T. Maxima tank-cultured ?'s

[Rovert]

I just purchased a very beautiful young (2 1/2") purple/blue tank cultured T Max from (of all places...) ThatFishPlace, while visiting for business in the PA area this past week.

One of the things that I noted was that the bottom of the clam was 'clean' in that you could almost see through the flat portion of the shell to the mantle. I didn't think anything of it until reading other posts, and now I'm a bit concerned.

Within an hour of introducing the clam to the tank, (s)he fully opened up, showing the mantle and the exhalation nozzle was pointing up, but the opeculum was gaping a bit. That eventually closed down, and all seemed to be well, but now only the slightest bit of mantle is showing.

Since I don't believe that my tank conditions have changed that dramatically in a day or two, I began reading up on the on sand / off sand debate.

Can someone confirm these issues for me:

On sand (southdown substrate) or on a piece of rock?
Feed w/ DT's, or hold off?
What does the byssal gland look like?]
Any special considerations for tank-bred clams vs. wild caught?

Thanks in advance!!!

[Rovert]

^

[Randy V]

Rovert, my experience is that clams go through adjustments as they acclimate to your tank conditions. Since they store their zooxanthela in their mantle, a clam that has been accustomed to a low light level will expose less mantle in a higher light environment until it manages to adjust. Also late in the daily lighting cycle it may pull its mantle in, since its light needs are met. So it depends what time of day you look at it.

I feed with DTs or other phyto product from day one. I can't see any downside to that. The bysal gland or foot is white and extends from the opening when it attempts to move or fasten. It is typically triangular to oval and extend about 1/2" to 3/4" on my 4" crocea. I'm sure they vary a little with species. I would assume that tank bred would be more used to artificial light sources but I am not sure about the terminology with these clams since many are grown in coastal reef waters by pacific island locals and may be considered "captive bred" but not "tank bred". My thoughts.

[TonyHNYC]

-On sand (southdown substrate) or on a piece of rock?
-Feed w/ DT's, or hold off?
-What does the byssal gland look like?]
-Any special considerations for tank-bred clams vs. wild -caught?


I put mine on a piece of rock....Within time, they will fasten themselves (for maximas and not my derasas). The byssal gland is white and usually shrinks when disturbed. In the past, I purchased only clams that are tank-bred for 2 reasons - Conversation of the nature environment and also, I think the tank-bred specimens are hardier and easier to adjust to tank environment.

[Rovert]

Thanks for the replies, guys. Sorry it took so long to respond, but I wanted to grab a few shots while I had the chance, to show what I'm talking about. Larger images are accessible on my web page (link above).

Here's the color morph (sorry about the blurry shot):
http://pws.prserv.net/usinet.kreisle/aquarium/72/72thumbs/clam-front_small.jpg

And, I'm not seeing anything that looks like a 'gland', unless it's the white ring around the opening here. Is that it, or do I have a hurt puppy here?
http://pws.prserv.net/usinet.kreisle/aquarium/72/72thumbs/byssus_small.jpg

Also, is this a normal shape for a clam? I was expecting something a bit more arc-shaped, and half circular, this seems to be a quarter-pie shaped. What do you think?
http://pws.prserv.net/usinet.kreisle/aquarium/72/72thumbs/clam-side_small.jpg

I'm a bit reluctant to put the clam on a piece of rock, because if I need to remove it, I don't want to damage it. Also, there seem to be other people who place T.max on the DSB, but I want to do whatever will give this fella the best chance of happiness.

Hope you can steer me in the right direction!



[Edited by Rovert on 05-21-2001 at 12:37 PM]

[Randy V]

The bysus gland is not the ring, it is retracted in the shot you posted. They don't extend it IME unless they are trying to move or have decided to stay put and start to attach. That is the normal shape for a tridacnid. I have no experience with maximas so I can't help you with placement. Is the mantle currently extended as in the top shot or fully closed like the bottom shot?

[Rovert]

Randy, you're saying that the byssus gland is there, though, right?

The mantle is almost always extended as in the top shot. The reason I'm concerned is because when it first went into the tank, it had opened wide, exposing it's inner lining and mouth. Now, it's kind of shut.

I recently noticed some bad behavior by my blue cheek blennie, which just insists on spitting sand on top of the clam, and generally making a mess of my tank. No matter how often I go in to clear off the sand from the clam, the blennie comes back around, takes a mouthful of sand, and sifts it on top of the clam. Could this be the source of the problem?

[Randy V]

I see nothing in the shot that you posted that indicates that it doesn't have its gland. It is simply retracted. The constant harrassment could definitely be the problem. Another reason you might want to consider moving it up onto the rocks. If the clam is normally extended as in the top shot and your lighting is stronger than what it is used to, that could be normal behavior as it acclimates. When you first get them they often gape and overextend their mantles in order to quickly gain energy as they have been stressed. I am no clam expert, but that has been my experience with croceas.

[Rovert]

Randy, thanks. Where is the T. Max found in nature - on rock on in sand?

[BurnNSpy]

Maximas are found on rock, they need to be attached . It may keep trying to attach and expend energy until it dies unless it finds a good attachment. Just use a small piece or rock that can be easily moved with the clam. Maxima clams do best in MH lit tanks also.

BurnNSpy

[Randy V]

Rovert, my only experience is with croceas, so I can't help you with placement. I don't know how to post links but there was a thread on this board towrd the end of last year that might help you. It was titled "T. Maxima owners please read".

[AASC]

I'm not sure if this helps or not but I had :( a Crocea that on arrival looked fine'n'dandy. I positioned it on a small piece of rock in a convenient depression. Everything was fine for 3 days then on day 4 it toppled over and left behind what I can only assume was its bissal gland, small 1x2cm cone of white/grey flesh partially attached to the rock. The base of the clam showed a matching cone shaped recess. Over the next 2 weeks the clam gradually lost it's colour, started to gape then ceased to respond to any light stimulus aka dead !

Fortunately I'd phoned the MO supplier on day 4 and I've a credit on file for a replacement.

[Rovert]

Gee, thanks, AASC. You're really giving me a lot to look forward to. You not only didn't answer any of the issues, but you totally bummed me out. With advice and encouragement like that, I hope you're not psychiatrist. :D

[reefmanic]

http://www.reefcorner.com/clams.htm


http://members.home.net/kevdone/AF/On_The_Half_Shell.html

Here's some links on clams that might help.


August

[Rovert]

Hey, reefmanic, wow! Great links, thanks.

I read everything, and it looks like the answer to on sand vs. on rock is 'yes'. And 'no'. At least, a definite maybe. Seems people have had success doing it a number of different ways, but I decided to leave the clam on a small, rather flat piece of live rock, and hope it will adhere over the next few days, because that's what they do in the wild. Since I'm leaving for a business trip for the next few days, it will give this little guy a chance to settle in, without my being tempted to move it.

Appreciate everyone's help!

Oh, and AASC - I was just kidding. I see you've only had 2 posts, and I definitely understand the enthusiasm to want to help. Hope you didn't take my ribbing the wrong way.

Regards,
RK

[NaH2Ofreak]

Rovert,

I would say put maximas and corceas(sp) on rocks. Put derasa and gigas on the sand. I can almost gaurantee the blenny is the problem. Hopefully and probably, the clam will get used to the blenny. It will just take time. I currently have a 4" derasa that a tank likes to swim and hover over. The clam draws in everytime. My other derasa clam is used to the tang and dosent draw in anymore. By the way.....BEAUTIFL clam!!!!!!!!!!!!!!!!!

HTH
Dennis

P.S. D. Knop is a pretty respected authority on clams and he reccommends regular additions of phyto plankton. As the clam matures, phyto seems less important. DT's live phto is probaly the best but its too expensive for me. I use tahiatian blend from http://www.brineshrimpdirect.com and it has worked well for me.

[Rovert]

NaH2Ofreak, thanks. I did just put a light layer of sand between the clam and that rock I mentioned, and moved it to a lower current area, out of the main roaming range of the blennie. I'm going to need to get the blennie out of the tank eventually, but I'll just have to wait a while longer until the 55 FO cycles and settles in a bit. Probably have to put up w/ him for at least a month more.

I did buy some DT's and will dose again tonight when I back off to actinic only. You're right - this stuff is pretty expensive, but anything that helps the tank is a good thing.

Regards,
RK

[AASC]

Hey Rovert, me offended ? Not at all, I'll just send you a package of those nice little white molluscs and try and convince you that they are a beneficial symbiont ! :)