What are the most widespread coral parasites and localized predators, and what impact do they have on coral reefs? Rachael L. Shearouse

background Parasitism: a type of symbiotic relationship between two organisms in which one species lives on or in another, drawing nourishment from that species at its expense Localized predator: a predator who only feeds on prey within a certain area

Most widespread Parasites and Localized Predators Parasitic Bivalves: Lithophaga L. simplex Fungiacava Localized Predators: Coralliophila C. violacea C. abbreviata Hermodice carunculata

Lithophaga simplex Inhabits the scleractinian coral, Astreopora myriophtholma, in high density Consumes large amounts of coral, leaving hollow coral skeletons May have a slight mutualistic relationship (Mokady 1998)

Lithophaga and Fungiacava Both geneses have restricted feeding to live corals Each species displays host-specificity preventing competition for the same host Increases reef destruction Causes bioerosion

Coralliophila violacea Outbreaks of 2 to 100’s of snails on a single coral Leave white “scars” which serve as entrances for boring organisms Weaken entire reef Localized tissue damage on margins and interior of reef Cause large surface injuries in the interior of the colony Cause the development of new energy sinks in the interior of the reef Feed on coral by sucking with proboscis (Oren 1998)

Coralliophila abbreviata The coral Acropora palmata is declining with little signs of recovery in the Caribbean Lack of survival is due largely to predation by C. abbreviata C. abbreviata causes coral colonies to become remnant colonies C. abbreviata has the potential to inhibit the recover of A. palmata populations (Grober-Dunsmore 2006)

Hermodice carunculata Vibrio shiloi is the causative agent of bleaching in the coral Oculina patagonica V. shiloi can not live on coral in temperatures lower then 20 ۫ C H. carunculata acts as a winter reservoir V. shiloi reproduces inside H. carunculata When temperatures rise V. shiloi causes mass bleaching events (Sussman 2003)

Hermodice carunculata Fireworm predation causes permanent damage to milleporid hydrocorals The open space created by fireworms is then colonized by algae 97% of the bare space caused by fireworm feeding was colonized by algae a month later Consumption of M. complanta by H. carunculata sufficiently limits coral growth and recovery (Witman 1988)

Overall Impacts Localized coral tissue damage Large rates of coral consumption Bioerosion: breakdown of coral reef structure Cause secondary mortality after hurricanes and other tropical storms Spread coral diseases

Possible Solutions Restore coral reef trophic levels Reintroduce predators that feed on these coral parasites and localized coral predators Reduce over fishing to bring back natural predators Marine Protected Areas

Works Cited Grober-Dunsmore, R., Bonito, V., and Frazer, TK Potential inhibitors to recovery of Acropora palmata populations in St. John, US Virgin Islands. Marine Ecology-Progress Series 321: Johnston, L. and Miller, MW Variation in life-history traits of the corallivorous gastropod Coralliophila abbreviata on three coral hosts. Marine Biology 150: Kleemann, Karl Associations of coral and boring bivalves: Lizard Island (Great Barrier Reef, Australia) versus Safaga (North Red Sea). Beitraege zur Palaeontologie 20: Kleemann, KH Boring bivalves and their host corals from the Great Barrier Reef. Journal of Molluscan Studies 46: Mokady, O., Y. Loya and B. Lazar Ammonium contribution from boring bivalves to their coral host- a mutualistic symbiosis? Marine Ecology Progress Series 169: Nybakken, James W. and Mark D. Bertness. Marine Biology: An Ecological Approach Sixth Edition. Pearson Benjamin Cummings, Inc. San Francisco, CA Oren, U., Brickner and Y. Loya Prudent sessile feeding by the corallivore snail Coralliophila violacea on coral energy sinks. Proc. R. Soc. Lond. B 265: Sussman, M., Loya, Y., Fine, M., and Rosenberg, E The marine fireworm Hermodice carunculata is a winter reservoir and spring-summer vector for the coral bleaching pathogen Vibrio shiloi. Environmental Microbiology 5: Witman, JD Effects of predation by the fireworm Hermodice carunculata on milleporid hydrocorals. Bulletin of Marine Science 42: