Slime Star!
Did you know about the species of sea star in our waters that releases slime to deter predators?
Slime stars are so wickedly adapted! Their distinctive puffy bodies have led to them also being known as Cushion Stars. 
They release a LOT of thick, transparent goo from their upper surface when disturbed.
Disturbance constitutes rough handling, temperature shock or when other sea star species try to eat them. Sunflower Stars and Morning Sun Stars are known to trigger the slime production and get a mouthful of goo. The mucus is reported to be toxic to other invertebrates if they are immersed in it for 24 hours.
How much mucus do Slime Stars produce?
See the Hakai Institute’s video below.
What is also so unique about Slime Stars is that they “exhale” water through that big pore in their upper surface every few minutes (the osculum). The full “exhalation” of the water takes about 5 seconds. You can see in the photos and video below how wide the hole opens. Water enters the sea star on the underside (through ambulacral grooves).
The tips of the arms / rays of Slime Stars are also distinctive. See how they curl upward? That is believed to be an adaptation to hold the mucus on the upper surface of the sea star.
As a result of genetic research, it has been put forward that the individuals with dark markings may be a distinct species from the solid-coloured ones. Currently, they are all classified as Pteraster tesselatus.
– Maximum size: 24 cm across.
– Known range: Bering Sea to Washington State; from 6 to 436 meters.
– Diet: Sponges, tunicates, and bivalves such as the False Jingle.
Sources:
- Invertebrates of the Salish Sea – Pteraster tesselatus
- Neil McDaniel – Sea Stars of the Pacific Northwest – Slime Star
- A Snail’s Odyssey – Sea stars – Defences – Mucus
My photos in this blog are all from near northeastern Vancouver Island in the Territory of the Kwakwa̱ka̱’wakw (the Kwak̕wala-speaking Peoples) ©Jackie Hildering.
The Marine Detective 
7 Responses to “Slime Star!”
Beautiful animals. Tha k you for the pics a info,
Really appreciate the feedback.
Wow! I thought slime with worms (the ” toy”) was the slimiest thing.
Thanks Jackie for another interesting glimpse of colourful, wonderous beings nature has shaped.
Always incredulous at what you bring to us. So appreciated. This was a great presentation of a beautiful creature.
Thank you.
Jane
Thank you so much for the comment and feedback that helps fuel these efforts.
They are very cute animals – interesting article, thanks!
Thank you so much for the feedback Violet.