Dwarf cushion star

[2balive]

I collected 3 small cushion stars about 6 months ago (ended up having 4, not sure where the other one came from). They are thriving in my tank and are now large (about 1.5cm across) and thick with stunning colors.

I am however baffled by the lack of information on then online in terms of keeping them in a reef tank?

The only reference I could really find on them has been in the Two Ocean guide .

From the guide I deduced that the once I have is Patiriella exigua and not P. dyscrita based on having collected them from rockpools. How would one make a positive identification?

My ones also looks like they filter feed as there is "polyps" on their top side (see pic) and they often like sitting in high flow areas. According to the book they are algae film feeders (only)?

Does anyone else keep them and have more information on them?

If it is P. exigua, they are egglayers without an plantonic stage, it would be interesting to see if they can reproduce in a reef tank. Has anyone had success with them?

[459b]

A few guys keep them. They great at keeping nuisance algae under control. I've seen them spawn in captivity. Not something you want to happen, as the thousands of t y offspring mamge to get themselves into every corner of every pump/chamber/pipe/etc

[2balive]

Never thought of that, hope I can spot the eggs when it happens and remove before then.

Any view on being a filter feeder?

[459b]

There is a thread somewhere on MASA with a pic of the eggs. It's not common that they spawn so I wouldn't be too worried.
A billion Baby sea stars is nothing a pair of harlequin shrimp can't handle.

[Keanan]

I had a few of them, but they didnt last long as my temp was constantly high(I think that was the reason).
Well even if the eggs do hatch, thats the perfect excuse to get a pair of harlequin shrimps.

[2balive]

Running my tank between 26deg and 27deg, they seem happy, been in the tank now for nearly 6 months.

Interesting in the first month they use to climb out of the tank and sat above the water line for a few hours, stopped doing this at one point and now stay submerged.

Must be very little on the web on them, even @belindamotion is stumped?

[RiaanP]

I got some of them. They eat the algae film, that normally develops on the glass. Running out of that they can eat coralline algae.

If you want them, you should not clean one panel at least. Then there should be enough for them to eat. I do not clean my back glass at all. And they keep it clean enough.

They are not filter feeders.

If you collected them out of rock pools, then they do have the tendency to move to the top of the waterline in the beginning. But unlike snails they will not climb out. After a couple of months they realize there is no more tides and they stop doing it.

They can only take higher temperatures for short time periods. Rock pools exposed to the sun. Constant high tank temperatures speed up their life cycle and they do not last.

[Keanan]

Originally Posted by Len

Running my tank between 26deg and 27deg, they seem happy, been in the tank now for nearly 6 months.

Interesting in the first month they use to climb out of the tank and sat above the water line for a few hours, stopped doing this at one point and now stay submerged.

Must be very little on the web on them, even @belindamotion is stumped?

Had a problem where my temp was 29/30deg. Still have it now and then.

[belindamotion]

Originally Posted by Len

Must be very little on the web on them, even @belindamotion is stumped?

..sorry...didn't know about this Thread.....basically off line whole day...

• Patiriella aucklandensis
• Patiriella brevispina
• Patiriella calcar
• Patiriella exigua, now Parvulastra exigua
• Patiriella gunnii
• Patiriella medius
• Patiriella mortenseni
• Patiriella occidens
• Patiriella oriens
• Patiriella parvivipara
• Patiriella pseudoexigua
• Patiriella regularis
• Patiriella vivipara
• Patiriella fimbriata

http://en.wikipedia.org/wiki/Patiriella

The Echinoblog: A scientific mystery! Self-Fertilization in Parvulastra exigua
http://www.biolbull.org/content/210/2/158.full

A common resident of inshore rocky reefs along the Victorian coast is the Little Sea Star Parvulastra exigua. The species feeds on algae and detritus and grows to 20mm.

Underwater Australia Geelong - Queenscliff - Neville Coleman/Nigel Marsh : Neville Coleman

[2balive]

Hi

Not much body in the links, they seam to be a "little described" specie, specially in terms of reef tanks.

Mine are little starts (pun intended), eat tons of film algae, also a lot of coralline algae in my tank. Very gentle creatures, does not bulldoze anything like the urchins.

Still interested in mines "filter-feeding" habits.

[Broder]

Don't know how they would filter feed, as they have scraping type mouthparts? I used to collect them for my harlequin shrimp but they didn't survive for long, no more than about 6 months or so even if not eaten by it. They are pecked on by butterflys and centropyges, but I don't know why they don't survive long term, as all of their requirements seem to be catered for. Maybe they just have a short lifespan? I have had new ones grow, either from larval stage in water changes, or from spawning in the tank, but I can't be sure if they reached adulthood.

[2balive]

Know they are not suppose to be filter feeders, but if you look at the picture of the red one, you can see that it has hair like 'polyps' sticking out all over it's back.

Let's see how these do, had them for six months now and still going strong.