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Contents:

  1. [M] Hard coral spawning continued...
    by steve/celia.UUCP (Steve Tyree) (16 Apr 92)
  2. [M] Hard coral spawning continued...
    by steve/celia.UUCP (Steve Tyree) (20 Apr 92)
  3. [M] Hard coral spawning continued...
    by krogers/javelin.sim.es.com (K. Rogers) (22 Apr 92)
  4. [M] Hard coral spawning continued...
    by steve/celia.UUCP (Steve Tyree) (22 Apr 92)
  5. [M] Moonlight
    by steve/celia.UUCP (Steve Tyree) (5 Jun 92)
  6. [M] Moonlight
    by anbo/wuee1.wustl.edu (Albrecht Jander) (Mon, 8 Jun 1992)
  7. [M] Moon light for reef
    by steve/celia.UUCP (Steve Tyree) (16 Nov 92)

[M] Hard coral spawning continued...

by steve/celia.UUCP (Steve Tyree)
Date: 16 Apr 92
Newsgroup: rec.aquaria

In article <30346-at-cbmvax.commodore.com> scotts-at-cbmvax.commodore.com (Scott Schaeffer) writes:
>The spawning was induced by a single 175w halide on for a single night.
>The water temperature started to edge up when the lighting was on
>all night so I stopped it until I can build a actinic moonlight setup
>or I get a chiller.

 A simple incandescent lamp or bulb might be all that is needed to simulate
moonlight. I use actinics to simulate twilight, this helps induce the reef
fish to spawn. For these corals to spawn on the same day every year, they
probably use only 2 sensed variables. Due to the fact that corals expand
quite far during daylight and they contract during nite time, they must be
able to sense quite accurately the length (cycle time) of the daylight period.
This combined with moonlight at night, is all that would be needed to spawn
around the same time every year. (also ability to sense trends as well).
 Now, you say that you have left a metal halide on all nite. When did the coral
spawn in relation to the metal halide moonlight. During the moonlight or the
nite after you stoped the moonlight or the second nite of full moonlight ?
ie - Was it a full moon, waning moon, waxing moon or new moon ?
 ps - a computer controlled incandescent "moonlite" would be a real handy
      device to have. :>

 Steve Tyree - Practicing Reef Breeder


[M] Hard coral spawning continued...

by steve/celia.UUCP (Steve Tyree)
Date: 20 Apr 92
Newsgroup: rec.aquaria

In article <30407-at-cbmvax.commodore.com> scotts-at-cbmvax.commodore.com (Scott Schaeffer) writes:
>The elegance spawned the next day after the moonlighting while the
>branched pink hammer spawned 5 days later. I'm wondering whether the
>moon phases can be simulated by varying the duration of a moonlight
>flourescent or whether the light must be dimmed and kept on for full
>12 hours? Any ideas? 
>
  Scott, I have done some Academic research on this and have discovered many
fascinating things. Corals in the Great Barrier reef spawn 3-7 days following
the first 2 Full moons in late spring and early summer. One reason for the
short spawning period might be the local environmental factors in this area.
Major temperature swings and defined summer and spring seasons all force the
coral to spawn during a couple of days. What this means is that we can set
up a long sequence in our reefs and be able to predict when the corals in
our tank will spawn within a few days accuracy. I plan on going into a 6 month
yearly cycle soon. Starting at winter and then spend 3 months leading into 
summer time. If everything goes right I should be able to predict when they
will spawn in 3 months and this time I will have camera and video ready :>
You bring up a good point about the moon light times. The moon is 180 degrees
out of phase with the sun during full moon. ie- its in the sky all night.
During first quarter and third quarter its more in phase and wont shine the
entire night. I think that this means moonlight varies a lot. From no light
to a long full moon. I am putting together a 6 month plan for my tank. The
following parameters will be changed during the 6 month year.

    - Temperature will be low in winter and high in summer. Some believe this
       might stimulate egg and sperm developement.
    - Light diel (cycle) times will be changed. Short daylight times in winter
      and long times in summer. Is 9 hours daylight in winter and 12 hours day-
      light in summer adequate ? Perhaps Jamie might comment on local Great
      Barrier Reef diel times.
    - Moonlight and phase will be twice as fast to correlate with 6 month
      year. I will do this by hand for now. If this works I might try a 4
      month year.
    - Moonlight duration. This requires more research and maybe a computer
      program to calculate accurately.

 ps - All these parameters can be calculated ahead of time and written down
      in cookbook recipe format. Then I will use the previously calculated
      records to determine how to set things each day. The first test will
      all be done by hand. This subject could be a good topic for the Reef
      Breeding Journal. I will try to keep accurate records.

 Steve Tyree - Practicing Reef Breeder


[M] Hard coral spawning continued...

by krogers/javelin.sim.es.com (K. Rogers)
Date: 22 Apr 92
Newsgroup: rec.aquaria

steve-at-celia.UUCP (Steve Tyree) writes:

> A followon question for any math wizards out there. What curve would best
>fit the light intensity from the moon from new to full ? It probably is not
>linear and may even be logarithmic. Anyone have an equation for the curve ?
>
>  Steve Tyree - Practicing Reef Breeder

I'm not a math wizard.  I am a defunct astronomer.  I've goofed around
with writing computer routines to do what you're asking about.  I
expect you're aware that what you're asking for is essentually
impossible to calculate.  The light is affected by how much and which
part of the moon is illuminated (different albedos over its surface),
angle of incidence (higher at the tropics), how many air masses it
passes through and what the transparency is of those masses, humidity,
dust, thin hazes not to mention clouds, evertything alters this, etc,
etc.

For a first aproximation, which I expect is good enough to get corals
to spawn, at least as far as moonlight affects this, you could pick a
latitude and longitude as your home base and calculate moon rises and
moon sets for that location.  If you want to get trickier you could
vary the light brightness by what phase the moon is: something like
half of full brightness of the bulb when the moon is half full and
such likes.

You can buy a small booklet called Astronomy Programs for Your
Calculator by Duffett-Smith or there are a couple books on astronomy
programs for computers (all in BASIC of course, ack, ack)- just look
in any issue of Sky & Telescope magazine to mail order them if you
can't find them locally.
-- 
Keith Rogers
Evans & Sutherland Computer Corp.
krogers-at-javelin.sim.es.com


[M] Hard coral spawning continued...

by steve/celia.UUCP (Steve Tyree)
Date: 22 Apr 92
Newsgroup: rec.aquaria

>steve-at-celia.UUCP (Steve Tyree) writes:
>> A followon question for any math wizards out there. What curve would best
>>fit the light intensity from the moon from new to full ? It probably is not
>>linear and may even be logarithmic. Anyone have an equation for the curve ?

In article <1992Apr22.154853.19841-at-javelin.sim.es.com> krogers-at-javelin.sim.es.com writes:
>
>For a first aproximation, which I expect is good enough to get corals
>to spawn, at least as far as moonlight affects this, you could pick a
>latitude and longitude as your home base and calculate moon rises and
>moon sets for that location.  If you want to get trickier you could
>vary the light brightness by what phase the moon is: something like
>half of full brightness of the bulb when the moon is half full and
>such likes.
>
  Our moon is definitly unique. The only true way would be to actually
 measure the amount of photons received here on earth. I hope we dont
 need to be that accurate. I am trying to reproduce conditions that 
 occured at Australias Great Barrier Reef. Especially during the times
 referenced in the Marine Biology Journal Article "Synchronus spawning
 of 105 species of corals...". I need to know the latitude and longitude
 for the middle area of the Great Barrier Reef and then calculate the
 moon rises and sets and reference this to the sun setting and rising
 times. I am hoping that I end up with a percentage brightness value
 that could easily be utilized by setting an incandescent lamp brightness
 each night. For the first test the light will be on all night. So I
 will calculate the rough brightness of each phase and then bias this
 with the percentage of hours during the night the moon was shining.
 Maybe just knowing the type of curve this would give could provide me
 with a rough guess aproximation. I dont think that a linear changing
 of the brightness with respect to the moon phases will be adequate
 enough. Maybe a sine curve or log based function.

 Steve Tyree - Practicing Reef Breeder


[M] Moonlight

by steve/celia.UUCP (Steve Tyree)
Date: 5 Jun 92
Newsgroup: rec.aquaria

In article <1992Jun5.171200.28505-at-tin.monsanto.com> kncarp-at-nicsn1.monsanto.com (Kevin N. Carpenter) writes:
>Having seen the pretty ads in FAMA for "moonlight over the reef", 
>and also being one who is frequently up after the metal halid
>goes out, I've begun thinking about how to provide low-level
>night lighting for my tank.
>
>I'm curious what the net-wisdom is about using such a device.
>Are any colors better than others?  How much light should I use?
>I was thinking of something like 15-20 watts over my 135 gallon.
>Will the low level light cause any problems with the fish, plants,  
>or future inverts?
>

 I am not familiar with the "moonlight over the reef" product, however I
have been setting moonlight by hand for over a month now. Over my 180 reef
I have an incandescent chandilier with 6-15 watt bulbs. My top front half
of the tank lid is always pulled back and open. The chandilier power is
varied on a linear scale. The scale I am using is the following. (note this
is out of memory).
     .004  .04  .11  .26  .54  .75  1.0  .75  .54  .26  .11  .04  .004
    New                             Full                            New
This results in a sharply peaked full moon intensity. This is being done
during my 3 month experiment leading to inducing coral spawning. Corals
and fish do need a natural rhythmic moon cycle. Experiments have shown that
without moon light corals lose their natural sync and dont spawn or spawn
very irradically. Some fish also key in on moon cycles. Has anyone dived
in a coral reef during full moon and on new moon ? I wonder what the actual
difference appears like in nature. Is it drastic ?
 Note - The chandilier is not directly over the top of the tank. This means
        I am probably using 3 - 15 watt bulbs hung 2 feet over and 1 foot in
        front of the tank. These are soft white bulbs. Looks natural.

 Steve Tyree - Reef Breeder


[M] Moonlight

by anbo/wuee1.wustl.edu (Albrecht Jander)
Date: Mon, 8 Jun 1992
Newsgroup: rec.aquaria

In article <dlcogswe.707807495-at-vela> dlcogswe-at-vela.acs.oakland.edu (Dan Cogswell) writes:
>gt6441c-at-prism.gatech.EDU (Jon Edwards ) writes:
>
>>Ok, this may seem like a dumb question, but IF I were to make some 
>>sort of attempt at moonlight simulation (using blue "screw in" Christmas
>>lights), should there be a time in the middle of the night when there
>>is NO light.  I've never really paid attention to the amount of moonlight
>>we get at different time of the night. 
>[Stuff that actually pertains to this group removed.]
>Dan "Now let's measure our swan candle holder"  Cogswell
>BS in CS looking for a job in 3D graphics somewhere south of Michigan.
>Will work for free.

Well, the moon is relatively complex.  Look on your calendar and see when
the next full moon is.  During a full moon, the moon behaves pretty much
like the sun, only offset by 12 hours.  During a full moon, the earth spins
directly between the sun and the moon (well, close, or else you would have
an eclipse), so pretty much when the sun sets, the moon should rise on the
other side.  At midnight, the moon should be directly overhead.  You should
be getting moonlight all nicht long.
On a quarter moon, the moon will rise/set 6 hours after/before the sun, since
sun, earth and moon create a right triangle.  Also, the moon will be much
dimmer (only partly illuminated, use sines and cosines to determine how much).
During a new moon, you will get no moonlight, since the moon is on the same
side of the earth as the sun.  
Of course ther are all of the in between phases, and times are leangthened
and shortened according to the seasons (tilt of the earth).

So, to simulate a particular phase of the moon would be pretty easy.  Just
run another security timer out of phase with you "sun".
Full moon: 6PM-6AM
Quarter moon: 12 Midnight - 6AM   or  6PM to 12 Midnight
New moon:  Save the timer.

If you do a changing moon, you could hack your timer so that it runs
1.034 times faster than your "sun" timer.  Then you will cycle through
the phases every 29 days.

Well, I hope that is what you were asking about!!

Albrecht


[M] Moon light for reef

by steve/celia.UUCP (Steve Tyree)
Date: 16 Nov 92
Newsgroup: rec.aquaria

In article <Bxs2K1.8IA-at-ra.nrl.navy.mil> tse-at-ra.nrl.navy.mil (Anthony Tse) writes:
->Hello,
->	I am ready to put a moon in my reef.  How is it done?  Do you
-> change the intensity and leave the moon on all night?  Or do you
-> fix the intensity and change the duration it is on?
->    I am planning on doing the former so I don't have to stick my
-> head in my stand to change the timer peg everyday.  The setup
-> is a OSRAM 9W blue bulb since I have a 9W CF fixture in my junk pile.
-> I'll turn it on in the evening when I do my daily routine  and I'll
-> rubber band a piece of cardboard onto the fixture to reduce the light
-> output according to the phase of the moon.  Any comment?

 My moon setup is stimulating some corals to spawn in artificial lunar
rhythms. The moon illuminance is on for the entire night and the intensity
is varied on a linear scale. The intensity value for each day has been 
calculated previously and the scale is listed below.

.0  .01  .02  .04  .07  .11  .16  .22  .28  .36  .44  .54  .64  .74  .86  1
----------------------------------------------------------------------------
New                                  First                              Full

.86  .74  .64  .54  .44  .36  .28  .22  .16  .11  .07  .04  .02  .01
---------------------------------------------------------------------
                             Last

 You could use the above table as a guide for setting the cardboard shield.
It would be best to create a hinged shield with a normalised scale. If you
are doing this as an experiment to stimulate coral spawning, watch the reef
during night twilight for spawns 4-6 days following the full or new moon.
A Gorgonian sp. coral recently spawned in my reef during the full moon phase
for 2 different months. The time of spawn each day was always the same. 
The eggs were released 1 hour after full daylight was achieved for this coral.
Until we know how every captive coral spawns, we have to always take a good 
look at the reef whenever we walk by. 

 Steve Tyree - Reef Breeder


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