|
Note from the author:
This report will be continued next month.
I felt this would be a relatively simple undertaking, but
it has been far from anything resembling simple. Because of
the incredible amount of time required in sorting through
this information and getting in contact with the various aquarists
for confirmation of aspects of the events, I am unable to
present all of the spawning reports this month. I had also
downloaded some of the photos using the America Online web
browser prior to setting preferences that allowed for images
to be used without the AOL proprietary "art" file type. I
have been unable to convert or re-obtain those photos to date.
Finally, more spawning reports are being presented to me in
my "investigation" of some of the events mentioned here. Because
of research and travel requirements, it will be several months
before all of the final details of the incomplete listings
are gained. I will present those details as well as additional
information on aquarium related spawning events in an upcoming
article.
Introduction
Last month, I reviewed the processes of
sexual spawning in reef corals, and discussed some of the
environmental parameters that are thought to be involved with
such events. I also mentioned how such events in aquariums
are relatively rare or unpredictable. This month, I will offer
some of the many reports of sexual spawning in aquariums that
I have been collecting and amassing for nearly five years.
Most of the earlier reports were verbal only, and so I consider
these perhaps less important as they were unable to be verified.
However, the past few years have seen the emergence of perhaps
the most important tool ever conceived for the advancement
of the hobby: the digital camera.
Today, with one in four households in the
US owning a digital camera, the unprecedented spread of photographic
documentation of events in aquariums can now be passed nearly
instantly around the world. While this is often merely to
show pictures of animals present for identification or, equally
often just out of pride for their tank, it has also allowed
many thousands of people to quickly send photos of events
and organisms they may not completely understand to those
with more expertise or experience. Often, what began as a
mere curiosity has proven to be truly remarkable. As an example,
consider the phenomena of "gemmae" (Weil in press)
and "tissue flows," novel forms of asexual reproduction
that had been previously considered as "polyp ball formation"
in the aquarium literature. This behavior occurs across many
taxa of stony corals, and until recently had never been reported
in reef corals (Borneman in press). The same efficiency is
also now used to confirm photos of sexual release in captive
reef corals. What has resulted is, in many cases, the first
reports of their kind; not only in terms of reproduction in
captivity, but also providing evidence of modes of sexual
reproduction unreported in the wild and even contrary, in
some cases, to the currently recognized mode of reproduction
for a species.
In the scheme of things, it was not long
ago that Steve Tyree wrote an article in the the now defunct
Aquarium Frontiers magazine that was the first documented
spawning of corals in captivity (Tyree 1994), an event followed
by anecdotal reports of spawning in various tanks that may
have predated or occurred at nearly the same time by Nilsen
and Fossa (1998). The authors offered the following comments
at that time:
"As we have pointed out above, the
reproduction of stony corals is a very complicated and variable
process and is still a rare event in a coral reef aquarium.
It is anything but easy to manage to get stony corals to
go through their complete life cycle in an aquarium. However,
taking into consideration the rapid development of coral
reef aquaristics during the last ten years, we dare say
that more and more reports about the sexual reproduction
of stony corals in aquaria will soon be published.
We would like to suggest here that aquarists
give this task their undivided attention and report on their
observations, either in articles, or notes in aquarium magazines,
or by writing to us directly…"
To Alf Nilsen and Svein Fossa, I say, "You
were right - as usual." And, I have taken your suggestion,
and hope others reading this article and your books will do
the same. In return, I would also like to offer that anyone
with a suspected or future event of spawning in aquariums
record such events as closely as possible and send me the
descriptions and documentation to act as a temporary repository
of such events until I can finish plans to create a database
for these events. I am also, of course, open to anyone's ability
to help me create such an interactive site as time is always
a factor in allowing the rapid progression of such things.
Previous Reports of Sexual Reproduction in Aquarium
Corals
I offer the following summary of confirmed
and anecdotal reports of sexual reproduction based primarily
on the published works of Tyree (1994), Nilsen and Fossa (1998),
Delbeek and Sprung (1994, 1997), and from The Breeder's Registry
(anon. 2002). I am not offering spawning events as documented
by the Waikiki aquarium because of the semi-closed nature
of the systems. I also regret any previous documentations
not mentioned or listed from the sources below.
|
Euphyllia divisa
|
Nilsen and Fossa
|
Nilsen and Fossa
|
Sperm
|
Nov 2, 1992
|
|
Fungia fungites
|
Nilsen and Fossa
|
Nilsen and Fossa
|
Sperm
|
April 8, 1993
10:30-11:15 am
|
|
Polyphyllia talpina
|
Nilsen and Fossa
|
Kjell Nagy
|
Sperm
|
Nov 21, 1993
11:00 pm
|
|
Sarcophyton sp.
|
Nilsen and Fossa
|
|
Eggs
|
|
|
Rhodactis indosinensis
|
Fossa and Nislen
|
|
Eggs/egg-sperm bundles
|
|
|
Swiftia exserta
|
Fossa and Nilsen
|
Steve Tyree
|
Eggs
|
unknown
|
|
Pocillopora damicornis
|
Many
|
Many
|
Planulae
|
|
|
Mycedium elephantotus
|
Eric Borneman
|
Eric Borneman
|
Sperm
|
July 19, 1999
1:00-2:30 am
|
|
Euphyllia spp.
|
Delbeek and Sprung
|
“Aquarists”
|
“Sperm and Eggs”
|
Unconfirmed
|
|
Tubastraea aurea
|
Delbeek and Sprung
|
unlisted communications
|
Planula larvae
|
Unconfirmed
|
|
Alcyonium
sp.
(note: probably not Alcyonium)
|
Delbeek and Sprung
|
R. Mascarin
|
Eggs
|
Not mentioned
|
|
Trachyphyllia
geoffroyi
|
Tyree
|
Steve Tyree
|
Eggs
|
See Tyree 1994
|
|
Rhodactis/Discosoma
sp.
|
Tyree
|
Steve Tyree
|
Planulae
|
See Tyree 1994
|
|
Euphyllia ancora
|
Tyree
|
Steve Tyree
|
Eggs
|
See Tyree 1994
|
|
Elisella sp.
|
Tyree
|
Steve Tyree
|
Eggs
|
See Tyree 1994
|
|
Pocillopora verucosa
|
Tyree
|
Steve Tyree
|
Planulae
|
See Tyree 1994
|
|
Favia fragum
|
Anon
|
|
Planulae
|
Dec.15-19, 1997
|
Recent Reports of Spawning in Aquarium Corals
The following is a tabular and graphical
compilation of sexual reproduction of aquarium corals, with
notes, as have been offered to me by aquarists around the
world. I apologize to anyone whose reports I have lost, forgotten,
or omitted, and urge anyone to send me files for future reports.
In such cases, please provide and document as much information
as you can, especially information such as is provided below.
I must also apologize for any inconsistencies in the reporting
of these events, as it is not always an easy thing to make
and keep in contact with some aquarists to get complete information.
In any event, for many of the listings
below, these are the first reports of spawning for the species
in captivity, and for some, the first report anywhere, at
least to my knowledge.
|
Montipora digitata
|
Adam Sutherland
|
Victoria, BC, Canada
|
Eggs or egg-sperm
bundles
|
January 16, 2002;
12pm; one hour before "sumset"
|
Notes: 14 month old colony;
grown from previously captive-raised fragments.
|
Sinularia
sp.
|
Skip Attix
|
Hattiesburg, Mississippi
|
Eggs or egg-sperm
bundles
|
August 27, 2001;
11pm
|
Notes: This spawn happened
during the warmest month for tank temperature and about
one hour after "sunset."
|
Galaxea fascicularis
|
Eric Chu
|
Dearborn Heights,
Michigan
|
Eggs
|
April 14, 2003; appproximately
11pm
|
Notes: Unusually warm tank
temperature.
 |
 |
|
White egg being
released visible near center of photo
|
|
|
Plerogyra sinuosa
|
Kedd Lyttonsmith
|
Stamford, CT
|
Sperm
|
February 27, February
28, 2003; 5 minutes prior to "sunset"
|
|
Plerogyra sinuosa
|
Kedd Lyttonsmith
|
Stamford, CT
|
Sperm
|
March 24, 2003; 15
minutes prior to "sunset"
|
Notes: colony
in system for five years. Split spawn, one month apart.
|
Acropora
sp.
|
Andy Bourke
|
Melbourne, Australia
|
Eggs
|
March 25, 2003; 10pm
|
Notes: Acropora collected
six months earlier from the wild and spawned in synchrony
with the wild reefs. Another Acropora sp. had spawned
in the tank six weeks earlier.
|
Psuedopterogorgia
bipinnata
|
Lisa Page
|
Derby, United Kingdom
|
Eggs
|
January 23, 2003;
morning for 24 hours
|
Notes: Lisa believed she observed
5mm green eggs floating in the tank at night on March 26,
2002 during a full moon; however, the organism responsible
was not identified. Photo below.
|
Protopalythoa
sp.
|
Michael Gerdes
|
Silver Springs, Maryland
|
Sperm and eggs
|
December 4, 2001;
around 6:15 am, prior to "sunrise"
|
Notes: the color of the eggs
is unusual in this zoanthid. Streams of gametes were also
seen occurring from unidentified organisms remote from this
colony but were not identified. The event occurred seven
days after a full moon.
|
Muriceopsis flavida
|
Jeff Rusynyk
|
Cleveland, Ohio
|
Eggs or egg-sperm
packets
|
|
Notes: This gorgonian "hangs
onto" the eggs, and they were not completely released
for several days.
|
Catalaphyllia
jardinei
|
Kevin Pockell
|
Veradale, Washington
|
Egg-sperm bundles
|
May 17, 2002; night;
15 minutes before "sunset"
|
Notes: This coral had been
in captivity for three and a half years and had a skeleton
approximately 30cm in length. Eggs were highly buoyant,
strong smelling, tan colored and larger than a pea with
some as large as a marble. Bundles broke after floating
at the surface releasing small white eggs.
|
Galaxea fascicularis
|
Wayne
|
Quincy, Massachusetts
|
Eggs
|
September 2, 2002
|
Notes: Coral had been in this
aquarium for three years prior to the spawning event. Eggs
were released for approximately 30 minutes.
|
Favia sp.
|
Kevin Pockell
|
Veradale, Washington
|
Eggs
|
June 21, 2002;Evening
after "sunset"
|
Notes: This colony had been
in the aquarium for 4 1/2 years. The aquarist also had Catalaphyllia
jardinei spawn a month earlier.
|
Briareum sp.(Pachyclavularia
violacea)
|
Shao ng
|
Burnably, British
Colombia, Canada
|
Egg-sperm packets
|
June 10, 2001 at
5-6pm for 1/2 hour, middle of the "day"
|
|
Briareum sp.(Pachyclavularia
violacea)
|
Shao ng
|
Burnably, British
Colombia, Canada
|
Egg-sperm packets
|
December 28, 2001
at 9pm for 1/2 hour, 2-3 hours before "sunset"
|
|
Briareum sp.(Pachyclavularia
violacea)
|
Shao ng
|
Burnably, British
Colombia, Canada
|
Egg-sperm packets
|
January 17, 2002,
3-4 hours after "sunrise"
|
|
Briareum sp.(Pachyclavularia
violacea)
|
Shao ng
|
Burnably, British
Colombia, Canada
|
Egg-sperm packets
|
May 10, 2002 at 6pm
for over 24 hours
|
Notes: The species does
not appear to be a surface brooder as described in the scientific
literature, or at least is not in all cases. This coral
appears to undergo biannual reproduction and is a simultaneous
hermaphrodite. The spawning period is extended, and occurs
day and night. This coral was in the aquarium for eight
months, and had previously been in another aquarium for
an unknown length of time.
|
Spawn 2
|
 |
|
Spawn 3
|
 |
|
|
Briareum sp.(Pachyclavularia
violacea)
|
Marco
|
Montgomery, Texas
|
Egg-sperm bundles
|
December 19-20, 2001,
before sunset for thirty minutes
|
Notes: Gametes remained
on the surface of the coral overnight, slowly being released.
|
Euphyllia ancora
|
George
|
|
Eggs
|
February, 2002
|
Notes: reported to happen
every 4-5 weeks; eggs collect inside tentacles as in other
reports.
|
Cynarina lacrymalis
|
Jules
|
|
1mm white and grey
eggs or egg-sperm packets
|
9pm for approximately
1 hour
|
Notes: coral in aquarium for
six weeks; spawning occurred after period of strong growth
and feeding; had spawned two years earlier; spawn resulted
in decreased pH (6.4) and ORP; aquarist reports spawning
of Pocillopora sp. 4 weeks earlier (egg and sperm?)
during full moon that resulted in death of tank inhabitants.
|
Euphyllia
sp.
|
Darksky
|
Calgary, Ontario,
Canada
|
Sperm
|
February, 2003
|
|
Briareum sp,
(Pachyclavularia violacea)
|
downrigger
|
|
Eggs
|
|
Notes: 4 colonies spawn
periodically during full moon at night. Eggs produced and
remain on surface, and released slowly over the course of
the following day.
|
Euphyllia parancora
|
George
|
|
Small yellow eggs
|
For approximately
one hour in evening prior to "sunset"
|
Notes: Eggs visible in tentacles
2-5 days prior to release; colony hosts a single A.
ocellaris.
|
Briareum sp,
(Pachyclavularia violacea)
|
Marco
|
Montgomery, Texas
|
Pink eggs or egg-sperm
packets
|
Afternoon for approximately
30 minutes
|
Notes: : Eggs produced
in late afternoon and remain attached to surface being released
over approximately 12 hours.
|
Briareum sp,
(Pachyclavularia violacea)
|
Matt
|
|
Pink egg-sperm packets
|
Overnight
|
|
Seriatopora caliendrum
|
Matthew
|
Austin, Texas
|
Clear to white eggs
|
1:15 pm and late
afternoon before "sunset"
|
Notes: Colony size is
6" x 6" x 4"; colony spawned two consecutive
days.
|
Sarcophyton
sp.
|
John White (Aquaman)
|
Orlando, Florida
|
Eggs
|
April 4, 2003 for
30 minutes at 10pm one hour after "sunset"
|
Notes: Each polyp released
approximately 12 eggs.
|
Tubastraea
sp.
|
Todd Crailz
|
|
Eggs, egg-sperm bundles,
or planulae
|
August 22, 1999 for
approximately one hour during the day
|
Notes: Unusually high
temperatures in the aquarium during event and polyps looked
degenerated after the event. Likely stress-induced.
|
Briareum
sp.(Pachyclavularia violacea)
|
Mike Roese
|
Arroyo Grande, CA
|
Egg-sperm packets
|
|
Notes: Reports of this
colony spawning four or five times.
|
Briareum sp.(Pachyclavularia
violacea)
|
Tom
|
Maryland
|
Egg-sperm packets
|
1999, 2000, March
23, 2001
|
Notes: Colony had been
in the aquarium for nearly three years prior to first spawning.
Colony spawned annually for subsequent three years. Colony
was sent to Eric Borneman in 2002 and has not spawned again
since.
|
Millepora
sp.
|
Allan Skulicz
|
Pittsburgh, Pennsylvania
|
Eggs
|
Date not recorded;
at "night"between 2 am and 6 pm.
|
|
Euphyllia ancora
|
Barry
|
Santa Barbara, California
|
Eggs or egg-sperm
packets; salmon colored
|
April 9-10, 2003;
April 21-23, 2003, 4:30pm in “afternoon”
|
Notes: Colony produces
visible eggs in tentacles prior to release a few days later;
colony produced and released eggs during two intervals two
weeks apart; “eggs” should be examined to ascertain
if these are brooded planula larvae.
|
Multiple species
|
Len
|
|
Multiple types
|
|
|
Discosoma/Actinodiscus
sp.
|
|
|
Sperm-egg packets;
dark olive large clusters (13mm)
|
“irregular but
frequent"
|
|
Amplexidiscus/Rhodactis
sp.
|
|
|
Sperm
|
“irregular but
frequent"
|
|
Acropora spp.
(3)
|
|
|
Eggs and sperm
|
August-September
|
|
Pocillopora
sp.
|
|
|
Eggs
|
“irregular but
frequent"
|
|
Fungia spp.
(3 separate polyps)
|
|
|
Sperm
|
August-September
|
|
Sinularia
sp. (2 different colonies)
|
|
|
Small ivory-cream
colored eggs
|
August-September
|
|
Lobophyllia
sp.
|
|
|
Eggs
|
September, 2002;
once only
|
|
Polyphyllia
sp.
|
|
|
Eggs
|
December, 2002; once
only
|
|
Zoanthids
|
|
|
Eggs
|
“irregular and
infrequent"
|
|
Heteractis crispa
|
|
|
Sperm
|
“irregular and
infrequent"
|
|
Macrodactlya doreenisis
|
|
|
Sperm
|
“irregular,
several times during the year”
|
|
Euphyllia glabrescens
|
|
|
Sperm
|
Around Feb 14, 2002
|
Notes: Aquarist notes
corals tend to spawn in either early morning or slightly
before “sunset.” Anemones spawn during the day
in late afternoon. Some spawns initiated from accidental
temperature drop; no definitive settlement of any species
to date but filters in aquarium run continuously; colonies
from less than one year to 15 years old.
|
Multiple species
|
James Feltham
|
|
Multiple types
|
|
|
Briareum sp.
(Pachyclavularia violacea)
|
|
|
Egg-sperm packets;
0.5 mm reddish; 300-700; not directly released (attached?)
|
|
|
Cavernularia sp.
- obesa?
|
|
|
planulae larvae;
mixed sizes, approximately 0.5mm average; 150-200; creamy
white, some oval in shape
|
11 am; 90 minutes
after “sunrise” for 30-45 minutes
|
|
Favia sp.
|
|
|
Egg-sperm bundles;
small grey eggs released after breaking at surface
|
1999; at night
|
|
Xenia sp.
|
|
|
|
|
|
Non-coral species:
Astraea sp.;
Tridacna crocea (sperm);
Polychaete “tube worms”;
“cleaner” shrimp (every 2-3
weeks)
|
|
|
|
|
|
Multiple species
|
Rich
|
|
Multiple types
|
|
|
Macrodactyla doreensis
|
|
|
Eggs?; light green
|
June 6, 2000
|
|
Discosoma sp.(green
frilly)
|
|
|
Egg-sperm packets
|
|
|
Fungia sp.
|
|
|
Sperm
|
“occasional"
|
|
Actinodiscus/Discosoma
sp.
|
|
|
Eggs?; hundreds;
small, blue
|
|
|
Other non-coral
species:
Trochus sp.; Amphiprion percula
|
|
|
|
|
Other
Cnidarians:
|
Entacmaea quadricolor
|
Eric Borneman; Ralph;
numerous others
|
N/A
|
Sperm
|
|
|
Stichodactyla
haddoni
|
Ronald Shimek, anon.
(multiple)
|
|
Eggs and sperm
|
|
Summary:
Spawning events are not easily documented
for a number of reasons. First, they occur relatively quickly,
and without much advance warning. They may be easily missed
by even the most observant aquarists. They also occur often
at night, when tank lights are either dim or not on at all,
and as such may be even more difficult to witness. If, by
some fortunate happenstance, a spawning event is witnessed,
the experience may be so surprising and fascinating and exciting,
the aquarist may forget to note much more than the time it
occurred, perhaps firing a few hasty photographs to show fellow
reef aquarium enthusiasts. Much of the documentation may be
in retrospect, including the various events that may have
led to the event. With each day and hour that passes, putting
together the pieces of what is still a truly extraordinary
event in captive systems becomes more difficult to do with
accuracy. The events of this article are testimony to these
facts, and I hope that the descriptions – both in what
they contain and what they lack – can serve as inspiration
to the many aquarists who may one day have their own spawning
events occur. Certainly, many such events have occurred and
been either never actually witnessed or reported, or perhaps
being thought of as rather common or unimpressive. I hope
these reports will also prompt more careful recording and
documentation, as well as allowing for a forum to exist for
those who have spawning events occur; a place for those fortunate
few to submit their experiences and observations. Truly, these
events must be logged for the growth and success of this hobby.
Next month, I will conclude this series
of articles and summarize the information presented in this
and the following article’s spawning reports in terms
of trends and potential methods to increase our knowledge
and experience with sexual reproduction in captive aquarium
corals.
|
