More tricky echis

On Pulau Sekudu today, there were yet more sea urchins and other echinoderms that look similar but yet different.

There was a white sea urchin with very pink spine tips and yellow bands on its body. As well as really long tube feet! I put it next to the more commonly seen white sea urchin.The two sea urchins rapidly moved away in opposite directions!

I also took a closer look at the Pencil sea urchins that were found everywhere among the seaweeds.

There are not only differences in colours but also shape of spines, especially the small spines.Here's a closer look.Could it be that the bigger one is older? Or are they different species?

There were also LOTS of Biscuit sea stars of various sizes.Smaller ones tend to be seen on seaweeds, while bigger ones were found on coral rubble.

Here's one that looked like a biscuit sea star on the upperside, but didn't have the the typical biscuit sea star pattern on the underside.

On the upperside, both looked somewhat similar.
Even with a closer look at the upperside.On the underside, the Biscuit sea star typically has the bluish markings along the grooves under the arms, and a yellow patch in the centre.But the star in the photo on the right didn't have this typical pattern.Hmmm...Anyone has any ideas about this?

There's still much to learn and find out about our marine life!