How does Sea Star Poop?

[Kumaran]

How does Sea Star Poop?

I got confusing answer from online forums?


Some says it has anus at the aboral side.

Others says it through out the waste through mouth.


Can anyone answer?

I am very new to salt water tanks... Just in learning phase.


I just started a nano tank 4 months back.

But

 

[ISpeakForTheSeas]

It depends on the starfish and what they eat:
Many (but not all) starfish have an anus on their back in the center (opposite the mouth, which is in the center on the star's front), and they do use it - but it is small, and most of their excretion is done by simply diffusing gas through permeable parts of the body (i.e. they release waste gases through their skin and possibly their tube feet as well - I know other echinoderms use their tube feet too, but I can't seem to find any confirmation on if starfish use their tube feet for this or not).

For predatory stars that eat things like snails, clams, etc. they sometimes will swallow their prey whole (meaning they will swallow the entire snail/clam/etc. - shell and all), wait for their prey to die from oxygen deprivation (so they can access the meat inside the shell they swallowed), digest the meat, and then spit the shell back out through their mouth.

In brief, most starfish do poop, and at least some of the predatory ones do spit non-digestible things out through their mouths, but stars mostly just digest everything and excrete the waste as gas.

 

[Kumaran]

It depends on the starfish and what they eat:
Many (but not all) starfish have an anus on their back in the center (opposite the mouth, which is in the center on the star's front), and they do use it - but it is small, and most of their excretion is done by simply diffusing gas through permeable parts of the body (i.e. they release waste gases through their skin and possibly their tube feet as well - I know other echinoderms use their tube feet too, but I can't seem to find any confirmation on if starfish use their tube feet for this or not).

For predatory stars that eat things like snails, clams, etc. they sometimes will swallow their prey whole (meaning they will swallow the entire snail/clam/etc. - shell and all), wait for their prey to die from oxygen deprivation (so they can access the meat inside the shell they swallowed), digest the meat, and then spit the shell back out through their mouth.

In brief, most starfish do poop, and at least some of the predatory ones do spit non-digestible things out through their mouths, but stars mostly just digest everything and excrete the waste as gas.

Thank you so much.... I have been searching for answers for days together...

One more question : do sea star eat algae?

 

[ISpeakForTheSeas]

Thank you so much.... I have been searching for answers for days together...

One more question : do sea star eat algae?

Some do and some don’t. Is there a specific sea star you want/have?

 

[Kumaran]

Some do and some don’t. Is there a specific sea star you want/have?

blue linkia star, Red-knobbed starfish

My LFS have this two....

I am planning to buy any one...

So doing all the research....

As far I learnt blue linkia star.... Dies within a year due to their unknown special requirements.

 

[ISpeakForTheSeas]

blue linkia star, Red-knobbed starfish

My LFS have this two....

I am planning to buy any one...

So doing all the research....

As far I learnt blue linkia star.... Dies within a year due to their unknown special requirements.

Yeah, Linckia stars eat biofilm and we can’t really provide that for them (some people with really big tanks get lucky enough that their tank naturally produces enough feed for the star, but that’s only some people and usually with very large tanks), so they usually die off.

For the Red-Knobbed Starfish, they don’t really eat algae from what I can tell (see my quote below):

The Red-Knobbed Starfish (Protoreaster linckii), on the other hand, “is considered as a voracious scavenger, mainly feeding on sponges, sea anemones, soft corals, etc. It is considered as an enemy of pearl oysters along the coast of the Gulf of Mannar.”*
* My source: https://www.researchgate.net/public...dea_Tuticorin_coast_south-east_coast_of_India

 

[Kumaran]

Some do and some don’t. Is there a specific sea star you want/have?

1. )Red knob sea start / blue linckia ..... Any one of them...

2.) About Algae eating star fish....in Internet there are scrambled information about star fish eating algea... But i couldn't find any specific algae eating star fish...

 

[Kumaran]

Yeah, Linckia stars eat biofilm and we can’t really provide that for them (some people with really big tanks get lucky enough that their tank naturally produces enough feed for the star, but that’s only some people and usually with very large tanks), so they usually die off.

For the Red-Knobbed Starfish, they don’t really eat algae from what I can tell (see my quote below)

I am going to get red knob mostly.

Is there any specific sea star that eats algae..... Internet says star fish eats algae... But I couldn't find any specific sea star that eats algae...?

 

[ISpeakForTheSeas]

I am going to get red knob mostly.

Is there any specific sea star that eats algae..... Internet says star fish eats algae... But I couldn't find any specific sea star that eats algae...?

I know some people have kept Goniaster tessellatus with long term success by feeding them algae and algae pellets (this starfish has about a thousand common names, but the one person I know currently keeping one refers to it as the West African Biscuit Starfish - this common name may also refer to a different species).

 

[Kumaran]

I know some people have kept Goniaster tessellatus with long term success by feeding them algae and algae pellets (this starfish has about a thousand common names, but the one person I know currently keeping one refers to it as the West African Biscuit Starfish - this common name may also refer to a different species).

Ok. Goniaster tessellatus I will check with my LFS. I have never seen this at my LFS.

 

[AydenLincoln]

I know some people have kept Goniaster tessellatus with long term success by feeding them algae and algae pellets (this starfish has about a thousand common names, but the one person I know currently keeping one refers to it as the West African Biscuit Starfish - this common name may also refer to a different species).

That person is me! OP hasn’t been in the forum since posting this but I changed his diet after speaking with experts. I feed him krill soaked in plankton as well as clams, masstick, and occasionally he finds fish food. I can confirm though their natural diet is not algae but rather microorganisms found in the sediment…I will say he is not picky in what he eats and whatever I give him he will eat.