Reproduction in Aquarium Corals: Part II

Reproduction in Aquarium Corals: Part II.
Reports of Sexual Spawning in Captivity

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.

Spawning Event #1

Plerogyra sinuosa colony prior to spawning

Spawning Event #2

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.

Acropora sp.

Eggs

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.

If you have any questions about this article, please visit my author forum on Reef Central.

Reproduction in Aquarium Corals: Part II - Reefkeeping.com