Re: [RML]P. cyanodorsalis

Mach T. Fukada (fukada at hawaii.edu)
Mon, 28 Dec 1998 10:59:09

Dave,
thanks for the info. Maybe the rains/floods trigger hatching and the fry
get swept out to sea? I have been seeing that all I need to do to trigger
a mass hatching is stirring up the gravel. All they eggs that are ready
just hatch. I figure they eggs develop all the way until they are eyed up
and remain dormant. I need to do some testing on my side. I wonder if I
can go without changing water for about 3 months and then do a massive
water change. maybe before this do a survey of all the eggs on the bottom
of the tank.

MTF

At 10:28 AM 12/28/98 -1000, you wrote:
>Mach T. Fukada asked about P. cyanodorsalis fry in the wet season.
>
>Today, I went to Leanyer to have a look for fry of P. cyanodorsalis and
>found plenty in the creeks that drain Leanyer swamp (Leanyer swamp is
>marine). The creeks that were running were fresh water pH 7.2, TDS 30
>parts per million, temp 26 deg C. The creeks that were not running were
>brackish pH 7.8, TDS 18 parts per thousand, temp 34 deg C. there were some
>brackish places that were warmer and did not have any fry. That is not
>hard to explain because we have had spring tides since the heavy rains of
>cyclone thelma, perhaps the 7 meter spring tides pushed the fresh water
>back in places where there was no fresh water running creek to flush it
>away. The creeks of leanyer drain into Buffalo Creek then the sea which
>is about five kilometers away. The entire mud flats were very wet and
>difficult to walk on. Ususally we are able to drive across the flats in a
>4WD vehicle with caution. I also went to the mouth of Buffalo Creek about
>200 meters from the Sea. There were plenty of adults and fry there, and
>the water was normal sea water, pH 8.2, Salinity 34 ppt, temp 27 deg C.
>All of these places mentioned are within 10 - 15 kilometers of the business
>centre of Darwin NT.
>
>Dave Wilson
>
>
>
Mach T. Fukada, Editor
fukada at hawaii.edu
Honolulu Aquarium Society
http://www.geocities.com/Heartland/Meadows/2948/HASF.html