Re: [RML] Re: Gobies; P. cyanodorsalis

Bruce Hansen (bhansen at ozemail.com.au)
Fri, 4 Dec 1998 11:02:35 +1000

Mach I always found the addition of FW to the hatching container seemed to
work like magic if they were slow to hatch. I suspect that in nature the
eggs are laid on the margins of the surface waters on grass, flotsam,
mangrove rootlets etc and the tidal influences vary the salinity as well as
the rains.

I agree that they will tolerate wildly varying salinities almost instantly
and it is only over a few months that you notice the falloff in vigour,
fertility etc if kept too "dilute". If you bring them up to full marine for
a few weeks then they seem to recharge their batteries and will be right for
a few more months again.

This is a fish that spends 80% of their time in the top 3 inches of the
aquarium so don't keep them below eye-level or you'll never see them

Regards,
Bruce.

Bruce Hansen, A.N.G.F.A., Advancing Australian Aquatics.

Bruce Hansen, ANGFA, caring for our aquatic ecosystems.

Please visit us at http://www.ozemail.com.au/~fisher/angfa.htm

-----Original Message-----
From: Mach T. Fukada <fukada at hawaii.edu>
To: rainbowfish at pcug.org.au <rainbowfish at pcug.org.au>
Date: Friday, 4 December 1998 9:46
Subject: Re: [RML] Re: Gobies; P. cyanodorsalis

>At 12:39 PM 12/3/98 -1000, you wrote:
>Been fooling around with these guys and I have some of them in 20 gallon
>tub, with 1 tsp salt per gallon (same as I use to raise Nothobranchius).
>They seem to be OK, however there is a generous portion of crushed coral in
>the tank to boost the hardness, buffering and pH. I do think that they
>fairly susceptable to radical changes in pH, rather than changes in
>salinity as I can usually aclimatize these fish down to 1 tsp salt per
>gallon over the course of one afternoon. I have noticed that the eggs seem
>to be more willing to hatch in water with less salinity.
>
>Got a question for Dave Wilson who wrote:
>> The P.cyanodorsalis that live in Darwin harbour are in full marine >water
>for 8 or 9 months of the year and brackish to fresh during the >wet season
>depending on the amount of rain that is falling.
>
>Do you notice there are more fry in the streams during the wet season? I
>have noticed that the eggs seem to all most go dormant until there is a
>change in water movement or drop in salinity.
>