Blue Leg Behavior & The Annoyed Digi

[Uriken]

Hello my fellow reefer gang. I did a quick search on my issue before posting and actually found a post from 2012 with another member having the exact same issue yet the responses and feedback still left some questions thus I'm trying to see if I can get any more information.
I purchased a 1" inch red Digi about 6 months ago and its grown out a good 6" inches with several branches to this point. Very bright red and healthy. In my reef I have the standard cleanup crew with various snails and some blue leg crabs. They all been in there doing their thing for many, many months. As of late there is "one" blue leg in particular that has started climbing my digi and I find him constantly on the top tip of the branch. I thought he was stuck and removed him the other day yet he goes right back. The digi at the end of that branch wont extend its polyps with the crab being on it and is annoyed because of it. I remove him and place him on the other side of the tank and he goes right back over & over. There has to be something about the coral he likes or he is benefiting from that its the only thing the crab now does. The tips have the typical white cap from the ongoing growth yet I'm wondering if within that there is some type of food or something that is driving him to be there? I'm familiar and understand the makeup of the SPC and their internal coral skeleton and not aware of blue legs feeding off these corals. The crab has food that I make sure is available but its not interested in it anymore like the rest.
If anyone has any thoughts please let me know. Its getting a bit annoying and I'm ready to rehome the crab so the digi can get back to full polyps and growth again.
Happy Reefing everyone.

 

[livinlifeinBKK]

Hello my fellow reefer gang. I did a quick search on my issue before posting and actually found a post from 2012 with another member having the exact same issue yet the responses and feedback still left some questions thus I'm trying to see if I can get any more information.
I purchased a 1" inch red Digi about 6 months ago and its grown out a good 6" inches with several branches to this point. Very bright red and healthy. In my reef I have the standard cleanup crew with various snails and some blue leg crabs. They all been in there doing their thing for many, many months. As of late there is "one" blue leg in particular that has started climbing my digi and I find him constantly on the top tip of the branch. I thought he was stuck and removed him the other day yet he goes right back. The digi at the end of that branch wont extend its polyps with the crab being on it and is annoyed because of it. I remove him and place him on the other side of the tank and he goes right back over & over. There has to be something about the coral he likes or he is benefiting from that its the only thing the crab now does. The tips have the typical white cap from the ongoing growth yet I'm wondering if within that there is some type of food or something that is driving him to be there? I'm familiar and understand the makeup of the SPC and their internal coral skeleton and not aware of blue legs feeding off these corals. The crab has food that I make sure is available but its not interested in it anymore like the rest.
If anyone has any thoughts please let me know. Its getting a bit annoying and I'm ready to rehome the crab so the digi can get back to full polyps and growth again.
Happy Reefing everyone.

I had a blue leg get on my blue digi like that! I ended up moving him to another tank

 

[Chrisv.]

I have this exact scenario going on right now. Blue leg hermit on digi. doesn't seem to be eating it, just...chilling. I am sort of done with blue leg hermits and hermits in general. I removed them from one of my tanks to see if there would be a negative consequence. After a month, everything is fine. Maybe I can banish them to the back compartment of my AIO, and allow them to live out their remaining days eating detritus in darkness. Seriously, done with them.

 

[Uriken]

To totally banish them is a tough one for me as I feel for my tank they do their share of work to help maintain the tank. I do know that many crabs sold today at the various pet stores can say blue legs or scarlets and they are actually neither and some of these "other" types of hermits can be problematic. But this one is a legit blue leg and its puzzling with this behavior. Especially after he's been in there for many months. The way that it will migrate across the reef in my tank over and over and right back to that position on the tip of that Digi has me thinking there is something more to this going on. Its just the one crab over and over. The others can care less. Very puzzling.

 

[Chrisv.]

To totally banish them is a tough one for me as I feel for my tank they do their share of work to help maintain the tank. I do know that many crabs sold today at the various pet stores can say blue legs or scarlets and they are actually neither and some of these "other" types of hermits can be problematic. But this one is a legit blue leg and its puzzling with this behavior. Especially after he's been in there for many months. The way that it will migrate across the reef in my tank over and over and right back to that position on the tip of that Digi has me thinking there is something more to this going on. Its just the one crab over and over. The others can care less. Very puzzling.

I'm 100% sure mine is a proper blue leg. No idea why he is making such a nuisance of himself. I thought mine were doing a lot of heavy lifting, but honestly I think the lions share of the work in my tank is being done by a single turbo snail and a massive heard stomatella and trochus that are breeding in the tank.

 

[livinlifeinBKK]

I'd be interested in learning why they do this...not that I plan on moving my blue legs back into my reef tank to find out though...

 

[Chrisv.]

I'd be interested in learning why they do this...not that I plan on moving my blue legs back into my reef tank to find out though...

I almost wonder if it's due to lack of algae. Maybe they are climbing to high/bright spots in hope of finding more food.

 

[Uriken]

I know the easy thing would to be just pull the one hermit out and relocate to another tank yet I been in the hobby so long its this kind of "different and abnormal" stuff that I have the need to want to investigate and solve. Im on the path now to really dig into the Digi coral and what may be different about it (if anything) that hermits tend to do this with them. As of now I found 4 people that have this going on.

 

[livinlifeinBKK]

I almost wonder if it's due to lack of algae. Maybe they are climbing to high/bright spots in hope of finding more food.

That sounds possible but it's interesting that it seems to be digis in particular that they climb on

 

[livinlifeinBKK]

I know the easy thing would to be just pull the one hermit out and relocate to another tank yet I been in the hobby so long its this kind of "different and abnormal" stuff that I have the need to want to investigate and solve. Im on the path now to really dig into the Digi coral and what may be different about it (if anything) that hermits tend to do this with them. As of now I found 4 people that have this going on.

If you find out anything please post...I'd love to hear what you find!