Is this normal?

[aberg12012]

I am being overly cautious here... but I've notticed that the very center of my crocea's mantle lacks it's normal blue coloring... is that normal? I'm worried, thinking maybe my 2x175 Ushios, 1x110watt vho actinic, and 2x55 watt pc actinic isn't enough for this clam. I've been waiting on another set of end caps to add the other 10k VHO tube for some extra full specturm light...

Again, being a little too paranoid, I know, but just thought I'd see if anyone sees any problems with my clam, since I finally got some photographic equipment to post decent pics.

 

[kfisc]

great pics- speaking from a whopping 1.5 years' experience with tridacnids, yours does indeed look just slightly bleached in the middle, but offsetting this is great mantle/siphon extension; is it gaping at all? I can't quite tell from the photo, but it looks as if it may be...

 

[Herbert T. Kornfeld]

I have a few that did that too. I was concerned, but they were within 12" of a 250wattDE...so not the lighting! I checked all parameters...pH, phosphate, nitrate (they do like a little I hear), calcium, etc. I did some phyto feeding just in case...but they are still like that. I wonder as well (I was just about to post the same question). The good news is that the clams are doing fine otherwise, having grown a couple larger than normal layers onto their shells...and Ive had them for months now...no extra white areas developed. Any experts have an idea? Is there a parameter that we are overlooking here? Maybe temp. My temp is kind of high at 81 during the summer. What's yours at aberg?

 

[aberg12012]

is it gaping at all? I can't quite tell from the photo, but it looks as if it may be...

By gaping, please explain exactly what you mean. I'm just speculating, on either that it's (for lack of a better term) inlet "mouth" is open further than normal, or it's protruding it's mantle further than it should... Both of which I have been concerned with. I've had the clam for about 3 months now, and dosn't seem to be unhealthy, but then again, this is the first clam I have ever had, and I'm not experienced with them. It had been protruding it's mantle out quite far, untill I moved it a bit. Is it bad if it's sticking it's mantle out really far? Is that a sign of stress or something else like it's choking? Maybe it needs more calcium or alk? My alk and calcium are sub-optimal... Calcium runs around 350, and alk runs around 7-8, depending on if I've just added buffer or not.

My temp is kind of high at 81 during the summer. What's yours at aberg?

Same here... usually stays steady at 80... HOWEVER, lately Wisconsin temps have been very unpredictable. (When arn't they...) Some days when it's 85 out, the tank hovers up to 82, but never any more as after about 81.5 I start adding frozen water bottles to the sump to keep it under 82.

Then, on nights like tonight, when the temp in my apt drops under 70 the heater keeps the tank around 79.


Here's the run down on my water perameters:
PH: 8.4, and quite steady
DKH: 7-8
Calcium: 300-350
Salinity: 36ppm (Checked with Refracto)
Temp: Varies from 82 during a hot mid-day, to 79 at night.
Zero Ammonia, Nitrites, and Nitrates (And I'm also skimmerless.)
I may have some nitrates, but nothing detectable by the current test kit I have. (Under 5ppm.)

Because I'm skimmerless, I run carbon 24/7, and change filter media every 3-4 days. I feed DT's about once a week, some times more. I dump in 2 cap fulls with each feeding, tank is a 75.

 

[aberg12012]

Is there an experienced clam keeper that can reply here? Would be nice to just have some one chime in and either say "hay dummy... it's normal" or "you retard... you should know better than to not keep your calcium and alk levels higher!"

 

[AquAddiction]

Is there an experienced clam keeper that can reply here? Would be nice to just have some one chime in and either say "hay dummy... it's normal" or "you retard... you should know better than to not keep your calcium and alk levels higher!"

Lol.

Sorry I can't answer your questions as I am wondering the same thing about my 2 new Croceas. They look exactly like yours - slight central bleaching and possible gaping. Hopefully, the Giant Clams book by Knopp will answer these questions if no one can chime in. I'm thinking about ordering the book tonight.

 

[aberg12012]

Be sure to fill me in then!

 

[hwynboy]

Your crocea is not gaping...and it looks perfectly healthy...so yes I would say that you are being overly cautious.

 

[reefmarker]

Lol.

<SNIP>
Hopefully, the Giant Clams book by Knopp will answer these questions if no one can chime in. I'm thinking about ordering the book tonight.

Order the book. Great book for clams. Really lets you know how little we know about them! But what is known is in there. I have a crocea that has even more white than yours. Mine is all where the outer mantle sort of shadows the inner mantle.

I'm not sure that's not normal, but if it is not normal then:

Knop calls this "Local Bleaching." He says it is caused by a reduction of symbiotic algae but not by damage to the mantle. He says it is caused (they think) by reduction of light intensity but not by reduction of light quality. He also cautions about changing lighting quickly on any clam. So, if it is local bleaching you need more light intensity. He also says it will take a good while for it to get better.

 

[PUGroyale]

To be honest... I've seen this question posted a few times. The center of the crocea is the area of highest irridescence. Look straight down at your clam... I think you'll be surprised to find the center is not faded at all.

 

[Herbert T. Kornfeld]

oh, BTW aberg, Im in milwaukee\
on my clams...I doubt it is a need for more intensity...as I have a 250wattDE MH hanging right above them (in a 12" deep tank).

Is is possible that our refugium/macro algae filtration is competing for nutrients with the clam's algae?

 

[aberg12012]

Thanks all... I have notticed that at some angles, the center of the clam looks colorless, but at other angles, it appears more colorful. I'll relax about it now... thank everyone.

 

[Herbert T. Kornfeld]

heres what one of mine looks like from the front and then above...

http://www.nano-reef.com/gallery/showphoto.php?photo=4459