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Re: Hydra
LeeH920226 at aol_com wrote:
>
> In a message dated 3/24/99 8:09:39 AM, BigJohnW at webtv_net writes:
>
> << But where else do they
> come from when I introduce nothing to the tanks except food? >>
>
> I had always assumed they came with daphnia or plants. I never thought there
> was a chance they came from brine shrimp eggs. Does anyone know if hydra can
> survive in salt water? They do keep a container with fry absolutely free of
> pollution from dead brine shrimp, but at the risk of catching small fry. I
> have never seen evidence that they catch fish of any size, just hearsay. They
> do tend to slow down the growth of fry because they eat all the brine shrimp.
> I tend to tolerate them in moderation but eliminate them physically when they
> get too numerous in shoe boxes where I am rearing fry. By decanting the fish,
> snails and plants to another container and then scrubbing the surfaces they
> are reduced to just those attached to the plants or snails. Mine are always
> green, is that the usual color?
>
> Lee Harper
Hi Lee,
I've gotten a pale brown form in great quantities. I once found close to
50 Melanotaenia boesmani fry suspended from hydra - thoroughly caught
and killed. I've also seen young Aphyosemion suspended, but never in any
numbers. I think healthy fry get away, and hydra cull for us. I once
oberved a hydra stinging a 3 day old zygaima, which simply pulled away
from the tentacles and went its way.
I've wondered if they come through the water system encysted. If it
weren't for the acids, maybe our guts would look like our fry tanks. :-)
-Gary
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