dense copepod culture question

[TheStrangler]

Hey friends, I'm doing a bit of research to begin a study on producing dense enough copepod cultures to feed fish fry. As I understand it, providing enough food for dense cultures while maintaining water parameters is the main problem, at least at the hobbyist scale. Mechanical filtration isn't ideal, and biological filtration increases the risk of contamination. Suppliers offers foods with ammonia binders to decrease the problem, but that still ultimately means that the problem exists and a band aid is being applied. While water changes are unavoidable, my aim is to make them primarily less urgent, and ideally less frequent. Rather than substantial water changes over short periods of time, I'm looking for ways to deal with organic waste that require less effort and allow for more stability as you provide enough food to create a dense culture. I intend to use 9 cultures of the same pods from the same source. Three will be a control group, three will start with dry rock, bottled bacteria, and clean macroalgae. The final three will use Seachem purigen or a similar product.

I'm sure I'm not the first to try this and just wanted to ask the community if they've happened across anyone else who has tried chemical filtering? I did a few searches and didn't find what I was looking for, so if anyone has any experience I'd love to hear it. Nothing saves time like, Yeah I tried it, crashed the culture because X.

Thanks!

 

[ludnix]

I am curious how you are going to provide clean macroalgae. Maybe a dip of some sort that is lethal to crusteacea followed by a long soak in new saltwater?

Looking forward to your findings!

 

[TheStrangler]

First thought was to start with the Algaebarn clean macro. While I imagine they do a pretty good job, I've got a pretty strong UV sterilizer, and I'm sure I could come up with some chemical dip to make sure the algae is sterile.

 

[ichthyogeek]

So, I think the first question I have is: what copepod genus/species are you going to try and culture? If you're doing it for fish fry, then a lot of the ones I've found that are commercially available and viable for larviculture are pelagic calanoid and cyclopoid copepods, not the "easier" benthic harpacticoid species. Think Parvocalanus and Pseudodiaptomus vs. Tisbe and Tigriopus. That's not to say that you couldn't feed fish fry with Tisbe and Tigriopus, I know of at least one member (ThRoewer) that feeds Tigs to his clownfish larvae. But if you're looking at raising angelfish larvae, etc, then you're looking at eggs/N1 stages for pods like Parvo, Euterpina, and also ciliates.

That also ultimately also determines what you're feeding the culture. Apocyclops is able to thrive off of algae pastes. Parvo loooooves Isochrysis. And this will determine changes in water quality as live microalgae is consumed and waste produced, or if dead microalgae is consumed and decomposes along with waste produced.

Are you a grad student? Or just doing this for fun?

 

[Crustaceon]

First thought was to start with the Algaebarn clean macro. While I imagine they do a pretty good job, I've got a pretty strong UV sterilizer, and I'm sure I could come up with some chemical dip to make sure the algae is sterile.

I’ll bet you could just freshwater dip the macro algae for five minutes and get the same results.

 

[TheStrangler]

So, I think the first question I have is: what copepod genus/species are you going to try and culture? If you're doing it for fish fry, then a lot of the ones I've found that are commercially available and viable for larviculture are pelagic calanoid and cyclopoid copepods, not the "easier" benthic harpacticoid species. Think Parvocalanus and Pseudodiaptomus vs. Tisbe and Tigriopus. That's not to say that you couldn't feed fish fry with Tisbe and Tigriopus, I know of at least one member (ThRoewer) that feeds Tigs to his clownfish larvae. But if you're looking at raising angelfish larvae, etc, then you're looking at eggs/N1 stages for pods like Parvo, Euterpina, and also ciliates.

That also ultimately also determines what you're feeding the culture. Apocyclops is able to thrive off of algae pastes. Parvo loooooves Isochrysis. And this will determine changes in water quality as live microalgae is consumed and waste produced, or if dead microalgae is consumed and decomposes along with waste produced.

Are you a grad student? Or just doing this for fun?

Due to availability and consistency I had planned on starting with Tigriopus. I'd like to throw in an additional sets of variables around temperature and maximum possible feeding of the cultures, ramping up feeding every time period after its established that the bioload is still stable from the previous but I'd never be able to come to any scientific conclusions if I've got that many variables. Ideally this would go in a number of phases, the first on trying to find a more stable culturing condition than the traditional method. Its reasonable to guess that if the culture conditions are more stable for easily available Tigriopus pods, I should expect similar results for all cultures barring cannibalism of certain species, etc. Once I find the most sustainable biohandling method, I'd then start experimenting on culture densities as they're directly related to availability of food and water condition. More food should mean greater culture densities, assuming the findings from stage one allow more food to be present without inevitably causing a crash.

I'm not a grad student, but I've got access to a lab to make sure I do everything repeatably to confirm any findings I might end up with. I've already established bias by going into the study with a goal in mind, but if I get any findings I can pass the info off to others to see if they find the same results.

I’ll bet you could just freshwater dip the macro algae for five minutes and get the same results.

I actually tried that with the chaeto I ordered for my display tank, and it helped but not completely. I had a few dead amphipods in the clump after dipping for a while, probably 10+ minutes, but some were still alive. A longer dip may work?

 

[Crustaceon]

Due to availability and consistency I had planned on starting with Tigriopus. I'd like to throw in an additional sets of variables around temperature and maximum possible feeding of the cultures, ramping up feeding every time period after its established that the bioload is still stable from the previous but I'd never be able to come to any scientific conclusions if I've got that many variables. Ideally this would go in a number of phases, the first on trying to find a more stable culturing condition than the traditional method. Its reasonable to guess that if the culture conditions are more stable for easily available Tigriopus pods, I should expect similar results for all cultures barring cannibalism of certain species, etc. Once I find the most sustainable biohandling method, I'd then start experimenting on culture densities as they're directly related to availability of food and water condition. More food should mean greater culture densities, assuming the findings from stage one allow more food to be present without inevitably causing a crash.

I'm not a grad student, but I've got access to a lab to make sure I do everything repeatably to confirm any findings I might end up with. I've already established bias by going into the study with a goal in mind, but if I get any findings I can pass the info off to others to see if they find the same results.



I actually tried that with the chaeto I ordered for my display tank, and it helped but not completely. I had a few dead amphipods in the clump after dipping for a while, probably 10+ minutes, but some were still alive. A longer dip may work?

Probably. You’ll also want to swish the macro around a little. I would’t be surprised if there was a saltwater boundary layer within the clump those amphipods found and were able to survive in.

 

[TheStrangler]

Good thought. I'll likely do a 1 hr freshwater dip in a bucket with a powerhead or something even if I buy clean macroalgae. I can take a peek at a sample under a microscope to figure out if its actually clean when done.