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Coral
Reef Science: Development Highlights
Eric
Borneman
Fox HE. 2005. Rapid coral growth on
reef rehabilitation treatments in Komodo National Park, Indonesia.
Coral Reefs 44(2): 263.
The authors note that the greatest recovery
occurred when dynamited areas were simply piled together as
a three dimensional structure of rocks. This may have implications
in coral fragmentation and grow-out facilities.
Rodriquez-Lanetty M, Scaramuzzi C, Quinnell
RG, and AWD Larkum. 2005. Transport of symbiotic zooxanthellae
in mesogleal canalas of Zoanthus robustus? Coral Reefs
24: 195-196.
It has long been wondered how zooxanthellae
that lie within endoermal cells that do not directly connect
to the coelenteron are expelled during bleaching events. This
study shows how the extensive and interconnected mesogleal
canals are able to transport zooxanthellae within, and
correspondingly out, of a coral during bleaching events. The
implications to other corals are discussed, as well as the
possibility of transport of acquired zooxanthellae to sites
into a polyp of colony.
C. P. Marquis , A. H. Baird, R. de Nys,
C. Holmström and N. Koziumi. 2005. An evaluation of the
antimicrobial properties of the eggs of 11 species of scleractinian
corals. Coral Reefs 24: 248-253.
Abstract:
Potential sources of mortality of marine invertebrate larvae
are numerous and include predation and diseases caused by
marine microorganisms. Extracts from the eggs of 11 coral
species were evaluated for their ability to deter surface
attachment and inhibit the growth of two marine tolerant laboratory
bacteria and 92 bacterial strains isolated from seawater and
the surface of coral colonies on the Great Barrier Reef (GBR).
Extracts of the eggs of Montipora digitata inhibited
the growth of the two laboratory bacteria, Vibrio harveyii
and Bacillus subtilis, and one bacterial isolate from
the mucus of the coral Favia pallida in disc diffusion
and liquid culture assays. No other microbial strains (n=91)
from the surface of corals and the reef environment were inhibited
by M. digitata extracts. No antibacterial activity
was found in the egg extracts of the remaining ten coral species
and none of the extracts inhibited surface attachment of various
bacteria. Extrapolation of estimated surface concentrations
of the biologically active extract of M. digitata suggests
that the level of the growth inhibitory compounds may be sufficient
to deter microbial growth in situ.
Editor's Note:
The concept of the "coral
holobiont" now includes the coral animal, zooxanthellae
and symbiotic microbial flora. This study shows how coral
eggs preferentially act against certain microbes. It is an
important lesson to aquarists when mixing species and when
using any anti-microbial product to consider the implications
of shifts, possibly beneficial and possibly deleterious, to
the coral holobiont.
Invertebrate
Tidbits
Ronald
L. Shimek, Ph.D.
J.P. Aitken, R.K. O'Dor, and G.D. Jackson. 2005. The secret
life of the giant Australian cuttlefish Sepia apama
(Cephalopoda): Behaviour and energetics in nature revealed
through radio acoustic positioning and telemetry (RAPT). Journal
of Experimental Marine Biology and Ecology 320 (2005) 77-91.
Abstract:
Sepia apama were tagged with acoustic transmitters
and monitored on their native House Reef, Boston Bay, South
Australia, with a radio acoustic positioning telemetry (RAPT)
system. Cuttlefish were tagged with position-only and intramantle
jet pressure transmitters. New data analyses were developed
to handle problem data that arise with an uneven reef environment.
Maximum range for the cuttlefish varied from 90 m to 550 m.
Cuttlefish home range was between 5300 m2
and 23,700 m2. Sepia
apama were found to be diurnal as average distance traveled
was higher in the day than at night, and cuttlefish were active
for 32 days, but only 18 nights. After the cuttlefish settled
into reef crevices, activity spectrum and positioning analysis
showed foraging behaviour at only 3.7% per day and 2.1% per
night. Cuttlefish were found to spend more than 95% of the
day resting, which suggests that their bioenergetics are more
akin to those of octopus than of squid. The cuttlefish combination
of predator avoidance, efficient foraging and quiescent lifestyle
allows energy to be channeled into growth and fulfillment
of the live-fast-die-young cephalopod philosophy.
Editor's Note:
This article discusses the activity patterns found in the
Australian cuttlefish, Sepia
apama. Among other things, the article indicates that
for minimum, more-or-less normal behavior, one needs to provide
an immense amount of space, between 5,300 m2
(57,717 ft2) and 23,700
m2 (258,093 ft2)
for these animals. Although some aquarists attempt to keep
such large animals, it should seem apparent that confining
these relatively intelligent animals in the volume of a normal
aquarium is probably a good approximation of putting them
in a small prison cell and should not be done.
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