Marine Invertebrates of Bermuda Greater star coral (Montastrea cavernosa) Bryant Jones with James B. Wood and Melissa Parr (Eds) Abstract Taxonomy  Habitat  Ecology  Recent Research  Commercial Importance  Bermuda Laws  Personal Interest  References  Links

Abstract


Montastrea cavernosa is a common hermatypic coral found in the tropical and subtropical waters of the Atlantic Ocean. It inhabits all reef environments, but is often the predominant coral in deeper zones. Tissue coloration is often green, brown, or reddish-orange and colonies form massive boulders or flat plates important for reef framework. M. cavernosa colonies have been most successful through asexual reproduction, although sexual reproduction occurs in annual cycles.

Taxonomy


Phylum: Cnidaria
  Class: Anthozoa
    Subclass: Hexacorallia
      Order: Scleractinia
        Family: Faviidae


Habitat


Montastrea cavernosa can be found in the tropical and sub–tropical waters of the Atlantic Ocean in all reef environments (Acosta and Zea, 1997; Sterrer, 1986). It is typically the predominant coral at depths ranging from 40 to 100 feet (Humann, 1993). Symbiotic zooxanthellae provide photosynthate to the coral as a primary source of energy for coral expansion and reproduction (Lasker, 1981). As depth increases, photosynthetic efficiency of M. cavernosa decreases in comparison to Porites astreiodes, Agaricia agricites, and Montastrea annularis, suggesting M. cavernosa feeds more at depths (Wyman et al. 1987).

Ecology


Montastrea cavernosa is a scleractinian coral important for reef building because it normally grows in large boulder-like formations (Humann, 1993). M. cavernosa can also grow in linear or encrusting formations in response to depth or light (Szmant, 1991). M. cavernosa normally appears with green, brown, and red pigmentations (Acosta and Zea, 1997). M. cavernosa captures and feeds on zooplankton through the use of sweeper tentacles, which extend from the polyp during feeding (Bak et al. 1982). Polyp expansion occurs during day and night, however it is more frequent at night when the verticle migration of zooplankton increase their concentrations (Lasker, 1979). Consumption of zooplankton provides nitrogen, phosphorus, and other essential nutrients (Sebens et al. 1996). Sweeper tentacles are imperative to M. cavernosa for both defense and aggression towards competing corals; space is limited space coral reefs (Bak et al. 1982). Tentacle movement provides Montastrea cavernosa with a potentially deadly attack on their neighbors; damage to competators from sweeping tentacles also enable collonies of Montastrea cavernosa to expand (Bak et al. 1982).

Scleractinian corals receive a significant amount of energy from their endosymbiotic zooxanthellae (Lasker, 1981). Photosynthate, organic matter, and other essential nutrients required for growth are transferred to the host coral by the zooxanthellae (Lasker, 1981). Zooxanthellae densities correlated with the feeding behavior of M. cavernosa (Lasker, 1981). Therefore if the polyps are feeding well, or are generally nocturnal, zooxanthellae densities are lower than in polyps that feed less frequently (Lasker, 1981).

Asexual reproduction, which occurs through budding and fragmentation, tends to be the most successful reproduction strategy for M. cavernosa (Szmant, 1991). Polyp positioning within the coral colony determines the reproductive success of individual polyps (Szmant, 1991). It is suggested that polyps located on the outer regions of colonies may not have the resources for sexual reproduction, while those polyps on the inner portions of colonies might be capable of several reproductive cycles (Szmant, 1991). M. cavernosa is a gonochoric species that exhibits an extensive oogenic cycle, and a shorter spermatogenic cycle. M. cavernosa’s oogenic cycle occurs throughout the year except for the few months following sexual reproduction (Szmant, 1991). M. cavernosa is a broadcasting species, which releases its gametes at night, approximately one week after the full moons, July through September (Acosta and Zea, 1997). Once eggs have been fertilized by sperm, the zygotes develop into planula larvae and settle on suitable substrate and metamoph into the ancester polyp. Colonies are then formed though asexual reproduction (Acosta and Zea, 1997).

Recent Research


Recent research involving M. cavernosa has been observed on coral diseases such as black band disease (BBD). BBD specifically infects large reef formation corals, which then significantly influences the geological and ecological structure of coral reefs (Frias-Lopez et al. 2003). It has recently been suggested that cyanobacteria, responsible for the tissue killing BBD, belong to at least three different taxa, rather than a single one as previously thought (Frias-Lopez et al. 2003). Through rRNA gene sequencing, new chains of cyanobacteria were identified as responsible for the BBD in corals from different locations within the Caribbean, as well as between the Indo-Pacific and Caribbean Seas (Frias-Lopez et al. 2003).

Although more research is needed, it does not appear that the presence of the cyanobacteria O. corallinae is coral species specific (Frias-Lopez et al. 2003). It was discovered two strains from the genus Phormidium are actually more closely related to the genus Oscillatoria, than to each other, and should be reclassified (Frias-Lopez et al. 2003). It is thought that the BBD cyanobacteria P. corallyticum is present in healthy corals that show no signs of BBD, however the algae is present in low frequencies (Frias-Lopez et al. 2003). Seawater surrounding the corals infected by BBD has also shown to contain high concentrations of O. corallinae suggesting its relation to the infected corals (Frias-Lopez et al. 2003).

Commercial Importance


Montastrea cavernosa is commercially important as it is part of Bermuda’s coral reefs and an attraction for tourism (Sterrer, 1986). M. cavernosa contributes to the structural formation of the reef and helps protect Bermuda against hurricanes and tropical storms by fading the intensity of wave action.

Bermuda Laws


Montastrea cavernosa is protected under the Coral Reef Preserves Act of 1966 (Laws of Bermuda). It is illegal to remove coral from this preserve or damage coral anywhere in Bermuda (Laws of Bermuda).

Personal Interest


I find Montastrea cavernosa personally interesting because of it's unique appearance while feeding. When this animal feeds, normally at night, it extends its sweeper tentacles in a beautiful array of symmetrical patterns (Bak et al. 1982). M. cavernosa is special in that it has an array of color displays, it can either appear green, brown, reddish, or grey and can be successful in the aquaria trade (Acosta and Zea, 1997).

It is suggested M. cavernosa should only be collected for the aquaria trade, if at all, in minimum quantities as they are hermatypic, or reef building, corals (Bruckner et al.). M. cavernosa has the potential to form massive coral colonies, so it is not recommended for the aquaria trade (Bruckner et al.) I would personally like to see M. cavernosa brought into the aquaria trade if, because as an aquarist myself, reproducing corals is quite an easy task once water quality is in balance. From personal diving experience, M. cavernosa is quite prevalent around the reefs of Bermuda, so removing small colonies in moderation would likely have little effect on the structure of the reef. Coral collection would have to be closely regulated because it is important juvenile populations remain high to replace the colonies that naturally perish. Many saltwater aquarium companies will accept coral colonies if they become too abundant in personal aquariums, and it is possible you may receive store credit towards other items in the store in return.

References

Acosta, A., Zea, S. 1997. Sexual reproduction of the reef coral Montastrea cavernosa (Sleractinia: Faviidae) in the Santa Marta area, Caribbean coast of Colombia. Marine Biology. Vol. 128; 141-148.

Bak, R.P.M., Termaat, R.M., Dekker, R. 1982. Complexity of coral interactions: influence of time, location of interaction and epifauna. Marine Biology. Vol. 69; 215-222.

Bak, R.P.M., Engel, M.S. 1979. Distribution, abundance and survival of juvenile hermatypic corals (scleractinia) and the importance of the life history strategies in the parent coral community. Marine Biology. Vol. 54; 341-352.

Bruckner, A. W., Borneman, E., Field, J. Coral community dynamics on coral reefs near Portsmouth, Dominica with recommendations for sustainable harvest practices and reef restoration strategies. Date accessed 11/13/07. http://www.ericborneman.com/Biographical/My%20writings/finalreportreefhealth.pdf

Frias-Lopez, J., Bonheyo, G.T., Jin, Q., Fouke, B.W. 2003. Cyanobacteria associated with coral black band disease in the Caribbean and Indo-Pacific Reefs. Applied and Environmental Microbiology. Vol. 69; 2409-2413.

Humann, Paul. 1993. Reef Coral Identification: Florida, Caribbean, Bahamas. Jacksonville, Florida: New World Publications, Inc. 86-116.

Lasker, H.R. 1979. Light dependent activities among reef corals: Montastrea cavernosa. Biological Bullentin. Vol. 156; 196-211.

Lasker, H.R. 1981. Phenotypic variation in the coral Montastrea cavernosa and its effects on colony energetic. Biological Bullentin. Vol. 160; 292-302.

Concepts, Maven. Laws of Bermuda. Coral Reef Preserves Act 1966. Date accessed 11/12/07 http://www.laws.gov.bm/

Sebens, K.P., Vandersall, K.S., Savina, L.A., Graham, K.R. 1996. Zooplankton capture by two scleractinian corals, Madracis mirabilis and Montastrea cavernosa, in a field enclosure. Marine Biology. Vol. 127; 303-317.

Sterrer, W. 1986. Marine Fauna and Flora of Bermuda: A systematic Guide to the Identification of Marine Organisms. New York: John Wiley and Sons.

Szmant, A.M. 1991. Sexual reproduction by the Caribbean reef corals Montastrea annularis and M. cavernosa. Marine Ecology Progress Series. Vol. 74; 13-25.

Wyman, K.D., Dubinsky, Z., Porter, J.W. and Falkowski, P.G. 1987. Light absorption and utilization among hermatypic corals: a study in Jamaica, West Indies. Marine Biology. Vol 96; 283-292.

Links

Center for Coastal Monitoring and Assessment (CCMA)
Coral Reefs
Growth and Survivorship of Stony Coral Meandrina meandrites and Montastrea cavernosa Transplants to an Artificial Reef Environment: A Work in Progress.