Coral Hind October 25, 2010 October 25, 2010 Well all five of my clams spawned to day. I have a 12" squamosa which started it all off. After about 20 minutes of going at it alone the 10" squamosa joined in. The two 4" golden teardrop maximas, and a 1 1/2" blue maxima followed about 30 minutes after that. The event lasted just over two hours and it ended with a very cloudy and smelly tank. I just finished doing a water change and the fish seem fine but the E. quadricolors are not happy all. They are now moving all over and are very deflated. Here is a video of three of the clams.
Jon Lazar October 25, 2010 October 25, 2010 Interesting that you had multiple species involved in the same spawning.
Mando77 October 25, 2010 October 25, 2010 Very cool. What are you feeding to your clams and how often.
Coral Hind October 25, 2010 Author October 25, 2010 Cool. Did you get any pictures? No pictures, just the video. Very cool. What are you feeding to your clams and how often. I do not directly feed them at all. I do have an extremely heavy bio-load and I have zero nitrates with no sand bed at all. So I assume the clams are doing their part at filtering the water.
Coral Hind October 25, 2010 Author October 25, 2010 Very nice. Those are happy clams. They looked really tired and stressed afterwards. The constant pumping action must be very hard on them. Even after nothing else was going out of them they still kept pumping. Interesting that you had multiple species involved in the same spawning. Yes, this also surprised me. I didn't know they would do that ethier. I was really surprised to see the little blue clam trying to join in as it is barely an 1 1/2".
Coral Hind October 25, 2010 Author October 25, 2010 I'll also add that the first half of the event seemed to be the sperm release followed by the release of the eggs. The eggs looked almost like very small micro bubbles in the tank, millions of them.
Valeria October 25, 2010 October 25, 2010 Dave, Are those the ones you got from me? If so that is twice in ...3-4 months
Coral Hind October 25, 2010 Author October 25, 2010 Some are from you and some are existing ones. I also have two crocea that didn't join in, just the squamosas and the maximas.
Origami October 25, 2010 October 25, 2010 So, do you dim the lights - maybe play a little soft music?
OUsnakebyte October 26, 2010 October 26, 2010 I sure hope you are taking the opportunity to rear the larvae!!!
dano October 26, 2010 October 26, 2010 Wow!! Very cool and I can't wait to show my boys the video. Congrats and good work!
Chad October 26, 2010 October 26, 2010 I sure hope you are taking the opportunity to rear the larvae!!! Haha, I think it is a great big yummy dinner for the corals and workout for the skimmer!
Coral Hind October 26, 2010 Author October 26, 2010 Is that the big clam I gave you?? Looks good. Yours didn't join in on the party. I sure hope you are taking the opportunity to rear the larvae!!! If it were to happen again I might try to collect them but I was not prepared to at the time. I was more focused on getting the sump and skimmer to stop overflowing, mixing saltwater, skimming the masses of sperm off the top of the water,and getting the pH which was dropping very fast back up to where it should have been. What suggestion do you have on rearing the larvae for next time?
OUsnakebyte October 26, 2010 October 26, 2010 (edited) If it were to happen again I might try to collect them but I was not prepared to at the time. I was more focused on getting the sump and skimmer to stop overflowing, mixing saltwater, skimming the masses of sperm off the top of the water,and getting the pH which was dropping very fast back up to where it should have been. What suggestion do you have on rearing the larvae for next time? Yeah, I know the feeling when you see the cloudiness of a tank full of spawn - and the work ahead of you... Well, there are a couple of options. Typically with broadcast spawning species, sperm concentration matters - not enough sperm and you won't get good fertilization; too much sperm and you risk polyspermy (more than one spem fertilizing an egg = death of the larvae). And guess what, it's species specific, at least with corals. I've never bred nor reared larvae of any clams, so looking through some literature, b/c they are farmed and there should be information on them, would be a first start. With that disclaimer... Obviously, you want to mix like with like - squamosa with squamosa, maxima with maxima, etc. If you can catch them in the act (like it looks like you did), I would move each clam to an individual tank/bucket (like 5.5 gallon tanks). It sounds like they are sequential broadcasters, releasing sperm first, then eggs, which in the wild would decrease the chances of self-fertilization. Limiting the amount of water they are in is key, b/c it is easier to dilute sperm concentration than increase it - just add water. When they start releasing eggs, you'll need to start pipetting out the eggs and moving them to the other clam's sperm in the other tank/bucket - now you are doing specific crosses. At least in corals (and assuming sperm concentration is optimal), fertilization can/will happen within an hour. If you want to leave the eggs in for two hours, probably okay. If you went this route, then you need to be sure to rinse the eggs. When that sperm starts dying off, it will foul the water and kill your larvae. Gently pipette out the eggs and transfer them to clean water, remembering to keep the species separate. Don't forget to put your adults back in the display... But, what if you come home and they have all already started smokin' their cigs...? Well, now you just have to hope that nature can take it's course in your tank. You probably have overflows which means much of the spawn has found it's way to your sump and is gone. If you have any left, shut off all you pumps/powerheads and wait. I know it's hard watching all that stuff pollute your tank, but give it at least an hour if you can. I'm sure you can occupy your time mixing up new water, etc. If the eggs are positively buoyant, it will be easiest to get them out just by using a cup to skim them off the surface. If they are neutrally or negatively buoyant, then you'll need to pipette or use a baster to get them out. Whatever you do, BE GENTLE! Most developing larvae are very delicate for the first day or so, and you can tear the membranes very easily. Unfertilized eggs will typically crumble apart in 24 hours, maybe less. So, lets's say you now are fortunate enough to have fertilized eggs - what in the heck are you going to do with them? Again, you have options. The least amount of work will be to create a holding tank/cup/bucket/whatever plastic basin you can come up with, with some micron mesh glued on holes you have cut/drilled in the sides - small enough that the eggs can't fit through, so it doesn't have to be 10 micron or anything. 100 micron would probably be fine. Basically, this keeps you from having to do water changes. Add in VERY GENTLE air bubbling for the first day at least. If the developing larvae cram together, they can fuse. The other option is to just float a small tank, say 5.5 gallons, in your display and change the water once a day. You should add the gentle air bubbler here too and try to keep the eggs from binding and clumping together. After the first 24 hours, you can increase the vigor of the bubbling, just don't bash them around. You can also gently stir the eggs to separate them. I recommend stirring every 1/2 hour to hour or so. You are in for a long night. Now, you wait. Access to a low-power dissecting scope is a REALLY big help, b/c you can see cell division start to happen within the first few hours - it's amazingly fast - then blastula, gastrulation, etc., etc. It's really very cool. With this, you can keep tabs on how the larvae are developing and take pictures through the occular to document growth. Eventually, they will become ciliated, start swimming and want to settle, and here the story can really get species specific. I have no idea what the settlement cues for clams are, but I'm sure it's been studied. But access to that information will be key, as will information on how they acquire zoox, initial feeding (probably phyto, I guess). Ideally, if you get settlement, you'll have a dedicated grow-out tank for the larvae. I would not put them in an established reef, though you could plumb than tank into your existing reef to help with water quality. Of course, the above is based on my experience with corals, but I did have two different species of Pacific Northwest anemones spawn back in May, and I did both the methods I described above, and it worked. I have juveniles of both species growing here at work. Yes, it was an exhausting week. Cheers Mike Edited October 26, 2010 by OUsnakebyte
Coral Hind October 26, 2010 Author October 26, 2010 Mike, Great info! I did a lot of reading today at work and it is pretty much in line with what you wrote. I think if it happens again I will not be so freaked out that I will try to catch what I can in an attemp to raise them. Thanks!
DaveS December 1, 2010 December 1, 2010 So I'm looking at my tank before settling in for the night and guess what- my Tridacna clam is getting busy! I got a little video with my phone that I'll post up later. Guess we got a few frisky clams in WAMAS!
DaveS December 1, 2010 December 1, 2010 Yup just one. Too bad, I'd love to try raising them, especially with the great instructions from Mike.
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