does this clam look healthy....and why do they always do this?

[Patman]

Hello all......just looking at my clams today and they look healthy to me, but people talk about gaping ..........and I hear mixed opinions about what it means when the intake is 'gaping'...does this look ok....the clam is always open (when light) and reacts to movement.......thanks

[Patman]

And the second question.......no matter where I put the two Derasa clams.....they always end up right next to each other.....touching mantles..........is this ok, there is no reason why they should irritate each other, right? they seem to stay open...thanks

[Alice]

I don't know much at all about clams, strange how they move towards each other all the time. Is that subtrate on the surface of the clams? I think I remember reading that sand/substrate will irritate them?

Anyway, this will bump it up so maybe a "clam person" will read your post

Alice

[Frank]

I have 7 clams in my 65 and 2 more at work. From what I have learned about clam they don't like anything on them. They will try to blow it off of them. All of mine are always opened your clams look great. Here is an article I found on clams That I thought was very good. http://www.reefcorner.com/introtoclams.htm hope this helps you.

[dbman]

Patman, that clam is not "gaping" by any means. It's normal for the incurrent siphon to be slightly open like that; when you see them WAY open such that you can see everything inside, it's time to start worrying.

Beautiful clams!

[dark horge]

Hi Patman.

Nice looking clams. Tridacna derasa, right?
To elaborate on what's already been said...

Gaping is when the clam seems to be tearing its own shrivelled flesh apart between the two 'gaping' shell-halves. Largely an issue of malnutrition. Your clams are looking good, and like dbman has already posted, the incurrent/inhalant vent is normal in aspect.

Regarding your second question... clams don't zap each pther when in contact. One small problem with keeping them close together is the convenience offered to potential parasites and pathogens.

They do need food, quite apart from good light to fuel their guest zooxanthellae. In many mature tanks, there's so much biodiversity that there's enough plankton in the water for the clam to filter out and dine on.

Otherwise, a clam can appear healthy for months, and then rapidly decline once its energy reserves are depleted. Some authors claim that zooxanthellar nutrition accounts for only up to 65% of a clam's energy needs.

I'm sure there are some commercial plankton preparations you can study and then acquire, for infrequent feedings. Otherwise, you can just ensure good rock and sandbed biodiversity.



hth,
horge

[Patman]

hey everyone,


Thanks for all of the input. I have had the first clam (more purple color) for about 7 or 8 months and the second for about 4 months. It's amazing to see the new growth of the shell......the smooth white coloration that quickly gets covered with coraline.....The tank was mature when I placedn the clams in (about 10 months old) and I hadn't really been feeding on a regular basis.....I used some DT's but that was really not giving me any amazing results...so I started with the spray dried phytoplankton.....just 3-4 times/week.......its cool because it forms all sorts of different particulate size when you put it in....anyway, my thoughts are that the clams are filtering from the rock/sand more than anything I am adding...

Thanks

Pat