Is my Crocea over extending?

[ryan115]

I know croceas extend their mantle further than other tridacnids, but i was wondering if this is a little to much. Sorry for the blurry pics.
(the second pic is from a little underneath, so it looks a little further out than it is, but not by much)

 

[Peabody]

I have to say a definate yes....tridacnids usually don't usually extend upwards towards the light like that, they simply open up, not reach out.

What is your lighting setup?

 

[ryan115]

4 x 39W T5. The crocea is up near the top of the tank, about 8"-10" from the lights. While my other crocea lower in the tank is doing great. Looking back at that pic, the angle is very decieving, I will try to get a level pic to better show the clam.

 

[Peabody]

Another pic might help. The first pic looks fair, but the second pic really makes it look like he's "reaching upwards".

I assume you have 2 daylight bulbs and 2 actinic? If so, 2 39w daylight bulbs seems low, though I admittedly have little T5 experience

 

[Peabody]

double post...sorry!

 

[a4twenty]

sorry, i don't think it's the angle. he is definitely overextended or there is a powerhead aimed at him.

 

[Peabody]

double post...sorry....RC is being weird for me tonight.

 

[ryan115]

here are some more level pics

 

[Peabody]

Yeah, he's reaching. Maybe try him in a different spot. Get him right under a daylight bulb, as high as possible.

 

[a4twenty]

<a href=showthread.php?s=&postid=8506881#post8506881 target=_blank>Originally posted</a> by ryan115
While my other crocea lower in the tank is doing great.

it may look like he's doing great, but he probably is not. crocea's like a lot of light you should probably move him up also. here is a pic of my crocea on the bottom of a 24" deep tank, see the way his mantle just sort of flows out of the shell.

 

[Peabody]

Nice pic. That shows how normally croceas simply "spill out" of their shells and do not "reach up" towards the light.

 

[ryan115]

upon closer inspection, only half of the mantle is being over extended. The half that is away from the middle of the lights is lifting to face the middle of the tank. I will try to find a spot closer to the middle of the tank this weekend. Just for my info, what problems can arrise from a tridacnid that overextends?

 

[Peabody]

Well, it doesn't exactly cause problems...it is a symptom of a problem: Low light. Low light can lead to the ultimate demise of the clam since it's their food source. They hang on for a while and then die very suddenly.

Other than upgrading lights, your current plan is the best chance.