicate animals.

Didn't see any brittle stars?

Brittle stars are the most common echinoderms on our shores but rarely seen. Often small and shy, they tend to be more active at night. Be patient and look closely. And even if you do manage to spot one, these fast-moving animals often rapidly disappear into some hiding place. They are particularly sensitive to light and will curl up into their hiding places as soon as your torchlight falls on them. So taking photos of them are a real challenge!

Stay tuned for more

There are yet more fascinating relatives of these 'starry' animals. More about them in upcoming features.

Links to more
Lane, David J.W. and Didier Vandenspiegel. 2003. A Guide to Sea Stars and Other Echinoderms of Singapore. Singapore Science Centre. 187pp.
Photos of echinoderms of Singapore on budak's flickr

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