cabrego January 12, 2010 January 12, 2010 OK, so I have seen a massive decline in my rotifer population and upon microscopic inspection I have found that there is a significant number of pods (amphipods and probably copepods) in my rotifer culture. can these two critters coexist? Has any experienced this before?
ctenophore January 12, 2010 January 12, 2010 I think you'll probably have to start the rotifer culture over. Bleach the bucket and restart from clean rotifers. Or, you could try saving some of the rotifer water and passing it through 100 micron mesh. That should exclude most of the larger pods, but some little ones might slip through. I suppose you could also just transfer a pipette tip full of rotifers into a bucket of greenwater and hope you don't get any pods. After all, it's super easy to contaminate live phyto with rotifers, maybe you could make that work to your advantage in this case by starting a culture with just a couple individuals.
cabrego January 12, 2010 Author January 12, 2010 After all, it's super easy to contaminate live phyto with rotifers, maybe you could make that work to your advantage in this case by starting a culture with just a couple individuals. What do you mean by your last sentence? I am only culturing rotifers, I think I missed the point. I suppose I could try to build a culture from only a few rotifers, that would be challenging and interesting. As far as seiving goes, I think I would end up letting larva or someting else by, so I think I would be better off starting from scratch or trying to build a culture from what I have...
ctenophore January 12, 2010 January 12, 2010 What do you mean by your last sentence? I am only culturing rotifers, I think I missed the point. I suppose I could try to build a culture from only a few rotifers, that would be challenging and interesting. As far as seiving goes, I think I would end up letting larva or someting else by, so I think I would be better off starting from scratch or trying to build a culture from what I have... Sorry, I meant: for those people who culture live phytoplankton (in the same room with rotifers) there is a constant danger of just a drop of rotifer water getting in the phytoplankton jugs. That's why it's suggested to keep live phytoplankton cultures on a shelf above the rotifers, to prevent accidental contamination. Just a couple of rotifers is all it takes to multiply in a phyto culture and consume it. So, I was suggesting that you could use this phenomenon to your advantage with your non-live algae paste greenwater, possibly starting a new rotifer culture from just a few individual rots dropped in a gallon of greenwater.
dbartco January 12, 2010 January 12, 2010 are they copepods or artemia? If hatching bbs around it is easy to contaminate. Its seems harder to contaminate with copepods. They ususally don't propagate well and I don't know where they could have come from.
davelin315 January 12, 2010 January 12, 2010 are they copepods or artemia? If hatching bbs around it is easy to contaminate. Its seems harder to contaminate with copepods. They ususally don't propagate well and I don't know where they could have come from. Uh oh... this might be my fault... when I was keeping your rots for you I used water out of my tank for the water changes... there could have been zooplankton in the water that got in there if he got them from you...
Jon Lazar January 12, 2010 January 12, 2010 I would continue feeding the copepod/rotifer culture and see if you can sustain it as copepods. Meanwhile, start a second culture of rotifers using new saltwater. I use the "waste" water from my RO/DI for all my non-reef water needs. Fish only quarantine tanks, rotifer water, greenwater, etc. Jon
marinap January 12, 2010 January 12, 2010 I would continue feeding the copepod/rotifer culture and see if you can sustain it as copepods. For larvae feeding purposes calanoid pods such as A.tisbe are useful. Without an ID of the pods in your culture, I would not bother with them. Start from scratch. You do not want unknown pods in your fry tank.
cabrego January 12, 2010 Author January 12, 2010 Hey everyone thanks for all the responses. What I am seeing are definitely a type of pod I still am not 100% sure if it is copepod or amphipod. Yesterday, I was convinced it was amphipod, who knows, maybe tomorrow I will think it is artermia!! I have a massive pod/shrimp population in in my fuge and display tank (especially behind the eggcrate of my foam wall) so I am not terribly interested in culturing pods unless I know I can feed them to my fry. The good news is that there are still rots in the culture just not a whole lot, I hope to seem them bounce back. I will continue to observe under the microscope. by the way I did some digging and found this image online, this is nearly matches 100% of what i saw under the scope. Maybe only a slight variation of this image, any thoughts on what type of pod it is? BTW, these critters move very fast and they are easily visible on the drop of water, for size comparison a rotifer was about the size of the spot on the upper right.
marinap January 12, 2010 January 12, 2010 Edit: For calanoids I meant A.tonsa, not tisbe. Tisbe is on my mind and they made their way into my previous post. Sorry about that. Drain you rotifer culture through a 56 micron filter to get rid of the contaminating organisms or at least decrease their population.
cabrego January 13, 2010 Author January 13, 2010 Edit: For calanoids I meant A.tonsa, not tisbe. Tisbe is on my mind and they made their way into my previous post. Sorry about that. Drain you rotifer culture through a 56 micron filter to get rid of the contaminating organisms or at least decrease their population. INteresting that you mention A.tonsa as I believe that is the picture I posted. The problem I see is that they appear significantly larger than rotifers so I think freshly hatched larva would have major troubles munching on them...
ctenophore January 13, 2010 January 13, 2010 I doubt you are accidentally culturing A. tonsa. I've been doing a lot of reading on them and from what I've found, they do not grow well/easily on phyto paste. marinap, are you culturing Tisbe sp. or A. tonsa?
cabrego January 13, 2010 Author January 13, 2010 (edited) I doubt you are accidentally culturing A. tonsa. I've been doing a lot of reading on them and from what I've found, they do not grow well/easily on phyto paste. marinap, are you culturing Tisbe sp. or A. tonsa? Well, I don't know what it is exactly but the picture I posted is nearly identical to what I see in the microscope. I am by no means a microorganism expert, but I have spent quite some time under the microscope over the last couple of days and I see that little bugger. Does A.tonsa feed on rotifers? by the way I am not feeding phytopaste, I am feeding live very fresh DT's which contains Nannochloropsis oculata, Phaeodactylum tricornutum and Chlorella. Edited January 13, 2010 by cabrego
cabrego January 13, 2010 Author January 13, 2010 http://www.luciopesce.net/copepods/intro.htm Interesting read, these guys look a lot alike! I am going to have to figure out which phylogeny matches what is in my culture.
ctenophore January 13, 2010 January 13, 2010 From what I've read, identifying them yourself is pretty much impossible. Even experts have to send samples of their pods to copepod researchers to really know what species for sure. They do not feed on rotifers, only phytoplankton. It is possible that they are growing on the DTs though. I doubt it matters what species it is though, if they are small, free swimming, and reproduce readily, they could be suitable as larval food. I would try to culture them if you can, because if you can grow a big population of them, they will be much better food than rotifers!
marinap January 13, 2010 January 13, 2010 marinap, are you culturing Tisbe sp. or A. tonsa? Tonsa are indeed difficult. My culture came in contaminated from the vendor. The plan was to feed them Phycopure (has not been tried by anybody yet, but should work). tisbe are self-culturing at the moment, they populated a 10g with one tiny fish that is being fed with spirulina and othomine. Calanoids of the right size are indeed superior to rots as first food for fry of the difficult species. If you guys want to try tonsa again, we can place an order and have three separate cultures going. Could be an interesting experiment.
marinap January 13, 2010 January 13, 2010 (edited) I would try to culture them if you can, because if you can grow a big population of them, they will be much better food than rotifers! Judging from what is said about the size of those pods, they are too big as first food. Edited January 13, 2010 by marinap
cabrego January 13, 2010 Author January 13, 2010 Well, I missed my hatch last night so I am not in dire need for rotifers at the moment. Last night, I went through a few milliliters of the culture and hand picked (using the microscope) some drops of water that contained only rotifers. I placed them in a pint glass with DT's, I must have grabbed around 10 rotifers. Hopefully I will have close to 1000 today
ctenophore January 15, 2010 January 15, 2010 Tonsa are indeed difficult. My culture came in contaminated from the vendor. The plan was to feed them Phycopure (has not been tried by anybody yet, but should work). tisbe are self-culturing at the moment, they populated a 10g with one tiny fish that is being fed with spirulina and othomine. Calanoids of the right size are indeed superior to rots as first food for fry of the difficult species. If you guys want to try tonsa again, we can place an order and have three separate cultures going. Could be an interesting experiment. I'm game for that as soon as I get a decent culturing system set up. Probably by spring so I can keep it in the greenhouse. I found this site detailing a medium scale culture system. I am going to study this and see if I can both downscale it and automate it a bit better.
ctenophore January 15, 2010 January 15, 2010 Judging from what is said about the size of those pods, they are too big as first food. Probably true, but could be great conditioning food for small broodstock. Liopropoma basslets, mandarins, gobies, dottybacks, assessors come to mind
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