The Life Cycle of a Coral Killer: the Acropora-Eating Flatworm

Open Access
DOI: 10.18258/1621
Funded on 1/08/14
Successfully Funded
  • $6,211
  • 120%
  • Funded
    on 1/08/14

About This Project

The Acropora-eating flatworm is a destructive predator of Acropora corals in aquariums. This research aims to uncover some key questions on the life cycle of this polyclad flatworm in order to develop a scientifically-based protocol for its control.

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What is the context of this research?

The Acropora-eating flatworm (AEFW) is new to science but it has been a significant pest to the tropical marine aquarium community for over a decade. It is found in reef tanks around the world and can rapidly eat and destroy valuable Acropora corals. In order to control this pest we aim to answer some fundamental questions about its life cycle.

  1. How long does it take for the eggs to hatch?
  2. Do they hatch as larvae or juveniles, or both?
  3. How long does it take for the worms to reach sexual maturity?
  4. How long can the newly hatched worms survive without food?
  5. How long can the adults survive without food?
To answer these questions we will carry out replicated experiments and quantify the variation.

What is the significance of this project?

Acropora corals are among the most popular stony corals collected for the global aquarium trade and the emerging trade of cultivated corals is beginning to relieve the pressures that conventional coral collection has placed on wild stocks. The Acropora-eating flatworm (AEFW) is small and has perfect camouflage against its coral host, because of this they are easily, and inadvertently, introduced into reef tank systems. In this environment they thrive (possibly due to the absence of a natural predator) with devastating consequences for the Acropora colonies.

The AEFW shows many interesting ecological, evolutionary and developmental adaptations to corallivory. For example, initial observations have shown that it develops via a larval stage, though its dispersal potential is limited as it undergoes metamorphosis inside the egg capsule – a possible mechanism to ensure retention of juveniles on a food source.
Understanding more about its life cycle, such as whether they can hatch earlier as dispersive larvae, is important in controlling their populations and mitigating their impact in closed aquarium systems. This research therefore is important for coral husbandry and the conservation of these corals.

What are the goals of the project?

Using the data from these experiments we will develop a protocol that will advise coral aquarists and hobbyists on how long to keep their tanks free of Acropora (in order to starve any remaining worms). We will also be able to say whether or not the AEFW can travel (as microscopic larvae) to other tanks that share the same water and a common sump.
This is the first step in controlling this pest, the next step is then to find a way to control them in-tank without having to remove the corals and put them through a series of chemical dips. We are optimistic that these initials experiments will give us some insights into how to proceed to this next step.

While developing the definitive protocol on AEFW control, we will also give regular updates to donors on the results of these experiments as they come in. We will pass on any interesting observations we make on the AEFW and we hope to get your feedback and ideas.

Update: Any funds raised above our original goal will go towards sequencing the messenger RNA (mRNA) of the AEFW.Sequencing the mRNA will allow us to identify the genes that are regulating the metabolism and development of this animal, and could provide putative targets for in-tank treatments (i.e. using reagents that can target and disrupt the activity of AEFW-specific genes).


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This research will be performed in Houston, Texas in collaboration with Cat Dybala (president of the Marine Aquarium and Reef Society of Houston- MARSH) who has set up dedicated tank systems for the study of the Acropora-eating flatworm. We will use the funds raised through Microryza to cover the costs of equipment and consumables for the experiments: tanks, corals, chemical reagents, and overheads. This money will also fund a return airfare to Houston, accommodation and car rental.

Meet the Team

Kate Rawlinson
Kate Rawlinson
Cat Dybala
Cat Dybala

Team Bio

Kate Rawlinson - I am a marine biologist researching flatworms ( The Acropora-eating flatworm (AEFW) was bought to my attention in 2009 and we have since described it as a new species. Collaborating with the reef hobbyist community is helping advance our understanding of the biology of these ecologically and economically important worms. We aim to use this information to develop strategies to effectively manage (and prevent) AEFW infestations.

Cat Dybala - I am an avid reef hobbyist and the current president of the Marine Aquarium and Reef Society of Houston (MARSH). My interest in AEFW began when I inadvertently received them on Acropora frags. I realized how little we know about them despite hobbyists having lost tens of thousands of corals to them over the years. I am deliberately culturing them to shed light on their biology in order to find better ways to control and eradicate them in home aquariums.

Cat Dybala

I am an avid reef hobbyist. I've been keeping aquariums for over 5 years and am the current president of the Marine Aquarium and Reef Society of Houston (MARSH). I currently keep a 150 gallon LPS and SPS reef and a 90 gallon tank dedicated to macroalgae. Some of my key interests include marine fish breeding, captive growth and propagation of corals, DIY projects of any kind, and the collection of rare macroalgae. I am also a professional photographer and photographic artist.

Press and Media

Mr Saltwater Tank is donating 10% of the proceeds of his pre-Christmas sale of Saltwater Tank Guides to support this project. Buy these ultimate no-nonsense guides and support this project simultaneously at

Additional Information

Rawlinson KA and Stella JS (2012) Discovery of the Corallivorous Polyclad Flatworm, Amakusaplana acroporae, on the Great Barrier Reef, Australia – the First Report from the Wild. PLoS ONE 7(8): e42240.

Rawlinson KA, Gillis JA, Billings RE, Borneman EH (2011) Taxonomy and life history of the Acropora-eating polyclad flatworm: Amakusaplana acroporae nov. sp. (Polycladida, Prosthiostomidae) Coral Reefs. 30:693-705.

Kate's flatworm research website:

Project Backers

  • 71Backers
  • 120%Funded
  • $6,211Total Donations
  • $87.48Average Donation
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