Asterina, Harlequin and LPS and SPS debate

PirateGirl60 · Sep 17, 2020

So my husband and I are having a debate ...we have the blue dime sized hitchhiker asterina and currently the population is large. My husband believes the asterina will only attack zoas ...I believe they will attack sps , cloves, and even acros...We have read articles stating they are fine . We have read articles that said they can decimate a coral... we have purchased two harlequins in the past 6 months and both have disappeared. What Could be eating it? We know they were acclimated fine... munching on chocolate chip star leg in their lair and the next they disappear never to be seen again. Our water parameters are fine. The layout of the tank does not lend itself to hand harvesting... it is built into a wall 1/2 way up..
In a 180 gallon tank
we do have two cleaner shrimp
Two emerald crabs
Some bumble bee crabs
Regular cleaner crew
No wrasses
One yellow tang
One clown
One damsel

1. Are the blue asterinas a real problem or not?
2. If so, who should we try to remove to get a harlequin shrimp That doesn’t get eaten? We would love to have a harlequin they are great fun to watch.
3. If not a harlequin shrimp, then what?

fishguy242 · Sep 17, 2020

hi ,i would have to lean to the damsel,poss yellow if they were tiny,not sure of anything else that will eat,any you can remove by hand will help ,use net to scoop off glass couple hours after lights out,would love to see pic of tank

Timfish · Sep 17, 2020

If your starfish are splitting, showing different sizes of legs from different splits, they are Aquilonastra not Astria species which sexually reproduce. Here's a guide to Aquilonastra spp. This all got started back in the late 90's when an article was published in FAMA where the overnight death of a ~6" coral colony was blamed on 6 starfish. Itseemed to me then quite a reach to blame teh overnight death on just 6 starfish. After a couple decades experinence with the it still strikes me as a mistaken causality. Aquilonastra feed off biofilms and algae

bevo5 · Sep 17, 2020

In a 180g filled with Rock I wouldn’t be surprised if the shrimp are somewhere in the rock work doing their thing. I had a harlequin I didn’t see for months. They can find a very small space to hide. Maybe red light flashlight at night?

as for the stars - I don’t personally believe they eat corals but thats Based on zero factual evidence.

CaptainCooke · Sep 17, 2020

I'm interested in this as well. Does anyone know for sure if the asterina actually eat corals? I have also heard both that they do and don't. Do they only eat some types of corals?

OP is it possible that the shrimp is just hiding? Or were you always able to find them and see them before? Are you sure they are dead? Are the starfish making a comeback?

Phycodurus · Sep 17, 2020

bevo5 said:
In a 180g filled with Rock I wouldn’t be surprised if the shrimp are somewhere in the rock work

this ... my pair of HQS often hid until they started getting hungry. they'd start wandering around the tank more & more. they're not really explorers IME.

CaptainCooke · Sep 17, 2020

But do the asterina actually eat corals? Do the shrimp even matter if the starfish isn't doing any damage?

Phycodurus · Sep 17, 2020

yes, they do apparently. it's been documented in other threads:

Trying to figure out if Asterina starfish are really eating my zoas and palys...

I decided to do this today, after deciding yesterday I was going to thin out their population. I have 1000s of asterina starfish in my main reef tank, and dozens to hundreds in my other tanks. In general I am a big fan of them as they are free cleanup crew. They definitely eat some algae, and I...

www.reef2reef.com

ca1ore · Sep 17, 2020

The problem is that every small star gets called 'asterina' in this hobby regardless of the species. Most are harmless members of the CUC, others may be more predatory. Also, correlation is not causation. Burgeoning population of asterina and a dead coral does not mean the former caused the latter. In 35 years in the hobby, I have never reliably linked a coral death to the little guys. A large population can be aesthetically unappealing certainly. Also may mean you're feeding the tank too much.

PirateGirl60 · Oct 11, 2020

Timfish said:
If your starfish are splitting, showing different sizes of legs from different splits, they are Aquilonastra not Astria species which sexually reproduce. Here's a guide to Aquilonastra spp. This all got started back in the late 90's when an article was published in FAMA where the overnight death of a ~6" coral colony was blamed on 6 starfish. Itseemed to me then quite a reach to blame teh overnight death on just 6 starfish. After a couple decades experinence with the it still strikes me as a mistaken causality. Aquilonastra feed off biofilms and algae

PirateGirl60 · Oct 11, 2020

We finally remembered to take a picture when we harvested current batch of starfish.I believe these are the aquilonstra variety picture i from Indonesia, but can you verify? Thank you in advance.

Rjukan · Oct 11, 2020

Timfish said:
If your starfish are splitting, showing different sizes of legs from different splits, they are Aquilonastra not Astria species which sexually reproduce. Here's a guide to Aquilonastra spp. This all got started back in the late 90's when an article was published in FAMA where the overnight death of a ~6" coral colony was blamed on 6 starfish. Itseemed to me then quite a reach to blame teh overnight death on just 6 starfish. After a couple decades experinence with the it still strikes me as a mistaken causality. Aquilonastra feed off biofilms and algae

Thank you for this, I didn't know about Aquilonastras, but that seems to be what I have too.

Timfish · Oct 12, 2020

PirateGirl60 said:
We finally remembered to take a picture when we harvested current batch of starfish.I believe these are the aquilonstra variety picture i from Indonesia, but can you verify? Thank you in advance.

Those are Aquilonastra, the various number of legs and the mismatched leg sizes are typical of fissiparous starfish.

Pistol Peet · Oct 12, 2020

They eat coralline algae Harlequin shrimp with definitely help to eradicate them I've never seen or heard of them actually eating your Coral I just purchased a bonded pair of harlequin shrimp for this exact reason because they were eating my Coral but because I like my coralline algae I know some don't but I do and I wanted to get rid of them

xxkenny90xx · Oct 13, 2020

These are coral eaters. This is not up for debate, it is fact. Just ask my zoas

CaptainCooke · Oct 14, 2020

xxkenny90xx said:
These are coral eaters. This is not up for debate, it is fact. Just ask my zoas

Soooo ... feeling like I'm getting mixed messages here. Those look like the ones in the previous photo with the funny leg/arms. Does anyone know for sure? Or know of a good way to distinguish between the two types other than the odd size arms? These ones look lighter in color.

ichthyogeek · Oct 14, 2020

CaptainCooke said:
Soooo ... feeling like I'm getting mixed messages here. Those look like the ones in the previous photo with the funny leg/arms. Does anyone know for sure? Or know of a good way to distinguish between the two types other than the odd size arms? These ones look lighter in color.

Notice how the ones in the picture from PirateGirl60 are incredibly dark. The ones that xxkenny90xx posted are white/off-white with blue speckling. The ones I have ( unsure if they eat coral, but my corals were fine) are pure white with no blue speckling. Part of the identification comes down to color as well.

The funny legs/arms is just due to how the starfish reproduce: fissiparous - inclined to undergo division into smaller groups. AKA, they like to split apart to reproduce.

Nemo&Friends · Jul 4, 2021

I do not have corals, but hundreds of white aquilonastra. they are mainly on the glass and seems to eat film algae. I have plenty of coralline algae so the stars do not seem to eat it. However I have too many and it is becoming ugly. I just bought 1 harlequin shrimp. I will see what happen.