noob wants to spawn bluegill

[Stalemate]

After losing 1/4 of my initial bluegill introduction to my system I have a feeling that I should try to propigate the colony.   They are in a 350 gallon rubbermaid circular tank which has no media at the bottom.  As I understand it bluegills want some gravel to breed but having no gravel in the tank makes the solids easier to flush through the growbeds.  Can I add something like a litter box of gravek with a "hey breed here" sign in a corner of the tank?  Or do I need to get a clue if I'm expecting these fish to spawn?

[George]

http://aquaponicscommunity.com/group/bluegillorbreamgrowers/forum/t...

See the link above to a forum thread which contains a link to a download - some breeding info there.  You've got a circular tank with a corner?  Just kidding.  It is news to me that Rubbermaid makes a circular tank - sounds interesting.  Are your bluegill sexually mature, do you think?  If not, then you've got time to think about it.  I think your idea might be ok about using part of the tank for a spawning bed - wouldn't hurt to try it but I expect you'll need to cover the entire bottom and then maybe they'll fan out a bed or two.  I wouldn't be concerned about covering the entire bottom and you can always remove it later if you wish.  If you dump gravel on part of the bottom it will likely get scattered.  My plan is to use a separate tank so I can control which ones breed and I'll probably use small gravel and sand.  Most of my bluegill have genes I don't particularly want to perpetuate but it appears that I have a few that are spawn-worthy.  Another thought about using the same tank is by that time your older fish will be big enough to eat the fry.  Of course, that's the way it works in the wild.  Good luck. 

[George]

I can't remember where I saw it but spawning pans with gravel are used for bluegill so you could put a pan or two in your tank - you could use large, stainless or plastic mixing bowls.  Good luck.

[Keith Rowan]

male bg are territorial.. i think natural spacing in ponds was observed at around 18" to 24", but "bluegill" is a pretty general term..(lots of hybrids as well)

i'd approach it similar to other fish.. depending on the size of the tank, i'd have 1 male for every 3 or 4 females..

you could try to induce spawing by manipulating their light cycle

[George]

One male to two females was recommended in one of the studies cited in the bluegill group.  One such successful breeding should result in many more bluegill than I will need - can't remember how many hundreds but even after culling I hope to have a large surplus.

[Jon Parr]

Yes, gravel pans can be used to spawn bluegill, and they have been known to spawn in an ordinary aquarium. But be warned, spawning is not the hard part. Bluegill fry are larval feeders, and require copious quantities of live zooplankton for the first 2-3 weeks of their lives. After that, they can be trained to take feed. That is why most all successful fingering production is in outdoor ponds, during the natural season.

[George]

Phytoplankton too.  I don't think that will be much different in a tank VS a pond but we shall see.

Jon Parr said:

But be warned, spawning is not the hard part. Bluegill fry are larval feeders, and require copious quantities of live zooplankton for the first 2-3 weeks of their lives.

[Keith Rowan]

greenwater cultures are pretty easy to start and maintain.. i have several 5 gallon buckets going in my basement under a single 4' shoplight flourescent fixture..

if you do a culture outdoors, you should add a few minnows to control mosquitos

[Jon Parr]

Phytoplankton is required to rear the zooplankton, yes. Minnows will feast on the bluegill larva and fry, so I wouldn't advise them in a controlled plankton tank or pond. Commercially, bluegill are sometimes spawned in tanks, as this allows selective traits to be kept, and the eggs are moved to a separate tank (or adults are removed), until they hatch and use up their yolk sacs. Then they are brought to plankton tanks. The plankton tanks start with clean water and fertilizer to stimulate an algae bloom, which then stimulates a zooplankton bloom. Timing is critical, because this zooplankton bloom stimulates bigger critters that also eat larval fish, which are to be minimized for obvious reasons. By the time Mosquito larva would hatch, the bluegill fingerlings will be eating them too. In a natural outdoor setting, all of this happens continually, so diversity is great, meaning minnows an frogs and plenty of plants and reeds for hiding spots.

[George]

Would you elaborate on the bigger critters?

Jon Parr said:

Timing is critical, because this zooplankton bloom stimulates bigger critters that also eat larval fish,

[Jon Parr]

Beetles, water boatmen, dragon fly larva, hydra, etc. It's a ruthless food chain, and the "bigger critters" can fly in, so pretty tough to keep out.

[George]

Thanks Jon.  I'll experiment with establishing plankton prior to setting up the spawning.  It still doesn't sound  difficult but I've been wrong before.

[Tommy D]

Thanks, I been learning about breeding blue gill. It's something I will try.