50% seawater is OK but if they are slow to hatch just drop the salinity in
with the eggs - perhaps down to 20% and they usually hatch out in a few
hours
BTW Cyanodorsalis often lay their eggs on the glass - you might be
surprised how many eggs you get just by cleaning the glass with a sponge
gently
They live in very tidal and monsoonal areas - so can take a wide range of
salinities with almost no adjustment. I just found that they won't last as
long in FW as brackish - perhaps their bodies just leak out too much of
their body salts and can't replenish them
Regards,
Bruce.
Bruce Hansen, ANGFA, caring for our aquatic ecosystems.
Please visit us at http://www.ozemail.com.au/~fisher/angfa.htm
----------
> From: Mach T. Fukada <fukada at hawaii.edu>
> To: rainbowfish at pcug.org.au
> Subject: Re: [RML] News Flash - DNA
> Date: Friday, 24 April 1998 23:29
>
> Hi Bruce,
> yah something like that. BTW I am looking at some P. cyanodorsalis fry
I
> got fatching out right now at my desk. Kinds seem to need to force the
> eggs to hatch. It is conveniant in that I can get a bunch all the same
age
> and size. Makes rearing them easier. Was wondering if something might
be
> wrong with the water. I have been told that 50% seawater is a bit high.
> Could my water be to salty, or perhaps my Ca++ to high causing the egg
> shells to harden and the fry can't break out without help. Maybe it is a
> new species ;-).
>
> MTF
>
> At 01:12 PM 4/24/98 -1000, you wrote:
> >I like Mach's observation that perhaps we can use the DNA separation of
> >morphologically similar "species" to help us define a group to examine
more
> >closely for physical differences.
> >
> >I think that's what he was saying ;-)
> >
> >Regards,
> >Bruce.
> >
> >Bruce Hansen, ANGFA, caring for our aquatic ecosystems.
> >
> >Please visit us at http://www.ozemail.com.au/~fisher/angfa.htm
> >
> >
> >
> >----------
> >> From: Mach T. Fukada <fukada at hawaii.edu>
> >> To: rainbowfish at pcug.org.au
> >> Subject: Re: [RML] News Flash
> >> Date: Friday, 24 April 1998 20:50
> >>
> >> At 03:36 PM 4/23/98 -1000, you wrote:
> >>
> >> In fooling around with PCR analysis I recall asking the question as to
> >"can
> >> it tell me that we are dealing with different species?" I was looking
at
> >a
> >> beetle that some how was able to feed on over 355 different species of
> >> plants (many are unrelated plant species). I suspected that there was
> >> really a species complex involved and wanted to look into this problem
> >via
> >> PCR. I was told that there was no criteria set for differentiating
> >between
> >> species (after all a species is an artificial taxon developed to help
us
> >> "pidgeon hole" groups of related organisms". I suppose it made sense
at
> >> least in dealing with insects and differentiating between sympatric
> >> populations of the same organisms. There could be radical differences
> >> between the two populations genetic make up, yet have no morphological
> >> differences. i.e. sweet potato whitefly and silverleaf whitefly.
Also
> >in
> >> cases in which certain insects develop resistance to pesticides, etc
can
> >be
> >> mediated by mutations of the endosymbionts, which would result in huge
> >> differences in genetic make up (allozymes, and isozymes also I think),
> >but
> >> no change in morphology (endosymbiont evolution theory). Now it is
> >> possible that there are morphological characteristics that were not
> >> considered and as we study further we will find the characteristics
that
> >> will differentiate these cases where there are very simmilar appearing
> >> organisms. However, on the other hand I prefer the ecological
approach
> >and
> >> biological species concept. Of course it might not work in the cases
of
> >> sympatric species, or are they really species if naturally occuring
> >hybrids
> >> are formed....
> >
> >
> Mach T. Fukada, Web Master
> fukada at hawaii.edu
> Honolulu Aquarium Society
> http://www.geocities.com/Heartland/Meadows/2948/HASF.html