Linckia laevigata diet unlocked?

[jap783]

I am documenting the progress I have been making with the sea stars in my reef. Once I saw a picture of one eating an Asterina sea star, I wanted to give them a try. However, there are multiple issues when it comes to feeding them. The first issue: are they specialist or generalist feeders? Personally, I believe they are a little of both but further research will be needed. The second issue, and one I believe is missed by many echinoderm novices, they cannot compete with most organisms for food.

After a trip to the store to buy salt, the salesman pointed me to several linckias he had forgotten about in a sump for several months. They all looked healthy and were well past the initial transportation mortality event. One evening, I noticed it was scavenging on a dead anthias after the lights were out. I didn't take out the anthias since it was the first time I had seen it eating but by morning the other inhabitants stole the prize.

I decided to try using Masstick as it worked well for my orangespot filefish. It doesn't float away in the current, and I can place it on anything. I placed Masstick on a coral plug, placed that and the sea star in a floating basket I used to isolate my magnifica anemones. I made several time lapse videos over the year to document how it feeds. The whole process could take up to 12 hours, so I just leave them in there overnight.


I tried the same technique with a Fromia species but was unsuccessful after 3 months. Echinaster tho, seemed to adapt well to this regimen.

Fromia

Echinaster


A few notes to add: while these sea stars have proven to MOSTLY be reef safe, I have noticed a few exceptions. Pineapple sponges and asterina stars are not the only things we keep that they eat. I was keeping a Caribbean yellow ball sponge that kept developing mysterious spots on its surface after the sea star was seen on top of it. This continued until the sponge was completely devoured over several months. However, yellow finger and red ball sponges seem to be off the menu. It also ate what remained of a grafted plating montipora but has not touched the 3/4" baby derasa.

This is not a keeper's guide for sea stars but a kicking off point for what echinoderm care could be like. There's still plenty more to learn about diets for this species and many other species we attempt to keep. Not to mention the special care that has to be considered for interloping tankmates!

 

[ISpeakForTheSeas]

Yeah, they'll eat Aquilonastra ("Asterina") stars, sponges, tunicates, etc. They're thought to be biofilm eaters in the wild, but - as you've noted - they'll occasionally scavenge for food too:

Yeah, some people believe that the "Asterinas" (technically Aquilonastras) the Linckias eat allow their stars to survive in their tanks - I've suggested people may want to try farming them to feed their Linckias as a result. They likely do also eat tunicates and sponges, as those tend to be bacterial sinks (so they'd basically replicate biofilm for the stars to feed on).

Genuinely glad to hear they're doing well for you - please keep us updated on how it goes, as most of the time I've heard these stars typically die off around ~8-13 months in our tanks (though I've heard of them making it to ~2-3 years if there are Aquilonastra stars in the tanks with them - they seem to basically wipe the Aquilonastra population out after/around that time).

One important thing to keep in mind with foods for these guys - just because they eat it, doesn't mean it's meeting their nutritional needs; it might be, but it might not be. With how long it seems to take these guys to starve, unless you're monitoring their health closely, you might not notice if it's not meeting their needs until it's too late.

Some ways to potentially gauge the health of the starfish that may be useful:
1 - Visual: is anything visually wrong with the specimen? (From what I know of starfish, these cues are generally pretty obvious if they're there at all - if the starfish is disintegrating, there's something wrong). [Edit: you may also be able to tell if the star is looking lean/gaunt or full/puffy; gaunt is generally not good.]
2 - Weight: is the specimen putting on or maintaining weight (generally healthy), or is it losing weight (under most circumstances, this would be unhealthy)?
3 - Size/Length: if it's not already full size, is the specimen growing? Is it shrinking (either from weight loss, disease, limb loss, etc.)?
4 - Reproduction: is the specimen engaging in reproductive behaviors/activities (i.e. courting, nesting, spawning, etc.)? (I recognize this one is not as common of an indicator in captive starfish at this point, but there are a few instances of starfish attempting to spawn in captivity).
5 - Longevity: is the specimen relatively close to meeting, actually meeting, or exceeding their expected wild lifespan (or at least surviving for a few years - healthy), or is the specimen dead/dying prior to doing so (unhealthy)?
6 - Speed: how quickly can the specimen right itself when it's flipped over?
7 - Level of activity: how much is the specimen moving around? (Generally speaking, low activity indicates poor health; moderate activity indicates good health; and high activity indicates good health but probable stress - it could be searching for food, oxygen, etc., but it's probably not in terrible health when moving a lot).
8 - Grip strength: does the specimen have a strong hold/grip with its tube feet? (A strong grip indicates good health, a weak grip indicates poor health).
9 - Willingness to eat: is the specimen eating? (Seems obvious, but can be really hard to tell with some stars - some stars leave little trails called feeding scars through the things they're eating; sometimes you can see their everted stomachs; other times, like if they're feeding on biofilm, you may not be able to tell at all - them crawling onto visible food is a good sign they're willing to eat, but - as mentioned above - the food may or may not meet their nutritional needs).

 

[Gray Levison]

There's actually an article pertaining specifically to this species in the article section. Just look under the "Inverts" section and it's the first article that'll pop up. I'm actually about to reread it.

 

[Gray Levison]

Linckia laevigata: An Analysis of Plausible Causes of Mortality in Captivity

I think I found the guy who wrote it on IG. He just started an account to post dive pics and discuss other topics similar to the one in the link above.

 

[jap783]

The linckia will be turning a year old in March with an original arm length of about 2.5 inches. It has been feeding on a dime sized amount of Masstick every two weeks. It is a very active feeder as can be seen in the video. Between the two videos, there are seven clips of the linckia eating the Masstick, even choosing it over Reef Frenzy, algae wafers, silversides, and mysis shrimp.

I have not been monitoring its growth closely but it only grew a few millimeters from last year. Part of the arm was destroyed by my powerhead but it healed very quickly.

I just felt it was important to share a rare video of a linckia not eating just once but the same diet over many months. Hopefully there will be many more!

 

[ISpeakForTheSeas]

The video didn't attach.

Are there still Aquilonastra ("Asterina") stars in your tank with the Linckia? How about sponges or tunicates?

 

[jap783]

Are the videos in the original post not visible? Or are you referring to my last post? I'll try and post all three again.

Blue Linckia Feeding

Echinaster and Linckia Feeding

 

[ISpeakForTheSeas]

Are the videos in the original post not visible? Or are you referring to my last post? I'll try and post all three again.

Blue Linckia Feeding

Echinaster and Linckia Feeding

Ah, I was referring to your last post not realizing you were meaning the videos in the first post (those work fine).