Algae ID please

[kirkwood]

The algae is brown and seems to just discolor the rock.. Not much outward growth otherwise... Just a few instances where its a growing on the rockwork. I had some zoa colonies get disturbed by this brown growth and form some kind of a crust irritant over the polyp preventing it from opening..

What is it? and what kind of CUC eats it???

In my 120g my current CUC is 7 emerald crabs, some blue/red hermits, 10-20 tsonga nassarius, 10-20 astrea

 

[acroholic]

Can't name it, but it is common in all reef tanks I have seen.

 

[ringo®]

Looks like diatoms to me. Aragocrete plugs?

 

[kirkwood]

Acroholic;919412 wrote: Can't name it, but it is common in all reef tanks I have seen.

I felt like it was pretty common too.. Algae wise my tank is in the best condition ever with basically no real issues of any sort whatsoever...

I've had some zoa irritation this summer and am trying to find the culprit... I do have 8 emerald crabs of which 2 males have gotten BIG (i'm trying to remove them).. and I've seen them cleaning around zoas with those huge claws... but I never see zoas that look like they have been eaten or nibbled... I just see some kind of a brownish crust/film growing over the polyp tissue (more noticeably on the tissue that grows in between the polyps).. I found some similar posts on RC but no definitive ID...

i have hit or miss success treating with peroxide dip and I'm still fine tuning a recipe/regimen... but i would rather find a cure than a treatment...

Edit:

Ringo®;919414 wrote: Looks like diatoms to me. Aragocrete plugs?

yes I use aragonite plugs... the algae is virtually non existent... You have to really search to find it growing on the live rock... I only have concern when I find irritated zoas... i always hear people mention that their zoas colonies "melted".. and I have witnessed that now a couple times... but I don't think it was a freak event.. I think it was caused by something... I'm unsure if diatoms can form a brownish "crust" over zoas...

this is 100% not cyano as I'm familiar with that and never had any issues with cyano negatively affecting zoas...

 

[acroholic]

Your big Emeralds could definitely be the culprit(s). They can be sexed pretty easily. I try to only buy females now. I have had the males clip off the tips of hammer and torch coral tentacles for no apparent reason before. Also had small fish disappear, and that stopped when I got the big males out of the tank.

 

[kirkwood]

Acroholic;919424 wrote: Your big Emeralds could definitely be the culprit(s). They can be sexed pretty easily. I try to only buy females now. I have had the males clip off the tips of hammer and torch coral tentacles for no apparent reason before. Also had small fish disappear, and that stopped when I got the big males out of the tank.

I agree.. i will only buy females from now on.. but since these emeralds helped me erradicate a bubble algae outbreak from initial tank setup phosphate issue from improperly cured rock, I can't really complain... I think when you have various sizes of BA you need various sizes of emeralds to eat them all... I literally have found the big males sitting on top of my Korralia's picking BA out of the screen guards... Logically since my BA is gone they could be looking for a new food source... I busted a male eating my spongodes at 6am with my phone flashlight this morning...

as it relates to zoas, I didn't think that irritation from emeralds could diminish the zoa health to the point where they would close up and have some kind of crust growing?? maybe the emeralds irritate them and little cuts in the zoa tissue get infected??? just brainstorming here...

so how do you catch an emerald??

 

[acroholic]

Kirkwood;919425 wrote: so how do you catch an emerald??

They really don't move much, so I have been able to snag them with a large pair of stainless steel tweezers I have.

 

[dball711]

Use your hands!

 

[acroholic]

dball711;919433 wrote: Use your hands!

The problem was the emerald being in a thin crevasse my hands could not reach into without setting off an avalanche of LR in the tank. Tweezers worked great for me and the LR structure stayed intact.

But hands would work as well if you can reach him.:yes:

 

[kirkwood]

Ive been trying the tweezer technique the past couple weeks. So far I've gotten 1 leg and 1 claw.

 

[kirkwood]

1 down, 1 to go...

I tried a small water bottle converted to a fish trap technique with mysis and nori... an hour after lights went out i had caught some tsongan nassarius and 2 female emeralds, but neither of the monster males were in sight...

at 6am today I scared a male off the rockwork and onto the sandbed.. I ditched the tweezers and grabbed him with my hand... he was the brasher of the two... now I just have to wait for the other to appear... I hope this is the mystery source of my zoa issues..