24 replies to this topic

[az9]

As a small scale producer of bluegill, yellow perch, black crappie, tilapia, trout, and in the past smallmouth bass, I have hatched all my fish in small 1/10 acre ponds, and then brought the fingerlings inside to circular approximately 160 gallon tanks to feed train with the exception of the trout. It's involves filling and fertilizing a pond, and allowing the broodfish to do their thing. Then come back and seine the fry or fingerlings out and feed train indoors in small recirculating tanks. 

 

However, for the few hundred fish of each species I need annually  for my small niche market providing frozen trophy size fish for fellow taxidermists all over the country, the ponds are labor intensive with the seining, draining, and refilling. Not to mention the use of lots of water and the pumping costs both well water and dewatering. I'd rather use the ponds for holding ponds for broodfish. Would like to consider spawning  bluegills, crappies, and yellow perch egg strands in an aquarium indoors. I don't' think I'll have a problem with the spawning and egg hatching, but as many of you know the centrarchid and percid larvae need live feed initially vs. for instance tilapia that will feed on fine artificial feed from the get go. 

 

Are live brine shrimp small enough for larvae bluegill and crappie? I assume the fish fry initially have a yolks sack right?  I've never hatched brine shrimp, but it appears relatively easy from what I've read. If so, it seems it wouldn't be difficult to take the fish larvae from the brine shrimp to fry powder size artificial feed once they are large enough to ingest the fry powder? I've had pretty good luck training pond hatched centarchids and percid fingerling species to accept artificial feed.  

 

Look forward to hearing feedback from folks here with experience with this. No doubt centrarchid has lots of experience with this! Things like optimum aquarium size and substrate would be helpful too. 

 

Thanks! 

[az9]

Looks like this pub does a good job of answering my questions:

 

http://extension.missouri.edu/p/G9473

 

Looks like centrarchid had a hand in this as it's his college? 

[centrarchid]

Paper above deals more with pond rearing and we did try to teach Hicks how to rear indoors.  Brine shrimp are our default first feed for Lepomis and Micropterus.  Need smaller for the crappie.  We have Bluegill being bred almost continuously.  Will be doing Bantams and possibly Dollars with a high school in the coming weeks assuming incubator does not catch on fire again.

[gerald]

Yes, hatching brine shrimp is easy, but can be labor intensive especially when egg cysts and nauplii don't separate well (depends on the type and quality of eggs).  A dark colored tub (blue, black, brown) will help the fry eat more nauplii and less cysts.  Also, could you reserve a few small ponds specifically for small plankton culture (rotifers, large ciliates, small copepods, etc)?  With good timing, you could harvest with a plankton net to provide food for any fry that aren't ready to take BS. 

[az9]

Paper above deals more with pond rearing and we did try to teach Hicks how to rear indoors.  Brine shrimp are our default first feed for Lepomis and Micropterus.  Need smaller for the crappie.  We have Bluegill being bred almost continuously.  Will be doing Bantams and possibly Dollars with a high school in the coming weeks assuming incubator does not catch on fire again.

 

Thanks. 

 

Catch on fire?! What's that all about? 

[az9]

Yes, hatching brine shrimp is easy, but can be labor intensive especially when egg cysts and nauplii don't separate well (depends on the type and quality of eggs).  A dark colored tub (blue, black, brown) will help the fry eat more nauplii and less cysts.  Also, could you reserve a few small ponds specifically for small plankton culture (rotifers, large ciliates, small copepods, etc)?  With good timing, you could harvest with a plankton net to provide food for any fry that aren't ready to take BS. 

 

Thanks Gerald. Makes sense to me. 

 

What's the deal with the fish eating the cysts? 

 

I was thinking of culturing them and setting up a unit where the nauplii naturally end up in the aquarium? 

[gerald]

BS cysts (egg shells) are indigestible and can kill small fry, especially perch.  Jeff Hinshaw experimented with this at NCSU in the 80's and wrote some papers on prey contrast effects on survival and growth of perch post-larvae.  In light-colored containers he found they ate too many BS cysts and had poor survival.

 

Not sure how hard it would be to set up a continuous BS culture that would trap and transfer newborn nauplii into fish aquariums, but it sounds pretty tricky to me, with maintaining algae cultures and whatever else is needed.  Also, you'll need LOTS of fresh-hatched nauplii within a short period to feed fry, so hatching BS eggs as you need them may be more practical. 

[centrarchid]

Incubator for chicken eggs caught fire.  Started by failure of heating element.

 

 

We use a battery of BS hatchers armed and harvested at 6-h intervals.  Separating cysts from nauplii not difficult.  You can get by with two hatchers at 12-h intervals and still get decent growth.  When a single unit used with harvests every 24 hours, growth will not be ideal.  

 

Our feeding protocol when pushing it involves BS no more than 6 hours post-harvest.  Twelve hour old OK but growth not best for larvae.

[az9]

Centrarchid,

 

Can you recommend a source for the BS hatchers or are they DIY? 

[centrarchid]

Brine Shrimp Direct.  We buy it by the case.

[az9]

How's your luck with the high schools? I set up for high schools on my own dime and except for one they have been a disappointment. 

[az9]

Centrarchid,

 

One more question: Since you said BS may be too big for crappie larvae what do you suggest for them? 

[centrarchid]

Centrarchid,

 

One more question: Since you said BS may be too big for crappie larvae what do you suggest for them? 

Rotifers for the first few days, followed by freshly hatched BS.  The 12-h stuff will not due during the first several days of feeding with BS.  Rotifers themselves must be enriched / fed immediately prior to feeding out to crappie larvae.

[centrarchid]

Centrarchid,

 

One more question: Since you said BS may be too big for crappie larvae what do you suggest for them? 

I have worked with a lot of schools at this point.  About one in five seems to click and the successful most go through some failures without loosing resolve.  Very critical is the instructor although admin must also be supportive.  All teachers I have worked with are seriously overextended.  Current major effort involves one day per week at location 2.5 hours away from my campus.  The school has two instructors and where are partnered on several projects\; aquaculture, chickens, beekeeping, insect culture, composting, vermiculture, and aquatic mesocosms.  Several of those geared to have science fair projects.  Not all conducive to classroom science.

[gerald]

I refrigerate fresh-hatched BS in a shallow container immediately after harvest.  That maintains their small size and presumably their nutritional content too, since they don't molt in the fridge.  This way I can start a new batch every 3 days.  But I'm using only a 1/2 teasp of eggs per hatch, not cups like James is probably using.

[swampfish]

In my very small scale brine shrimp hatching utilizing 2 liter soda bottles, I buy only high hatching percentage cysts, usually 90% or so, which cost more. Empty cyst coverings float and so do many unhatched cysts. The nauplii are attracted to light, which can be used to separate from unhatched cysts. The nauplii can then be siphoned out. I use a bottom light source and drain them from the bottom of the hatching container.

 

Phil Nixon

[az9]

Rotifers for the first few days, followed by freshly hatched BS.  The 12-h stuff will not due during the first several days of feeding with BS.  Rotifers themselves must be enriched / fed immediately prior to feeding out to crappie larvae.

 

Thank you!

[az9]

I have worked with a lot of schools at this point.  About one in five seems to click and the successful most go through some failures without loosing resolve.  Very critical is the instructor although admin must also be supportive.  All teachers I have worked with are seriously overextended.  Current major effort involves one day per week at location 2.5 hours away from my campus.  The school has two instructors and where are partnered on several projects\; aquaculture, chickens, beekeeping, insect culture, composting, vermiculture, and aquatic mesocosms.  Several of those geared to have science fair projects.  Not all conducive to classroom science.

 

I agree. Here they are so geared to teaching for tests and mandates by politicians they are ham stringed when it comes to flexibility. It's a shame as aquaculture involves several scientific disciplines and can make science interesting and fun. If a teacher can show how science applies in real life they can make it much more interesting. 

 

My main problem is getting them to cycle their biofilters in in coordination with my schedule when fish are ready and I need to get them out of my tanks. For the life of me I  can't understand why cycling a biofilter in warm water has to take several months! Only one teacher does it in a few weeks. One was not ready until January! 

 

Don't even get me started on administrators. I had one that failed to understand whey a GFCI was important! I've never seen the administrators for 3 out of 4 schools. 

[az9]

In my very small scale brine shrimp hatching utilizing 2 liter soda bottles, I buy only high hatching percentage cysts, usually 90% or so, which cost more. Empty cyst coverings float and so do many unhatched cysts. The nauplii are attracted to light, which can be used to separate from unhatched cysts. The nauplii can then be siphoned out. I use a bottom light source and drain them from the bottom of the hatching container.

 

Phil Nixon

 

Thanks Phil. 

[centrarchid]

 

I agree. Here they are so geared to teaching for tests and mandates by politicians they are ham stringed when it comes to flexibility. It's a shame as aquaculture involves several scientific disciplines and can make science interesting and fun. If a teacher can show how science applies in real life they can make it much more interesting. 

 

My main problem is getting them to cycle their biofilters in in coordination with my schedule when fish are ready and I need to get them out of my tanks. For the life of me I  can't understand why cycling a biofilter in warm water has to take several months! Only one teacher does it in a few weeks. One was not ready until January! 

 

Don't even get me started on administrators. I had one that failed to understand whey a GFCI was important! I've never seen the administrators for 3 out of 4 schools. 

I always have a couple aquariums outfitted with a cartridge filter where the fish are fed heavily.  When a school needs to cycle a tank, we send them home with a dirty cartridge or two and have them clean the cartridges in water of the system to be cycled.   Cycling usually realized within days after that.  Most water quality failures due not knowing how to feed.  Many times we bring in instructor and sometimes instructor plus students to learn how to feed.  That usually done over the weekend where guest help me and students all day long.

 

Electrical issues here not normally a problem here although school with older greenhouses is going to be a problem since no protections.