New Clam wierd behavior

[OrionN]

a4twenty,
Living things responses to stimuli as if they are in the wild. The plant do not know that they are in your kitchen or on the bottom of the forest floor (where most of the house plants originated which is low light requirement).

Regarding Trinacda clams, they evolved over million of year on the natural reef. They do not move. As a larvae they settle somewhere, they either live and thrive or die there. They do not move higher or lower once they settle on the reef. They do have minimal mobility but cannot move to any appreciable distance and certainly cannot climb up. If they move at all, it is down because gravity.
In the natural reef, light intensity does not change very much in within the distance the clam can move or extended it mantel. The sun is so far away that a mile or two is of no significant decrease in intensity. It is the amount of water and air that the light have to go through that affect the intensity of the light. A inch or two (distance the mantle can extent up by the Crocea we are talking about) in dept on the natural reef is of no significant different in light intensity. It is much more advantageous to the clam to extend it mantle sideways to increase it's light gathering capacity than upward which result in no increase in intensity of light.
As I pointed out earlier, the clam no longer does this while under the same light and still on the sand, therefore it was not the light that cause it to do it.

 

[evsalty]

You do realize that croceas live in inter tidal areas and can actually be exposed to air and direct sun for parts of the day. Thus why they are recommended to be kept as high up in a tank as possible. The secend set of pics are top down pics and do not show in anyway whether or not the clam is still extending.

The op's tank isn't super deep so all in all it will probably be fine.

 

[evsalty]

Here is a quote about placement from RK. He does admit it's not an absolute. Also in the same article it talks about light and says that while 175w mh's can allow you to place near the bottom of a 24" or less tank he recommends the use of 250's or better yet 400's if doing so.

Finally, we get to placement. I think it's best to place any species on the same sort of substrate that you'd find it living on in its natural habitat, and croceas are never found on sand. I've never found one living on rubble, either; they live on (in) hard substrates only. So, a crocea should be placed on a solid substrate, if at all possible, where it can attach itself firmly to one spot as it would do in the wild. A flat piece of live rock or coral skeleton works very well, but a piece of tile can also be used. It may take anywhere from a few hours up to a couple of weeks, but a healthy clam will usually attach itself with at least a few byssal threads, or maybe many. I'm not suggesting that you absolutely must to do this by any means, but I do recommend it.

 

[OrionN]

evsalty,
Crocea can tolerate very high light level, but don't have to have that light level to thrive. I certainly keep plenty of clams and have keep all species of Trinacda and have keep them for many years.
The second set of pictures are not directly top down, and I can see that the mantle is not extended like the first picture.
Here are two of mine that I have in a 30 g tank right now at home. A Crocea and a Maxima

 

[Day With 2 Suns]

Position

Position

Just curious my 2 clams (Maxima) are 14 inches from the bottom of the light, a 150 MH (Solana Tank) and they are well extended over the side. Does this mean I need to move them closer up to the light?? They seem healthy and fine. Color is good no bleaching?

I have the ability to lower the light.

 

[OrionN]

They can take more light but if they are growing well I would not worry about it. The two clams above are on rock higher up but not righ under the light 150W DE 10000K MH.
The higher up they are , the less beautiful they are due to the angle of view. Most of my clams, both Crocea and Maxima are on the bottom of the tank, on the sand. They do fine without problem 14-18 inches from 250W MH or 150W MH. I change water often so my water is not yellow, and I change bulbs every year so no old bulb for me. For my 150W tanks, I make sure the clam is right under the light. More light penetration and virtually no reflection of the light if the angle is at 90 degree.

 

[a4twenty]

<a href=showthread.php?s=&postid=15485541#post15485541 target=_blank>Originally posted</a> by evsalty
Judging by the pics the clam is still on the sandbed. His statement of moving him 5" was made on the 2nd and his pic of the whole that he was concerned about after the move was on the 3rd.

i assume he was just asking about the "new hole" and not showing the clams new 5" higher position.

<a href=showthread.php?s=&postid=15485617#post15485617 target=_blank>Originally posted</a> by OrionN

Living things responses to stimuli as if they are in the wild.

absolutely and the crocea clam responds to less than ideal lighting conditions by raising his mantle toward the light source.

<a href=showthread.php?s=&postid=15485617#post15485617 target=_blank>Originally posted</a> by OrionN
Regarding Trinacda clams, they evolved over million of year on the natural reef. They do not move. As a larvae they settle somewhere, they either live and thrive or die there.

i agree, that is why crocea's are only found in 10' or less of water. where light intensity and spectrum are ideal.

<a href=showthread.php?s=&postid=15485617#post15485617 target=_blank>Originally posted</a> by OrionN
In the natural reef, light intensity does not change very much in within the distance the clam can move or extended it mantel. The sun is so far away that a mile or two is of no significant decrease in intensity. It is the amount of water and air that the light have to go through that affect the intensity of the light. A inch or two (distance the mantle can extent up by the Crocea we are talking about) in dept on the natural reef is of no significant different in light intensity. [/B]

as stated above, the clam reacts to stimuli, they have no brain. they can't rationalize that the 1" - 2" wont help, they are just reacting to the less than ideal lighting conditions.

<a href=showthread.php?s=&postid=15485617#post15485617 target=_blank>Originally posted</a> by OrionN
It is much more advantageous to the clam to extend it mantle sideways to increase it's light gathering capacity than upward which result in no increase in intensity of light.

you may think that but again, the clam cannot rationalize. the crocea is well known / documented to extend their mantle much more than other species of clam, under sufficient lighting and IME with crocea clams under 400W 10K halides at depth of 16" - 30", the clam will extend / drape their mantle sideways to bask in the light.

<a href=showthread.php?s=&postid=15485617#post15485617 target=_blank>Originally posted</a> by OrionN
As I pointed out earlier, the clam no longer does this while under the same light and still on the sand, therefore it was not the light that cause it to do it.

unfortunately, that's a complete contradiction of the OP's statement......



as i said above, either way i hope the clam is doing fine, though lack of response by the OP and the fact the clam was kept under compact fluorescents doesn't give me much hope.

 

[OrionN]

<a href=showthread.php?s=&postid=15533444#post15533444 target=_blank>Originally posted</a> by a4twenty
..
as i said above, either way i hope the clam is doing fine, though lack of response by the OP and the fact the clam was kept under compact fluorescents doesn't give me much hope.

Per flameangel9 the light set up for this tank is
Current USA 48 inch Outer Orbit 2x150w 10K HQI-MH w/ 4x54W T5 HO & 18 Lunar Lights
Can't you see that the clams have enough light and that extend upward are not due to lack of light. It got plenty of light with MH and T5. You seem to mis-read his information on his light set up then argue until you gill turn blue. No more by me on this subject.

 

[a4twenty]

<a href=showthread.php?s=&postid=15533509#post15533509 target=_blank>Originally posted</a> by OrionN
Per flameangel9 the light set up for this tank is
Current USA 48 inch Outer Orbit 2x150w 10K HQI-MH w/ 4x54W T5 HO & 18 Lunar Lights You seem to mis-read his information on his light set up ...

or did you miss this???

<a href=showthread.php?s=&postid=15462677#post15462677 target=_blank>Originally posted</a> by flameangel9
I bought this clam from a fellow reefer. He was in a 70 gal tank that was taller than mine. He was on the sand under compact flourescents.

what i said was the clam was kept under PC lighting, again i am only stating what the OP said. light deprivation in clams can take months or longer to show before slowly killing the clam.

<a href=showthread.php?s=&postid=15533509#post15533509 target=_blank>Originally posted</a> by OrionN
Per flameangel9 the light set up for this tank is
Current USA 48 inch Outer Orbit 2x150w 10K HQI-MH w/ 4x54W T5 HO & 18 Lunar Lights
Can't you see that the clams have enough light and that extend upward are not due to lack of light. It got plenty of light with MH and T5.

you also must have missed this.....

<a href=showthread.php?s=&postid=15482016#post15482016 target=_blank>Originally posted</a> by a4twenty
i assume the T5's are actinics, so they don't really add to the usable light, especially at the bottom of the tank. in a 75G ( 22" deep?? ) this probably is on the very edge of required lighting to keep a crocea so deep. results may vary ( especially by species ) based on individual clam but i wouldn't suggest keeping croceas so deep under your lights.

i didn't say it was not possible, just not recommended. i think you'll find if you look around the web, many others agree

<a href=showthread.php?s=&postid=15533509#post15533509 target=_blank>Originally posted</a> by OrionN
then argue until you gill turn blue. No more by me on this subject.

i'm not arguing, it's you that has taken a stand and refuses to listen to the information provided by the OP and others around the web.

if you want to be done with this thread, just stop posting in it.

for the rest of you, i'll post some links to perfectly healthy crocea clams, under more than sufficient light ( wild / tanks ) that are extending their mantles sideways. this is perfectly normal behaviour for this species of clam.

all linked pictures are from author James Fatherree's collection.