NANFA-- Spawning Difficult Fish Outdoors & New Method for Growing

Jeffrey Fullerton (
Fri, 28 Feb 2003 21:43:53 -0500

> Date: Fri, 28 Feb 2003 07:39:15 EST
> From:
> Subject: NANFA--breeding fish
> I accelerated the light and temperature on my swamp darters.
> They started
> breeding Feb. 9 and hatching by the 18th. The fry are now eating
> baby brine
> shrimp and growing well. The parents are still laying eggs
> regularly and I am
> gathering and counting. At the same time my bluespotted sunfish
> started
> spawning I am having a hard time keeping any of them alive, but
> the parents
> keep going.
Trouble breeding difficult species that require live food? Try them in
an outside pond or stock tank. The babies will fend for themselves and
grow to a size that is easier to handle and provide food for.
Better yet, you might be able to establish a self- sustaining population
that requires minimal maintenance and will provide you with a continous
supply of fish to exhibit in your tanks without having to raise them

I do the same with Fundulus from the starhead group- which are even
easier because the fry are very distinct looking, are large and cruise
at the surface which makes them as easy to dip out and raise as
livebearers. Also they take finely ground up flake foods at an early age
which helps put size on them quickly.
Enneacanthus and most other sunfish fry for that matter are tough to
raise because they are dependent on live food and if you have trouble
getting it, then growth is slow and more time spent in that vulnerable

Putting your breeders outside in the summer solves that problem by
letting the fry subsist off the natural zooplankton and small
crustaceans that you don't have to raise. If there is plenty of cover in
the form of submerged plantlife plenty of young will survive. Even in a
300 gallon rubbermaid tank with a couple potted milfoils. I'd recommend
the two native species Myriophyllum heterophyllum and M. pinnatum often
availible in the aquarium trade as "Foxtail". A bundle of cuttings
inserted into a plastic mesh pond basket filled with pea gravel or that
"Profile" type Aquatic Plant Soil will take root and provide cover for
both the breeders and their fry. These plants don't really need soil
since they can feed directly from the water and to a limited extent from
the mulm at the bottom which their roots will grow down into. Since I
recently started experimenting with this method in some of my ponds this
past summer the results are looking encouraging.

Going soiless means no silt to ooze out of the planters into the pond
not to mention the planters are lighter to lift out of the pond when
necessary. Also the growing medium is not as anerobic as conventional
soil based media and I'm sure it contributes significantly to the
surface area availible for colonization by beneficial organisms. Courser
media would also serve as refugia for scuds and other macro-inverts that
adult fish feed on.

I would not recommend this method for water lilies or most marginal
plants- especially if they are going to be fertilized. As a rule : if
you plan on feeding or think it requires soil then you ought to use a
solid sides planters. Some marginals like Iris might work well this way
if they are going to serve as filter plants but I don't know if they
will do well enough to bloom on a regular basis. You could try taking
them out of the pond and dunking in a tub of solution to provide trace
elements but that could be too labor intensive for someone like me with
several ponds filled with plants!

As for the fish some more important notes. I have found that survival
rates of sunfish fry may be better when the parents are left in the same
pond or tub with them. My guess is that the adults may eat some of the
offspring but also feed heavily on dragonfly larvae that will inevitably
get into any uncovered body of water outdoors. This based on personal
observations of tubs with fry isolated verses left in situ with the
parents. In the fry only tanks and tubs small dragonfly larvae became
abundant and young fishes usually disappeared as opposed to the
situation with adult sunfish present. Such observations are most easily
made at night with a flashlight when both sunfish fry and dragonfly
nymphs come out in the open. The nymphs usually cling to the coating of
hair algae on the sides of the container waiting for young fishes and
other prey to come within range.

An additional benefit of keeping parents around may be that predation on
the offspring is less efficent than that by the nymphs but enough to
thin down the population enough so that there is more food availible for
those that remain and allows for more rapid growth and better health
over all.

Jeff from Western PA
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