Welcome to the Plerogyra genus landing page. In this section, you will find general information about this genus and tips on how to identify it. If you are looking to confirm an observation made with the Coral Finder, use the image browser below to identify a structure or growth stage similar to what you saw underwater. Then choose one of the following links for further information on similar genera: large day-time extended polyps, or juvenile Plerogyra.
- 3 species
- Coral Finder p. 6c, 26, 27
- COTW – Vol 2 p. 68-81
Found in the Indo-Pacific.
Juvenile Plerogyra appear solitary but grow into mound-like colonies with age. These colonies are uncommon and may be found in protected areas.
The corallites grow on short tubes (phaceloid) or in meandering valleys with separate walls (flabello-meandroid). The septa and walls are thick and smooth, but are generally hidden; during the day grape-like bubbles (vesicles), and at night tentacles are extended. The shape of the vesicles allows species level identification.
The large day-time expanded polyps and thick, smooth septa are characteristic of the Euphyllidae.
(slide show with photos of tentacles and when vesicles extended.)
The Coral Finder lists Plerogyra in two key groups with Euphyllia and Physogyra being candidates for confusion.
Similar genera to Plerogyra with large daytime expanded polyps (Coral Finder p27)
Plerogyra can be confused with Physogyra but they may be easily separated by examining the corallite arrangement; Plerogyra forms valleys with separate walls, whereas Physogyra’s valleys have shared walls. If these structures are hidden by vesicles, waft your hand over the colony; Plerogyra’s vesicles will retract slowly, whereas those of Physogyra will retract more rapidly, exposing the colony surface.
Similar genus: Physogyra
Juvenile Plerogyra can be difficult to differentiate from Euphyllia. However the grape-like vesicles of Plerogyra are only expanded during the day, whereas the tentacles are extended at night. Tentacles of Euphyllia are extended day and night.
Similar genus: Euphyllia
- Euphyllidae family page
Suggested Reading – Identification Tools
- Veron, J. E. N. (1985). Corals of Australia and the Indo-Pacific. Sydney: Angus and Robertson.
- Veron, J. E. N. (2000). Corals of the World. Melbourne: Australian Institute of Marine Science.
- Veron, J. E. N. (2002). New species described in ‘Corals of the World’: Australian Institute of Marine Science.
- Veron, J. E. N., & Pichon, M. (1980). Scleractinia of Eastern Australia. Part 3, Families Agaraciidae, Siderastreidae, Fungiidae, Oculinidae, Merulinidae, Mussidae, Pectiniidae, Carophylliidae, Dendrophylliidae. Australian Institute of Marine Science Monograph Series, IV, 471.
Suggested Reading – Other Topics
- Fricke, H., & Vareschi, E. (1982). A scleractinian coral (Plerogyra sinuosa) with photosynthetic organs. Marine Ecology-Progress Series, 7(3), 273-278.
- Vareschi, E., & Fricke, H. (1986). Light responses of a scleractinian coral (Plerogyra sinuosa). Marine Biology, 90(3), 395-402.