Identifying AGRRA Corals: Part 1Identifying AGRRA Corals: Part 1Mound and Boulder CoralsMound and Boulder Corals

Judith Lang and Kenneth MarksJudith Lang and Kenneth MarksAtlantic and Gulf Rapid Reef Assessment (AGRRA) ProgramAtlantic and Gulf Rapid Reef Assessment (AGRRA) Program

Revision: 2012-03-09Revision: 2012-03-09 www.agrra.orgwww.agrra.org

The following images are Copyright ©by New World Publications

and by other photographers.

Permission is granted to use the photographs and slides in this presentation with the

AGRRA Program and, with attribution, for other valid educational purposes..

All other uses are strictly prohibited.

For images used in Part 1, our special thanks to:P. Humann, B. Kakuk, R. McCall, C. Rogers, C. Sheppard, E. Shinn, R. Steneck, T. Turner

Stony Corals

Stony corals have soft polyps above a stony (calcareous) skeleton. Most reef-building corals form colonies of interconnected polyps.

The shapes, sizes and colour of the polyps and colonies are used to help identify corals.

expanded polypsexpanded polyps

partially contracted polypspartially contracted polyps

The shapes and sizes of polyps are also visible in their underlying skeletons.

Septa areconspicuous vertical partitions in the polyp wall.

Coral Skeletons

separated polyps interconnected polyps

Adapted from P.R. Kramer

Colony shape – massive (= mound, columnar, heavy plates), crust, plate, branching

Colony size range – small to big

Colony surface – bumpy, smooth, ridged

Polyp size – small to big

Polyp shape – round, elliptical, irregular, Y-shaped, meandroid (= short or long ridges and valleys)

Polyp colour – brown, tan, yellow, olive, green, redSeptal shape – fat, thin; smooth, toothed

What to Look for Underwater

The stony corals illustrated here are limited to species that are found in the wider Caribbean at depths (<20 m) that are typical of most AGRRA surveys.

The names of some corals are changing as a result of modern research. Expect updates!

For each species:(number in m and ft = maximum colony size)

AGRRA Coral Species

Coding Corals in AGRRA Surveys

Use the CARICOMP-based coral codes.

The coral code for a genus is the first 4 letters of its genus name.

ACRO = AcroporaUse the genus code whenever you are unsure of a coral’s species identity.

The coral code for a species is the first letter of the genus name followed by the first 3 letters of its species name.

APAL = Acropora palmata

Montastraea faveolata MFAV

small round polyps

mounds with “skirted” (platy) edges, or thick plates

diverse colours: green, brown, grey

can grow very large (to ~ 4-5 m/12-15 ft)

Montastraea faveolata MFAV

surfaces smooth, ridged or with bumps aligned in vertical rows

mounds flatten when shaded or in deeper water

shallow/high light

deep/low light

Montastraea annularis MANN

small round polyps that are alive at the tops of columns

form plates at colony bases under low light conditions

often light brown or yellow-brown

large (to ~ 3-4 m/9-12 ft)

Montastraea annularis MANN

How differs from M. faveolata:subdivides to form columns, with basal plates under low light conditions

live polyps on column tops lack a skirt-like edge

lighter tissue colours

Montastraea franksi MFRA

© P. Humann

irregular bumps with large polyps that are pale or lack zooxanthellae (can see skeleton below)

large polyps along colony margin

aggressive spatial competitor

Montastraea franksi MFRAdeep/low light:

thick, lumpy platesshallow/high light: irregularly shaped

mounds

can grow quite large (to ~ 3-4 m/9-12 ft)

How similar to M. faveolata:have bumps on large mounds, crusts or thick plates

How differs:larger polyps overall

polyps on bumps are even bigger, irregularly shaped, and often lack zooxanthellae

a more aggressive spatial competitor

Montastraea franksi MFRA

How similar to M. annularis: can have large columns or thick plates

How different:enlarged polyps in irregular bumps can lack zooxanthellae

large polyps along growing margins

a more aggressive spatial competitor

Montastraea franksi MFRA

Which is Which?

M. annularis M. franksi M. faveolata MANN MFRA MFAV

Complications!

Some colonies look like “intermediates” ofM. franksi, M. annularis and M. faveolata.

If unsure of species identity, code as Montastraea MONT

“In general, the genetic and morphological data suggest a north to south* hybridization gradient, with evidence for introgression strongest in the north. However, reproductive data show no such trend, with intrinsic barriers to gene flow comparable or stronger in the north.”

Fukami et al. (2004) Evolution 58:324-337.

*north to south = Bahamas versus Panama

Solenastrea bournoni SBOU

1 m

small round polyps with protruding walls (“outies”)

polyp centers are slightly darker than the outer walls

smooth or irregularly shaped mounds

(usually to ~ 50 cm/20 in)

Solenastrea bournoni SBOU

How differs from M. franksi:bumps on mounds lack enlarged, colourless polyps

lighter colours; central areas of polyps are darker than the outer walls

smaller colonies

M. franksi S. bournoni MFRA SBOU

Which is Which?

Solenastrea hyades SHYA

How similar to S. bournoni:light colourspolyps with distinct walls(to ~ 60 cm/2 ft)

How differs:irregular lobes abovean encrusting base

Montastraea cavernosa MCAV

large, round, distinct polyps (“outies”)

brown, yellow-brown, green or grey

pink or orange fluorescence sometimesseen underwater is due to a photosynthetic cyanobacterium (blue-green alga) in the polyps

Montastraea cavernosa MCAV

shallow/high light: mounds or columns

(to ~ 3 m/9 ft)

Montastraea cavernosa MCAV

deep/low light: flattened, massive plates or crusts

Dichocoenia stokesi DSTO

protruding, round, elliptical, elongate, or Y-shaped polyps

cream, yellow, or brown

mounds or irregular shapes

(to 50 cm/18 in)

Dichocoenia stokesi DSTO

How differs from M. cavernosa:polyps are more separate, andround, elliptical, Y-shaped, or sometimes very elongate

septa on vertical (not sloping) walls are more distinct

smaller colonies

Dichocoenia DICHColonies with flattened plates, and many small round polyps, were previously called Dichocoenia stellaris.

Their identity, and that of columnar or irregularly shaped “intermediates” with flattened bases, is unclear.

Favia fragum FFRA

distinct, round-elongated polyps (some Y-shaped)

septa have small teeth (see next slide)

pale yellow to brown

small (usually to ~ 10 cm/4 in)

Favia fragum FFRA

How similar to D. stokesi:distinct, round-elongated polyps, some are Y-shaped

How differs:polyp walls protrude far less

polyps are less separate

thinner septa with teeth on summits and inner sides

smaller when fully grown

D. stokesi M. cavernosa F. fragum DSTO MCAV FRA

Which is Which?

Siderastrea siderea SSID

sunken polyps (“innies”)

thin septa

uniform colours

large mounds (to ~ 2 m/6 ft)

Siderastrea siderea SSID

some pale or bleached colonies are fluorescent

Siderastrea radians SRAD

sunken “pinched” polyps (“innies”)

thick septa

pale polyp walls, centers dark

crusts, low mounds or unattached nodules

small (to ~ 30 cm/12 in)

Siderastrea radians SRAD

How differs from S. siderea:septa are fewer and thicker

“pinched” polyps, some elongate, and with darker centers

smaller, flatter colonies

S. siderea S. radians SSID SRAD

Which is Which?

Stephanocoenia intersepta SINT

SINTSINTSINTSINT

SINTSINT

round, sunken polyps thick septa

brown colour is most intense in polyp centers; appear to “blush” when polyps contract

thick crusts, irregular mounds

(to ~ 1 m/3 ft)

Stephanocoenia intersepta SINTHow similar to Solenastrea bournoni:small, round polyps with light colours that are most intense in polyp centers

How differs:sunken (not protuberant) polyps

crusts and low mounds usually have smoother surfaces

Stephanocoenia intersepta SINT

How similar to Siderastrea radians:sunken polyps with dark polyp centers

How differs:“blushes” when tissues contract

no “pinched” polyps

larger crusts and mounds

S. intersepta S.radians S. bournoni SINT SRAD SBOU

Which is Which?

Porites astreoides PAST

shallow: usually lumpy mounds and yellow, yellow-green or olive

deep: usually thick crusts, lumpy or flattened plates and grey or brown

(usually to ~ 1 m/3 ft)

all depths: tall, thin polyps look “fuzzy” when expanded

“unusual” shape/colour combinations can occur

Porites astreoides PAST