Science Notes & News by Eric Borneman & Ronald L. Shimek, Ph. D.

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.


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.


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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Science Notes & News by Eric Borneman & Ronald L. Shimek, Ph. D.-