Feeding your clam....
- Thread starter REDDAWG43
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homer1475
New member
I feed my clams light for about 12 hours a day.
When I first got my first clam I bought into the whole idea that it needed to be fed every day. All I managed to do was p*ss it off and have it close up when I was trying to feed it. Stopped all that and just left it alone in a low flow, high light area. Its easily tripled in size in just a few short months.
When I first got my first clam I bought into the whole idea that it needed to be fed every day. All I managed to do was p*ss it off and have it close up when I was trying to feed it. Stopped all that and just left it alone in a low flow, high light area. Its easily tripled in size in just a few short months.
jd371
New member
^This, and the small particles of food they filter out of the water column when I feed my fish.
laga77
New member
Clams do not need to be fed. They can absorb what they need from the water column. http://www.advancedaquarist.com/2010/7/inverts
AquaTDV
Member
How do we know that there isn't a dietary shift as the clam ages? As humans our dietary needs shift as we age. Why not other long lived creatures? Especially now that we are using such efficient ways of removing organics, through both biological and mechanical means. Our tanks have the potential to be "cleaner" than they have ever been. You can read about sudden clam death for unknown reasons. Perhaps there is a link. Maybe we should try and do a better job of mirroring the ocean environment when it comes to clams. Especially since they have an inexhaustible amount of food available to them within the ocean. There have been studies on different types of Tridacnae stomach, and they find that not only do clams take in food, but they will show a preference for the type of food they consume. Could this be because of dietary needs? I don't know the answer but I've been keeping clams for 20+ years, and this "Do not feed your clam" concept is very contrary to what happens in their natural environment. Just a thought...
MondoBongo
Obligate Feeder Obsessed
with the exception of T. gigas, this goes against what i've read.
for the other species of Traidacna, everything i've been able to find is that their primary source of carbon intake is from the zoox. they will absorb things directly from the water such as NO3 and PO4, but they don't really filter feed all that much.
i'd be curious to see the write ups on food preferences that you're talking about. the only thing i've seen in that general area is size preferences dictated by the structures that they "digest" with. i know they're capable of taking in zoox through filtering, but i don't believe they "eat" those.
AquaTDV
Member
Thank you for your thought full response.
The link I have saved for the study citing food preferences is no longer available. Looks like it will need to be purchased now. I think I printed a copy at home I will look tonight.
http://research.ju.edu.jo/journals/DirasatSci/article/viewFile/121/119
Here is some more research about feeding, and how it would benefit our Tridacna friends.
https://www.researchgate.net/public..._and_supplemental_feeding_under_acidification
I have had many clams for over a decade and never fed them anything that they did not get from the pretty clean SPS tankwater or Metal Halide.
Back when they first started selling 1" maximas... like early 2000s, I bought into the "gotta feed them" and everybody was using the tall one in the white bottle and even made a lot of my own with culture from Florida Aqua. After a few died, I got 4 more on the cheap... put two into a Tupperware that I would lift out and feed some photo nearly every day and had two that just were in the tank. The two in the Tupperware would indeed filter that green water clean in a few minutes, but died - the other two were with me for a long time. I imagine the death was from all of the commotion and movement and nearly certainly not from the phyto, but that it not the point... the point is that the two that got nothing except for light and whatever they wanted from the tank were fine.
Back when they first started selling 1" maximas... like early 2000s, I bought into the "gotta feed them" and everybody was using the tall one in the white bottle and even made a lot of my own with culture from Florida Aqua. After a few died, I got 4 more on the cheap... put two into a Tupperware that I would lift out and feed some photo nearly every day and had two that just were in the tank. The two in the Tupperware would indeed filter that green water clean in a few minutes, but died - the other two were with me for a long time. I imagine the death was from all of the commotion and movement and nearly certainly not from the phyto, but that it not the point... the point is that the two that got nothing except for light and whatever they wanted from the tank were fine.
MondoBongo
Obligate Feeder Obsessed
the academic paywall is a cruel mistress.
thank you for the links, i'll check them out.
That study says that they probably grow faster if you fed them, but that you did not need to. There were very low mortality rates on either side and they attributed some of that to the substrate - more deresa survived not being fed than fed (probably just an anomaly).
I don't know of anybody who can set up a raceway just like they had it with the specific purpose of feeding clams by using seawater. In the end, what did we learn about clams in a mixed reef tank? This was a nice academic study, but not much else IMO.
What about Fatherree who specifically studied clams in the aquarium:
http://www.advancedaquarist.com/2010/7/inverts
I don't know of anybody who can set up a raceway just like they had it with the specific purpose of feeding clams by using seawater. In the end, what did we learn about clams in a mixed reef tank? This was a nice academic study, but not much else IMO.
What about Fatherree who specifically studied clams in the aquarium:
http://www.advancedaquarist.com/2010/7/inverts
AquaTDV
Member
Your right. Our understanding of giant clams has evolved since the late 90's early 2000's. I never understood the rationale behind removing a clam from a tank to stick it in phyto saturated saltwater. The stress the clam would be under would negate any positive results you might see from your feeding.
AquaTDV
Member
This is directly from that study in 2012:
"Phytoplankton Feeding
Most hobby aquarists accept logical arguments for the importance of phytoplankton feeding like those of Shimek (2009)who states: "˜Natural selection acts to minimize unnecessary costs. If clams from Tridacna or Hippopus species didn't need to feed, the feeding structures would be eliminated. There are a number of clams that live totally on the byproducts of symbiotic bacteria living on their gills. These clams are totally gutless. The fact that every Tridacna and Hippopus individual has a good and functional
apparatus ABSOLUTELY PROVES that they need to feed.' To date, however, experimental evidence of the impacts of phytoplankton supplementation on the growth of cultured tridacnid clams is limited and the specific role of phytoplankton feeding with tridacnids is still poorly understood (Delbeek & Sprung,1994; Fatherree, 2006)."
Academic paper: Growth of cultured giant clams (Tridacna spp.) in low pH, high-nutrient seawater: Species-specific effects of substrate and supplemental feeding under acidification. Available from: https://www.researchgate.net/public..._and_supplemental_feeding_under_acidification [accessed Apr 3, 2017].
I've read Fatherree's article many times, and it was written in 2010. Since then our filtration systems are far more efficient than the days of the air stones and early venturi skimmers. Not to mention biopellets and other low NO3 applications. Even our GFO has become high capacity, so we can get our PO4 to <.01 levels. Maybe its time to take another look at feeding these animals?
I've personally seen positive results from it.
How are you going to do it? You going to pour 64 ounces of phyto in there, watch it get watered down and filtered out to where the clam gets hardly anything? This is still all mostly academic and not all that feasible.
Saying that they have gills and ABSOULTELY need to be fed is as unimporant as saying that they have symbiotic algae and they ABSOULTELY do NOT need to be fed. The answer lies somewhere in the middle. I think that you are underestimating their ability to filter what is in the water already, which can be quite significant with larger clams where I have personally struggled to keep any amount of detectable N and P only to see them rise once I rehomed the clam. Just because you don't put stuff in the water for them to eat does not mean that they are not eating anything. BTW - I don't advocate a sterile reef tank and we certainly see many deaths of clams in new tanks.
You aren't suggesting that people acidify their tanks for the benefit of their clams, are you? If not, then what does this study matter?
Who was using air stone skimmers in 2010? That brought me back to the early 1990s. BTW - some of those were pretty good in small tanks.
I think that using LED with their lack of spectrum over 600, or just lack of general power, to care for clams is far more dangerous than not feeding them.
Saying that they have gills and ABSOULTELY need to be fed is as unimporant as saying that they have symbiotic algae and they ABSOULTELY do NOT need to be fed. The answer lies somewhere in the middle. I think that you are underestimating their ability to filter what is in the water already, which can be quite significant with larger clams where I have personally struggled to keep any amount of detectable N and P only to see them rise once I rehomed the clam. Just because you don't put stuff in the water for them to eat does not mean that they are not eating anything. BTW - I don't advocate a sterile reef tank and we certainly see many deaths of clams in new tanks.
You aren't suggesting that people acidify their tanks for the benefit of their clams, are you? If not, then what does this study matter?
Who was using air stone skimmers in 2010? That brought me back to the early 1990s. BTW - some of those were pretty good in small tanks.
I think that using LED with their lack of spectrum over 600, or just lack of general power, to care for clams is far more dangerous than not feeding them.
AquaTDV
Member
http://journals.ju.edu.jo/old/index.php/DirasatSci/article/viewFile/121/119
Here is the study that discussed in greater detail the Nutrition of Giant Clams. Sorry it took so long I ran across it by accident on an older disc I keep my nerdy aquarium stuff on.
This is a quote from the intro:
"The giant clams feed daily or at least every second
day, food particles are selected according to clams needs
and the animal usually discriminate between the
planktonic and non planktonic parts which are then
expelled as clumps by contraction of the shell (Daniel
1996; Klumpp et al., 1992). Appropriate size for
ingestion ranges between 1 and 15 µm for filter feeding
and 10 to 100 µm for the grazers (Webb et al., 1983;
Kawamara et al., 1998). Clams are well adapted to
handling resuspended silt in high concentration and may
sort algae cell from inorganic particles prior to ingestion
(Jeffery et al., 1992). Clam of 0.3 g dry meat weights
continue to filter even if seawater silt particles densities
exceed 300 mg.l-1 (Eaton 1981). Microalgae such as
Nannochloropsis oculata, Isochrysis galbana and
Tetraselmis suecica are microscopic organisms with plant
- like properties, and are an important component of
aquatic ecosystems because they provide food for a large
population of aquatic animals (Brown and Robert 2002;
Tafi 2002). In particular, they are of great importance to
the commercial culture of bivalve molluscs larvae,
Juveniles, and adults (Kawamura and Nicholson 1998).
They are utilized in aquaculture as live food for all
growth stages of oysters, scallops, clams, and mussels
(Jeffrey and Brown, 1992; Horstmann 1965; Pruder 1986;
Webb and Chu 1993). "
The study goes into much greater about the grazing rates of different
types of clams at all stages of life.