What allows clams to react to light?

[RobSW1]

Ive always wondered why clams "jump" in response to light. Is there an organ in the clam that senses light? if so what is it.......this has always confused me and i was just wondering if you guys/gals could shed some light on the subject

thanks
rob

 

[a4twenty]

they have eyes, they cannot see as we do but can see shadows and incoming fish etc......

their eyes are on those little bump on the mantle, you probably cannot see them but they see you

 

[RobSW1]

that is crazy, i thought it was some sensory organ inside, not actual eyes on the mantle. thanks man, but are the eyes the little irredescent colors you see on the clam?

thnaks
rob

 

[a4twenty]

<a href=showthread.php?s=&postid=9828373#post9828373 target=_blank>Originally posted</a> by RobSW1
but are the eyes the little irredescent colors you see on the clam?

they are part of but not really the eye. take a super close look at the dots surrounding the mantle of your clam. ( here's an old pic of one of my maxima's )

here's a pic of their eyes on the little bumps of maxima and crocea mantles. you can really see the eye in the lower left dots, it appears as a small dot inside a whitish circle. ( my camera isn't that great )

the small black dots surrounding the derasa's mantle

and the much more noticeable eyes of the gigas ( black dots circled with the beautiful color )

as i said above they are a very simple eye, they can see shadows and movement but cannot focus in on objects.

 

[RobSW1]

thanks so much...ive been wondering for so long but felt stupid for asking

thanks
rob

 

[a4twenty]

don't, how else can you learn stuff

 

[Red Sea Purple Tang]

Wow....

 

[prugs]

Anthony,
Notice the stretch marks on my gigas & a4twenty's.

My gigas is the least responsive to light change. It will allow fish to swim right over & even brush the mantel gently without reaction. But if the gigas get bumped or the lights go out, it closes up.

 

[acrodave]

i think the longer they are in a tank the stop doing it as much i have seen clowns trying to host in them they hated it at first and they just gave in and let them swim in them. but if u walk over to look down on them they close up

 

[cainchristy]

Wow that's great. I just got a Crocea clam and wondered what triggered that response. Very interesting, thank you. Here is a picture of mine, sorry a bit blurry due to my cam being terrible at macro zoom. http://i148.photobucket.com/albums/s7/RyanSc_photos/IMG_0925.jpg
Also it was hard getting a good pic from on top with the lights on. I know it's not the most beautiful Crocea but compared to the others I see ( I work at SW LFS ) it was unique. I am having some problems with placement, SPS, tons of flow, are not helping with this. Thanks.

 

[oldreefer76]

Great info thanks always wondered the same myself, I Love it I can learn something new on a daily basis

 

[CMcNeil]

<a href=showthread.php?s=&postid=9907780#post9907780 target=_blank>Originally posted</a> by acrodave
i think the longer they are in a tank the stop doing it as much i have seen clowns trying to host in them they hated it at first and they just gave in and let them swim in them. but if u walk over to look down on them they close up

i just posted about my clown trying to host my derasa.i saw him pearched on the mantle this morning.

 

[israelnajar]

That's crazy.

I always thought the response was due to a chemical reaction of some sort in the symbiotic algae in the clams mantle.

But you guys smacked me down. At least I know for a fact why they do it.