Sump macroalgae covered in micro sea spiders

[Bugenar]

I just finished my war with the red planaria, and now this…

I saw baby cardinal fish in my overflow and saved them, grabbed macroalgae from the sump for them to hide in, and saw these little spiders all over… There is a healthy pod population in both my tank and the sump.

I swear I’ve seen these before in my tank but I lost it and never saw it again. no lps or sps deaths. zoas, acans. polyp coral are all healthy

 

[Louis Z]

Are all those legs? Spiders have 8

 

[Bugenar]

Are all those legs? Spiders have 8

Not sure if they have 8 or 6, looks like this guy is missing some. Looks like its supposed to have 8 though

 

[BeanAnimal]

Maybe this will help?
https://animalfact.com/sea-spider-pycnogonida/
Sorry the site is add riddled insanity, but has decent information to get you started.

 

[Michael Hughes]

Yes, these are pycnogonid sea spiders. I do see 8 legs in your photo.

These are interesting taxonomically, because like horseshoe crabs, they are not actually true crustaceans. Instead they are grouped in subphylum Chelicerata (along with horseshoe crabs, scorpions, and true spiders). They seem to be scavengers and/or predators of bristleworms and other small invertebrates. I did read they can parasitize anemones. Have you noticed them feeding on anything in your tank?

 

[Privateye]

These are always cool! IME a regular iodine-based coral dip kills them.

I've only seen them in person once. I bought a yuma mushroom from Top Shelf, and after I dipped it I noticed 4 dead sea spiders in the cup. Since mushroom corals are actually anemones, I feel confident that at least the ones I had were not good for anemones.

 

[Bugenar]

Yes, these are pycnogonid sea spiders. I do see 8 legs in your photo.

These are interesting taxonomically, because like horseshoe crabs, they are not actually true crustaceans. Instead they are grouped in subphylum Chelicerata (along with horseshoe crabs, scorpions, and true spiders). They seem to be scavengers and/or predators of bristleworms and other small invertebrates. I did read they can parasitize anemones. Have you noticed them feeding on anything in your tank?

I have many bubble tip anemones, a few carpet nems, and plenty of aiptasia… oddly enough tho there’s like zero aiptasia in my sump where I found them.

No issues with anything in my tank, and it’s safe to assume my tank is infested with them lol…

I am concerned if they will prey on my berghia nudibranchs