SPS successfully captive spawn on demand! - Project Coral

jrpark22000

Premium member
There is a pretty cool article in the new edition of "coral" magazine. They have successfully induced acro valida sps to breed in captivity on demand, sort of. There is a long article on how they provided the proper colony size proper conditions to get the colony to spawn.

The digital edition no longer is free to all but for magazine subscribers you can login below and view it. Starts at page 78&79.

Project Coral - Inducing predictable broadcast spawning of stony corals in captivity
http://subscriber.pagesuite-profess...spx?pbid=b334a533-9e9b-4443-a8b3-12e2db32511a

Link to their website with videos
http://www.horniman.ac.uk/about/coral-research-in-the-aquarium

They did say they will start a kickstarter "project coral" in late March early April.

Any other SPS geeks find this pretty cool?


[video=youtube;JNudCfm4KUk]http://www.youtube.com/watch?feature=player_embedded&v=JNudCfm4KUk[/video]
 
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I was able to download the PDF of the article but couldn't post it. So here is the text from the article.


PROJECT Coral
Inducing predictable broadcast spawning of stony corals in captivity

article and images by Jamie Craggs


Whilst there have been captive coral spawning events in a few public aquariums and
a small number of home aquariums around the world, they have always been unplanned, incidental
events, often catching the onlooker by surprise. So the challenge of spawning corals in a controlled,
predictable way is considerable and presents some major obstacles.
Despite this, I’ve always felt it could be achieved if the approach was right. When we attempt to breed
aquarium animals, the method is the same in principle. First we need to research the individual environmental
and/or nutritional components that trigger a species to reproduce in the wild; then, using
that knowledge, we replicate these conditions in our aquariums. Surely, inducing broadcast corals like
Acropora to spawn in captivity should be no different, even if their environmental cues and triggers are
more elusive to define?
Two years ago my research partner, Gary Fletcher, and I started to plan a multi-year coral research
project. Our aim was a simple but ambitious one: we wanted to predictably induce broadcast corals to
spawn in captivity, then use the techniques we learned to start to understand how climate change might
affect a coral’s ability to reproduce. After a year of planning, in January 2013 we added the first corals to
the research system at the Horniman Museum and Gardens in London. It’s been a journey of discovery,
and this is what we’ve learnt so far.

It turns out there is a surprising amount of information about broadcast coral spawning out there—
in aquarium articles, research papers, and even dive company Twitter feeds! Combining this information
with discussions with aquarists and field observations during SECORE Foundation workshops, these are the
factors we feel must be replicated in order to induce broadcast spawning in captivity: colony size, appropriate
heterotrophic feeding, annual temperature change, photoperiod, and lunar cycle.
The following describes how we have applied each of these factors within our coral research system and induced
our first two broadcast spawnings.

COLONY SIZE—SIZE DOES MATTER!
Colony size seems to be important in initiating egg production, and the size at which a colony matures is species
dependent. The conventional wisdom is that small colonies put all their energy onto growth, something that
makes sense for a sessile animal in a highly competitive environment like the reef. Every square foot is a battleground
where neighbouring corals are at war over space. Small colonies need to establish their space and position.
Once a critical size is reached the coral diverts a proportion of its energy budget into gamete (egg and sperm)
production. A number of research papers provide information on species size during spawning. Fernando Nosratpour
of the Birch Aquarium at the Scripps Institution of Oceanography published a paper in 2008 describing a
number of unplanned spawning events in the late 1990s and early 2000s by an Acropora valida (Dana, 1846) colony
that was 20 inches (50 cm) in diameter at spawning. I’ve had a genotype of this species for the past 10 years,
and this paper gave us the first target size to aim for. A second species we successfully spawned was
Acropora prostrata (Dana, 1846). Again, I had a single genotype of this coral in captivity for six years. I had
worked with this species in the wild, collecting egg/sperm bundles during a SECORE Foundation workshop
in Singapore in 2010. The colonies I was working with in the field were approximate 16 inches (40 cm) in
diameter, giving us our second target size. So, armed with two measurements, I had the idea
that although we had multiple small frags of these two species in various tanks, they were genetic clones and
would therefore undergo isogeneic fusion (fusion of pieces of coral with genetically identical tissue) with no
problem. In late 2012 Jem Simmons, my biologist, and I removed a large number of frags of both species and, using
epoxy putty, attached them to two large pieces of live rock, one for each species, in the belief that placing the
frags close together would cause them to fuse, creating a communication channel across the colony. That way we
could “build” a sexually mature coral rather than waiting a few years for the small frags to grow to that size.
(See images [a] through [f] on page 80.)

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HETEROTROPHIC FEEDING
We had constructed our two sexually mature colonies of Acropora valida (Dana, 1846) and Acropora prostrata
(Dana, 1846). Now we needed an appropriate feeding regime, as we knew this was important for providing
the nitrogen and phosphorus input required for healthy growth and gamete production.
Acropora species can feed on a huge range of prey types. They can absorb free amino acids from the water
column and consume bacteria and protists (picoplankton) and various species of phytoplankton that are
trapped in their mucus. Corals use this mucus layer as a feeding mechanism, employing cilia
located on the surface to move the mucus in and out of the mouth. Acroporacorals also have powerful stinging cells
that they use to capture large motile prey, such as copepods (zooplankton),and these form a large portion of their
heterotrophic feed in the wild. Having identified various prey groups, I had lengthy discussions
with Dr. Dirk Petersen, director of the SECORE Foundation. Dirk has a huge amount of knowledge about heterotrophic
feeding, which he gained during experimental work for his Ph.D. and after. He provided me with various dose rates
that he’d developed while he was at the Rotterdam Zoo, and I based our feeding regime (see images on page 88) on his
advice. The coral research system at the Horniman holds 530 gallons (2,000 L), split into four 130-gallon (500-L) components:
two 65-gallon (250-L) broodstock tanks and two 65-gallon (250-L) sumps that are connected. Each of our broodstock tanks was
isolated for 1–2 hours every morning to concentrate the food and allow uptake.We then added a yeast culture solution at 0.4 ounce
(12.4 ml) per 264 gallons (1,000 L) (picoplankton).We made this three times a week and cultured the yeast
with sugar at 75.2°F (24°C) for 24 hours before use. For the phytoplankton component of the diet we used Reed
Mariculture shellfish diet and aimed for an approximate cell concentration of 48,000 cells per liter. Each tank
also got two frozen cubes of rotifers (1,000–2,000 per liter) and 1.7 ounces (50 ml) of instar II Artemia nauplii
that had been enriched with New Era’s Live Food Enrichment to improve the fatty acid profile. This concentration
yields a prey density of approximately 1,136 naupliiper gallon (300 per L). This feeding regime places a lot of pressure on the
filtration, and we’ve had to increase the percentage of water changed to manage the correct water chemistry.
The feeding regime has also resulted in Derbesia marina and Aiptasia outbreaks, which we have managed both
biologically and chemically.During feeding there is a distinct change in the corals. At first the polyps retract, but over the course
of the isolation they greatly extend, often ejecting their mesenterial filaments (see facing page). The corals also
produce mucus webs to capture and ingest their prey.Each broodstock tank has high internal water flow to
ensure prey suspension and movement.

ANNUAL TEMPERATURE CYCLE
Traditional reefing maintains a nearly constant temperature, but in the wild there is often considerable change
throughout the year. This seasonal fluctuation is one important contributing factor in initiating gamete development.
We based the environmental parameters in our coral laboratory on a Fijian reef because we had a number
of large colonies shipped directly from Fiji, and through replicating the environmental parameters of that location
we intend to spawn these during 2014 (2x Acropora humilis, 4x Acropora valida, and 2x Acropora prostrata).
When planning this project I spent a great deal of time researching these environmental parameters to ensure
accurate replication of the environmental conditions experienced on the reef. We are using a U.S. NOAA sea
surface temperature (SST) data recording buoy to provide our annual temperature regime. This buoy, part of a
global climate change monitoring program coordinated by NOAA, has been uploading SST readings every three
days since 2000. One of the buoy’s roles is to collect data on the likelihood that a bleaching event will occur. We
wanted to create an annual temperature change, but we certainly didn’t want to cause a bleaching event in the
system, so I downloaded the previous 13 years of data and analyzed it. Based on the results, I chose 2011 as the best
model, one that wouldn’t create any bleaching issues. Using this data, Gary programmed the microprocessor to
control the heaters and chiller so that our system would replicate this regime. Overall the system performed well
during 2013, averaging 31.69 degrees (C) from a set point across the year. We plan to improve this by cooling
the space during the hot summer months.

PHOTOPERIOD AND LUNAR CYCLE
In 2011, Boch published a paper that investigated a number of the factors that affect gamete release and spawning
coordination, including sunset and twilight periods, Kelvin light temperatures during these periods, and the lunar
cycle. Through a series of controlled experiments, we determined that the period of total darkness post sunset,
moving through twilight, and prelunar rise in particular is an important factor in synchronizing spawning. Each
day past a full moon the period of absolute darkness extends by approximately 1 hour and, based on Boch’s
results, we have designed an artificial lunar cycle to replicate wild conditions. The research system at the museum
is located behind the scenes and has a long bank of high windows and security lighting through the middle of the
space (see image above). The last thing we wanted was external light levels influencing spawning times, so we
completely blacked out the system (see image on facing page). The front is raised during the day for maintenance
and we simply “put the system to bed” at the end of the day, giving us complete control of this critical parameter.
Our lunar LED units were built by Tropical Marine Centre, UK, specifically for this project and emit the correct
Kelvin temperature of the moon (4,100 K). We spent some time calibrating the LED power output to match
the annual cycle. Maximum lux output at full moon is just 0.1 lux, and our microprocessor controls the LED to
produce 0.1 lux at 100 percent output (full moon) and drops down to 0 percent (new moon) throughout the
month. We’re using the U.S. Naval Observation data for both the photoperiod and the lunar cycle, and this has
enabled us to precisely match conditions on the reef that the corals were collected from using GPS coordinates.
That covers the five parameters (colony size, heterotrophic feeding, temperature cycle, photoperiod, and lunar
cycle) we thought would be needed for successful spawning, and these were all put in place at the beginning
of January 2013. Then it was just a matter of running the system, ensuring water chemistry was closely
monitored, and waiting. Inevitably, there is some doubt when you’re running a new project and trying to break new
ground. You think you have covered each and every detail and meticulously planned. You think it will work because the theory is
sound, but I have to say that when I started to crack the colonies (a term used by researchers, referring to the
process of removing a branch and examining the crosssection for signs of gametes) in early August, I was blown
away on discovering that both the Acropora prostrate and the A. valida we had “built” 8 months previously
were gravid. The A. prostrata had small white oocytes (eggs). Acropora egg development is well documented,
so I could tell we still had 4–8 weeks before it would spawn. The Acropora valida was more developed, and
the oocytes already had orange/pink pigmentation (see image on page 86). These oocytes were in a later stage
of development, and that meant spawning would occur after the next artificial full moon.
Both colonies were cracked a number of times during the buildup to spawning to check development
and photograph the cross-sections. The fragments were preserved in 10 percent formalin and sent off for
histological sectioning. During this process the hard skeleton of the frag is dissolved in acid. The remaining
soft, preserved tissue is then embedded in wax, and 6–8-micron sections are sliced from the wax block,
mounted to microscope slides, and stained to highlight the tissue structures (the pink areas are the oocytes, the
dark purple is sperm). It’s a powerful tool because it has enabled us to document the stages of egg and sperm
development in the buildup to spawning. Microscopic slides also enable us to revisit the stages at any time, and
one of our future goals is to develop a comprehensive library of slides at various stages of development from
multiple species, under varying conditions. The image at the bottom of page 83 follows the oocyte development,
from white to pink, in the A. prostrata over 8 weeks, but I think image (d) best highlights the amazing potential
that captive spawning in a controlled system has for coral research. I preserved this fragment just 10 minutes
before it spawned, and you can actually see the egg sperm bundle inside the polyp mouth prior to release (see
image on page 81, bottom). Preserving fragments this close to spawning in the wild, in a stage called “setting”
(more on this in a bit), would be challenging, so to be able to do this in southeast London is very exciting!
Imaging at higher magnifications, 200x and above, has also enabled us to see sperm orientation along the
mesenterial filaments, within the preserved tissue, on the microscope slides.

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SPAWNING
The first to spawn was the Acropora valida. We had anticipated the spawning date based on the artificial lunar
cycle, but as a precaution the coral was placed inside a spawning collection net (image on page 81, top). Broadcast
corals often have a pre-spawn, releasing a few egg/sperm bundles the night before the main event, so it
was a fairly safe assumption that if a few eggs were floating on the surface when we checked on arriving at work,
the main event would happen that evening. On September 6, 2013, 16 nights after our artificial full moon, a few
hundred eggs were floating in the net, so we knew we were on for the first predicted and planned spawning in captivity.
At the end of the day the system blackout sheet was lowered, cameras prepared, and equipment assembled.
Once the lights had been turned off the colony was periodically checked using red light, and at 9:30 P.M. (21.30) the colony started
to “set.” During setting the egg/sperm bundles move to the polyp mouth and can be seen as a pale orange/
pink area in the oral disc. Approximately 60 percent of the colony had set, and at 11:38 P.M. (23.38) our first
predicted captive broadcast spawning started. There were just a few bundles at first, then more and more polyps
started to release. Bundle release slowed to a stop at midnight, and I estimated 200,000 eggs were released in the
22-minute spawning (see image on page 87). It felt like an incredible milestone had been achieved, and the HD
video footage I managed to capture was simply stunning! Captive spawning is amazing to watch, but it also has
the potential to crash the filtration. The eggs are rich in lipids and a single spawning produces a
lot of organics. A single decaying egg produces an oily slick on the surface if left in the water. Once the spawning had finished
the floating bundles were removed with a beaker and egg counts estimated. Enzyme activity breaks the bundles apart
within 20–30 minutes, separating eggs from sperm, and each minute following release the bundle loosens. The action of
skimming the surface with the beaker was enough to break the bundles, and within seconds the eggs gathered at the
surface and the sperm formed a cloudy solution in the beaker (see images on facing page). We followed the same process the
following month with the A. prostrate colony. This time spawning occurred 17 nights after our artificial full moon, on
October 6. Approximately 40 percent of the colony started to set again at 9:30 P.M. The colony was cracked at 11:00
P.M. and the sample was preserved for histology, as described earlier. Ten minutes later the first bundles were released.
The A. prostrata produced approximately 100,000 eggs in the 31-minute spawning, and we preserved most of the eggs
and sperm for future studies. As each spawning event was from a single genotype, we weren’t able to conduct
any in vitro fertilization, but attending SECORE Foundation workshops has taught us the techniques to achieve this in the future,
and it will be a major focus of 2014.

OUR FUTURE GOALS
We have made what we feel is huge progress during the past year. Our understanding of wild “triggers” and applying
them in our closed system worked, proving our methodology was right. Although the eggs from this
self-fertilized single colony are mostly infertile and not good candidates for propagation, we are importing different
genotypes of the species that we have successfully spawned with a view of having successful fertilzation in
the near future (watch this space!). I feel strongly that this work has enormous potential to open a whole new area for scientific
coral research. It has implications for reef restoration and gaining a deeper understanding of coral reproductive biology and
the effect that climate change might have on fecundity. I think it will ultimately shape the future of the coral
aquarium industry by enabling aquaculture via sexual reproduction.

Jamie Craggs is Aquarium Curator, Horniman Museum and
Gardens, London, UK.


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WE NEED YOUR HELP!
CORAL SPAWNING JOURNAL
We have built an open source website called the Coral Spawning Journal, www.coralspawningjournal.com. We created this so that
researchers and aquarists alike can log spawning events, both in the field and in their aquariums. Through this website we want
to build an open source, comprehensive library of coral spawning events around the world. Have you observed spawning? If so, why
not add your sighting to the website and be part of the future of our industry?

KICKSTARTER
Using our techniques, we want to develop coral sexual reproduction in captivity for the benefit of coral aquaculture and climate
change research, and to do this we need funding and your help. We are planning to build an additional research system,
controlled by our newly designed microprocessor, LEACS (Laboratory Environmental Aquarium Control System). Then we
want to deploy an ocean monitoring buoy on a coral reef in Guam. The buoy will communicate with LEACS via live satellite feed,
transferring data so our research system can replicate in real time the exact conditions on this reef. Through this we will
research the impacts of climate change on coral reproduction. In late March and early April we will be running a Kickstarter crowd source funding campaign.


Would you be interested in sponsoring our work? Then please visit our Kickstarter page (www.kickstarter.com, search for
Project Coral) and pledge what you can. All donations, no matter how small, will be gratefully received. With your help we can do
some amazing coral science!

A video of our first two coral spawnings can be found on the Horniman’s website, www.horniman.ac.uk/coral. It’s well worth a
look to fully appreciate the splendor of these events!
—Jamie Craggs
 
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My personal take away from the article for our SPS tanks is the knowledge about how to improve husbandry. If we use the ability of a coral to be healthy and happy enough to spawn as an indicator of overall health, this article really helps. It goes to show how both target SPS feeding and temp/lighting cycles are as important as water quality and lighting intensity.
 
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This is amazing

thanks for the info Josh, i didnt even know it happens this way .. what a spectacular view it is.
 
NP Tin. Glad I'm not the only geek who finds it fascinating.


Ok, just finished loading the article pictures into the above posts.
 
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I was watching the BBC documentary on the Great Barrier Reef and the spawning was my biggest takeaway. I was wondering if anyone was trying to mimic the lunar phase that gets them to spawn this is a great kickstarter and I would love to see this in person!
 
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