Guess that sea star!

[lulubap]

So, a bit of a story here;

once upon a time my former coworker ordered a "magnificent biscuit sea star" from somewhere in West Africa. It was supposed to look like this:

Beautiful guy!
However, he came like this:

So my coworker was disappointed, to say the least. Though, this sea star turned out to be extremely hardy (knock on wood) and thrived in our invert system. He lived off of biofilm and seaweed. Eventually, I took a liking to him and brought him home. I was worried that my lack of biofilm would harm him but (knock on wood x2) he's been doing his best with his designated seaweed frag plug I drop in for him whenever he finishes eating the previous one.

I never really gave it much thought, but I was wondering if anyone on here could identify him? It's possible he may just be a low-quality grey biscuit sea star, but my other coworker and I think he's some sort of cushion star. Would greatly appreciate it, as I could also get to know more about his diet and cater to his needs better.

 

[ISpeakForTheSeas]

I think you're right - I think that's a Culcita sp. cushion star, most likely C. novaeguineae. If I'm correct with the ID, there's some good news and some bad news.

The good news is, they are super cool stars: they are surprisingly flexible despite their cushion shape, and harlequin shrimp don't seem to be interested in eating these guys at all.*

The bad news is that they are confirmed corallivores, eating corals like Acropora, Pocillopora, Monopora, and Pavona for certain (it confirmedly doesn't like Porites). C. schmideliana is also known to eat Galaxea, Goniopora, and Xenia, so I wouldn't be surprised to find if the star eats most corals. They also are known to eat some small inverts, such as urchins...

This was my cushion star that I had while while I lived in Hawaii. I used to feed him by placing him on top of clams on the half shell. That didn't stop him from eating 2 or 3 urchins.
View attachment 2608962

I haven't heard any complaints about them with snails or shrimp yet, but that doesn't mean they're entirely safe (though these guys are known to have symbiotic relationships with a shrimp species - Zenopontonia soror - a fish - Carapus mourlani - and a polychaete worm - Gastrolepidia clavigera - so they might not be too hard on inverts).

*The study that offered these guys to harlequin shrimp:

https://www.researchgate.net/publication/318718169_Sand_star_Astropecten_indicus_Doderlein_1888_as_an_alternative_live_diet_for_captive_harlequin_shrimp_Hymenocera_picta_Dana_1852

 

[AydenLincoln]

The first one is the same species as mine and is a West African Biscuit/Goniaster Tessellatus the second one you have is a pillow cushion starfish…most if not all of these species are not considered reef safe. These two species are not related or close to each other than being sea stars. I agree with it possibly being a culcita novaeguineae a large predatory sea star getting up to 12 inches. I should also mention names like biscuit and pillow sea stars are not scientific names and often stars are misidentified and nicknamed in this hobby because it’s easier for sellers and some people don’t know what they are truly selling.

 

[ISpeakForTheSeas]

Though, this sea star turned out to be extremely hardy (knock on wood) and thrived in our invert system. He lived off of biofilm and seaweed. Eventually, I took a liking to him and brought him home. I was worried that my lack of biofilm would harm him but (knock on wood x2) he's been doing his best with his designated seaweed frag plug I drop in for him whenever he finishes eating the previous one.

Sorry, I've been bouncing on and off a lot today and somehow missed this part earlier - how long have you had this star for?

I know they're said to eat biofilms (particularly those found on algae and sea grass, similar to the Chocolate Chip Starfish), but I haven't looked into that aspect much (most scientific reports like to focus on the coral eating). So, I'm hoping to hear you've been having long term success with it.

 

[lulubap]

I think you're right - I think that's a Culcita sp. cushion star, most likely C. novaeguineae. If I'm correct with the ID, there's some good news and some bad news.

The good news is, they are super cool stars: they are surprisingly flexible despite their cushion shape, and harlequin shrimp don't seem to be interested in eating these guys at all.*

The bad news is that they are confirmed corallivores, eating corals like Acropora, Pocillopora, Monopora, and Pavona for certain (it confirmedly doesn't like Porites). C. schmideliana is also known to eat Galaxea, Goniopora, and Xenia, so I wouldn't be surprised to find if the star eats most corals. They also are known to eat some small inverts, such as urchins...

I haven't heard any complaints about them with snails or shrimp yet, but that doesn't mean they're entirely safe (though these guys are known to have symbiotic relationships with a shrimp species - Zenopontonia soror - a fish - Carapus mourlani - and a polychaete worm - Gastrolepidia clavigera - so they might not be too hard on inverts).

*The study that offered these guys to harlequin shrimp:

https://www.researchgate.net/publication/318718169_Sand_star_Astropecten_indicus_Doderlein_1888_as_an_alternative_live_diet_for_captive_harlequin_shrimp_Hymenocera_picta_Dana_1852

1. thank you so much for the reply! i didnt expect to get an ID : )

caught him eating a dying snail as i was writing the initial post, eek. i'm not looking to do any SPS corals in my system, and he hasn't touched my soft corals at all! since it's a 15 gallon my tank i'm limited on inverts to begin with, so with this ID i know to be careful with my future stocking.

 

[lulubap]

The first one is the same species as mine and is a West African Biscuit/Goniaster Tessellatus the second one you have is a pillow cushion starfish…most if not all of these species are not considered reef safe. These two species are not related or close to each other than being sea stars. I agree with it possibly being a culcita novaeguineae a large predatory sea star getting up to 12 inches. I should also mention names like biscuit and pillow sea stars are not scientific names and often stars are misidentified and nicknamed in this hobby because it’s easier for sellers and some people don’t know what they are truly selling.

this is very surprising to me as he hasn't touched the numerous frags in my system ! thank you for the pointer regarding biscuit and pillow sea stars. always good to learn something

 

[lulubap]

Sorry, I've been bouncing on and off a lot today and somehow missed this part earlier - how long have you had this star for?

I know they're said to eat biofilms (particularly those found on algae and sea grass, similar to the Chocolate Chip Starfish), but I haven't looked into that aspect much (most scientific reports like to focus on the coral eating). So, I'm hoping to hear you've been having long term success with it.

I've had him ever since my tank finished cycling...nearing two months. he's been at our workplace for much longer than that. it's interesting to read about his corallivore diet, as the system he was in had no coral at any point

 

[ISpeakForTheSeas]

I've had him ever since my tank finished cycling...nearing two months. he's been at our workplace for much longer than that. it's interesting to read about his corallivore diet, as the system he was in had no coral at any point

Interesting - how long was it at your workplace?

 

[lulubap]

Interesting - how long was it at your workplace?

oof... longer than i worked there! and i started working there at around August. so he's been in captivity for over 6 months now

 

[lulubap]

Interesting - how long was it at your workplace?

i didn't realize how interesting of a case this was. if possible, i can keep updates on him. we affectionately call him "blob" but it seems he has more malice than he lets on...

 

[ISpeakForTheSeas]

oof... longer than i worked there! and i started working there at around August. so he's been in captivity for over 6 months now

i didn't realize how interesting of a case this was. if possible, i can keep updates on him. we affectionately call him "blob" but it seems he has more malice than he lets on...

I'd love to know how it does over the next few months, as most starfish I've heard of people keeping tend to die sometime around 6-13 months or so (but most of these are strictly biofilm eaters). I haven't gone looking too hard, but I only know of a few people who have kept cushion stars, so I would love to see how it does for you.

 

[lulubap]

I'd love to know how it does over the next few months, as most starfish I've heard of people keeping tend to die sometime around 6-13 months or so (but most of these are strictly biofilm eaters). I haven't gone looking too hard, but I only know of a few people who have kept cushion stars, so I would love to see how it does for you.

assuming that although he's been living off of seaweed for the past 6 months, he looks to resemble a species that is a corallivore, so what could I add to his diet? some sps i will definitely prioritize getting into his diet..would a clam on a halfshell work? I could have sworn i saw him eating a dying nassarius snail before i took some pictures to show this thread

 

[ISpeakForTheSeas]

assuming that although he's been living off of seaweed for the past 6 months, he looks to resemble a species that is a corallivore, so what could I add to his diet? some sps i will definitely prioritize getting into his diet..would a clam on a halfshell work? I could have sworn i saw him eating a dying nassarius snail before i took some pictures to show this thread

You can always try offering things like clams, and the star may or may not take them. The issue with sea stars is that it's hard to tell what they actually get nutrition from. So, for example, even if the star eats the offering of clams, that doesn't mean it's actually benefitting from eating those clams - it could starve to death from improper nutrition while having a stomach full of clams. Same with any snails, urchins, etc. that it may eat.

So, with that in mind, I'd personally pick up some really "invasive/weedy" Pocillopora (some people compare it to Xenia and Green Star Polyps) and offer it to the star - if it is C. novaeguineae, it should take it pretty readily (though they are known to primarily hunt at night). If it does take it, I would grow out a bunch of the stuff to feed the star.

 

[lulubap]

You can always try offering things like clams, and the star may or may not take them. The issue with sea stars is that it's hard to tell what they actually get nutrition from. So, for example, even if the star eats the offering of clams, that doesn't mean it's actually benefitting from eating those clams - it could starve to death from improper nutrition while having a stomach full of clams. Same with any snails, urchins, etc. that it may eat.

So, with that in mind, I'd personally pick up some really "invasive/weedy" Pocillopora (some people compare it to Xenia and Green Star Polyps) and offer it to the star - if it is C. novaeguineae, it should take it pretty readily (though they are known to primarily hunt at night). If it does take it, I would grow out a bunch of the stuff to feed the star.

duly noted. i’ll see if i can find some pocillopora locally. since it’s “invasive” i hope i’ll have some luck growing it.

sea stars are finicky creatures.

 

[ISpeakForTheSeas]

duly noted. i’ll see if i can find some pocillopora locally. since it’s “invasive” i hope i’ll have some luck growing it.

sea stars are finicky creatures.

Supposedly the green Pocillopora damicornis is the really invasive one (doing a bit more reading on it, it seems that it grows fast, and then occasionally its shaded polyps bail out and land in various different places around the tank, growing into their own colonies). The link below has an example or two (there are plenty more links if you look around a bit):

Pocillopora gone rogue

A few days ago, I had a pocillopora frag (yes it has totally encrusted that frag plug and is even growing on the underside of the frag rack) make contact with a monti cap on the same frag rack and it pretty much melted the monti where it made contact. I moved the monti but the poci has been...

www.reef2reef.com

 

[lulubap]

Supposedly the green Pocillopora damicornis is the really invasive one (doing a bit more reading on it, it seems that it grows fast, and then occasionally its shaded polyps bail out and land in various different places around the tank, growing into their own colonies). The link below has an example or two (there are plenty more links if you look around a bit):

Pocillopora gone rogue

A few days ago, I had a pocillopora frag (yes it has totally encrusted that frag plug and is even growing on the underside of the frag rack) make contact with a monti cap on the same frag rack and it pretty much melted the monti where it made contact. I moved the monti but the poci has been...

www.reef2reef.com

thank you! will definitely be exploring this further and when possible keeping updates