Anke Klueter sets up a tent to try to capture some of the
egg-sperm bundles released by coral into the surrounding sea.
Photo: PHILLIP GILLETTE, UNIVERSITY OF MIAMI
“OMG, I think they just spawned on me!”
That was the title of a September blog entry by UB’s
Buffalo Undersea Reef Research laboratory (BURR), which sent five
UB investigators to the Florida Keys this month to study an
underwater mating ritual: coral spawning.
Mary Alice Coffroth, professor of geology, led the research
trip. She explains that corals—which are
animals—reproduce by releasing bundles of egg and sperm into
the surrounding sea. The goal of the visit to Florida was to
collect these bundles and raise young coral for use in scientific
Among other topics, Coffroth’s research team examines how
an algal symbiont in the genus Symbiodinium facilitates the
establishment of coral reefs.
“It is a symbiosis between corals and a single-celled
dinoflagellate alga, Symbiodinium, that allows the corals to grow
into these massive structures,” Coffroth says. “Most
corals acquire their symbionts anew each generation, and my lab is
investigating the early ontogeny of this symbiosis.”
The BURR lab’s coral spawning
blog , created by BURR member Rachel Mellas, provides an
intimate look at the corals’ mating process and at the
research team’s daily life in Florida. The scientists carried
out their work at the Alligator and Looe Key reefs off the Florida
coast, where schools of tropical fish dart through turquoise
Gathering and rearing the coral was a massive undertaking, and
the BURR scientists were joined by more than 20 volunteers from
South Florida that assisted in all aspects of work.
The Sept. 13 blog entry captures the team’s excitement at
finally witnessing coral spawning:
“We were relieved to see that it was actually happening!
In preparation for a synchronized release of their egg-sperm
bundles, coral polyps will move these pinkish balls into their
mouth causing the polyps to swell and the egg-sperm bundles to be
visible in the polyp mouth. Setting gives us about a 15-20 minute
window to get our dive and snorkel teams into the water and to get
ready to collect before the spawning begins.
“An amazing phenomenon is that the rest of the organisms
on the reef seem to know what is coming and come out of their usual
hiding place. When the spawning begins, these organisms take
advantage of the extra food in the water as well and we can
actually feel them on our hands, face and any exposed skin. We saw
brittle stars, mysid shrimps and many fish active on the reef that
night. We waited patiently with the rest of the reef community
until, almost all at once, around 11:15 p.m., all of the Montastrea
faveolata colonies released these bundles into the water where they
slowly float to the surface (or into our collecting
Unfortunately—as often is the case with
fieldwork—the research mission did not go as hoped. Though
the scientists obtained some coral and sperm samples for research,
none of the young coral the team raised survived. Shelby McIlroy,
Coffroth’s graduate student, will travel to Curacao at the
start of October to try and catch the coral spawn there so the BURR
lab can continue its experiments.
The coral spawning fieldwork supports a number of BURR projects,
such as research scientist Anke Kleuter’s investigation into
why the coral species Montastrea faveolata is compatible with some
algal symbionts, but not others.
McIlroy, a PhD candidate, is studying the benefits to the coral
of having one symbiont type versus another. She is looking at
growth, survivorship and temperature sensitivity of young M.
faveolata corals with different types Symbiodinium. This line of
inquiry will help scientists understand and predict how reefs will
fare in warming oceans. And master’s student DJ Valint is
studying whether certain species of adult corals pass their algal
symbionts along to their offspring in the egg-and-sperm
“Why study reefs? Reefs are important apart from their
intrinsic beauty and high biodiversity,” Coffroth says.
“There are important economic reasons to care about coral
reefs. Coral reefs can be a rich source of natural products with
important pharmaceutical applications. They are also an important
barrier against shoreline erosion. Coral reefs support commercial
and recreational fisheries, and they are one of the primary
attractions for millions of snorkelers and recreational scuba