>On Mon, 11 May 1998, Mach T. Fukada wrote:
>
>> to try to pump them up with rotifers and green water.
>
>Try microfood for shrimp (although you are probably already too late with
>this batch). Wager can tell you more about it.
>
>> Ours get washed out to sea and spend most of larval
>> development in the marine or estuarine environment. Do you think that
the
>> empires are about the same and may need brackish water for devlopment.
>
>Empires don't need salt to develop, they can do fine in freshwater,
although
>they are not uncommon in upper estuaries. I doubt they'd tolerate full
>salt water, but it would be interesting to know if anyone has tried them
>under marine conditions. Same for Pseudomugil signifer, the two often
>occur together along the east coast.
>
Unmack is right - Empires don't need salt to reproduce. But I think there
may be something in what you suggest. Several fish biologists have reported
to me a very interesting occurrence. The first was Alf Hogan in Queensland
Department of Primary Industries. He sent me some gudgeon fry that he
collected in the Tully River (Nth QLD). I raised them and they turned out to
be Empires. He said that he found a school of migrating fry when he was
surveying around the Tully estuary. The fish were coming from the mangroves
and swimming along each bank. Alf followed the school upstream. It formed a
continuous column from the estuary to the headwater rapids - a long way. The
fry were settling out onto rocks in the rapids and there were literally
billions of them.
This has also been seen in the Burnett River at least as far up as the first
weir and a few other rivers.
Rob Wager
Raintree Aquatics Pty Ltd
Aquatic Environment and Aquaculture Specialists
1002 Caboolture River Road
Rocksberg QLD 4510
AUSTRALIA
Phone: 07 5496 7939 Facsimile: 07 5497 0022
Email: raintree at mail.cth.com.au