1. Identifying AGRRA Corals: Part 3 Plates and Other Agariciids
Judith Lang and Kenneth Marks
Atlantic and Gulf Rapid Reef Assessment (AGRRA) Program
Revision:
© K. Marks
© K. Marks
© K. Marks 1

2. For images used in Part 3, our special thanks to:
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 3, our special thanks to:
P. Humann, M. Nugues, D. Petersen, R. Steneck, G. van Moorsel (ecosub.nl) 2

3. Reminder: What to Look for Underwater
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
Polyp colour – brown, tan, yellow, olive, green, red
Septal shape – fat, thin; smooth, toothed
Reminder: What to Look for Underwater

4. Reminder: AGRRA Coral Species
The stony corals illustrated here are limited to species found in the wider Caribbean at depths (<20 m) typical of most AGRRA surveys.
The names of some of these corals are changing as a result of modern research. More taxa are added as we gain underwater photographs of species that are rare and/or of geographically limited distributions. Expect periodic updates!
Photographers who can enhance this collection are encouraged to contact Judy Lang at: or
For each species: (# in m and ft) = maximum colony size
Reminder: AGRRA Coral Species

5. Coding Corals in AGRRA Surveys
Use the CARICOMP-based coral codes.
The coral code for a genus (or occasionally a species complex) is the first 4 letters of its genus name and should be used whenever you are unsure of a coral’s species identity: AGAR = Agaricia
The coral code for a species is the first letter of the genus name followed by the first 3 letters of its species name: ALAM = Agaricia lamarcki
Codes are shown before names appear on the introductory slide for species that are commonly recorded in AGRRA surveys.

6. Agariciid Corals
small polyps; meandroid colonies (polyp mouths in valleys, between ridges)
© K. Marks
Helioseris
thick, wide
discontinous ridges
Agaricia
thick, wide ridges
Undaria
thin, pointed ridges
unifacial and platy only
narrow valleys are
short and/or long
unifacial or bifacial
platy or massive
wide, shallow, long valleys
wide, short valleys or individual polyps
© K. Marks

7. Some species of Agaricia (agaricites, tenuifolia, humilis) were reclassified as species of Undaria on the basis of morphological characters. See Budd et al., 1994 (reference given on final slide).
More recent molecular analyses may result in a future reversal of this designation (J. Stake, pers. comm., Sept. 2011).

8. Undaria agaricites UAGA
© K. Marks
Close-up
UAGA
small polyps in long rows
or short reticulations
pointed ridge tops
tan to many shades of brown; some fluoresce pink or orange
© M. Nugues

9. Undaria agaricites UAGA
examples of variation in shape:
unifacial - crusts, plates, low mounds
bifacial - mounds with keels or thick lobes
(to ~ 1 m/3 ft)
© K. Marks 9

10. Undaria agaricites UAGA
many colonies may settle and grow close together
© P. Humann

11. Undaria tenuifolia UTEN
thin, vertical keels are elongate or dissected
small polyps in long rows or short reticulations
yellowish, grey or brown
large (to ~ 4 m/12 ft)
UTEN
© K. Marks
© K. Marks

12. Undaria tenuifolia UTEN
© R. Steneck
How differs from keeled U. agaricites:
much thinner keels, colonies are much larger when fully grown

13. Which is Which? U. agaricites U. tenuifolia UAGA UTEN © K. Marks
© R. Steneck
Which is Which?
© K. Marks
U. agaricites U. tenuifolia
UAGA UTEN

14. Complications! Some keeled colonies of
U. agaricites closely resemble small
U. tenuifolia.
If unsure of species identity, code as:
Undaria UNDA

15. Undaria humilis UHUM tiny, densely packed, polyps with deep centers
reticulate ridges have pointed tips
yellowish to dark brown
small crusts (to ~ 12 cm/5 in)
© D. Petersen
UHUM
© G. van Moorsel
Close-up
UHUM 15

16. Undaria humilis UHUM How differs from U. agaricites:
polyps are smaller, more densely packed, have deeper centers
crusts don’t develop
platy edges
colonies are smaller when fully grown
Undaria humilis UHUM
Close-up
© G. van Moorsel

17. Which is Which? U. agaricites U. humilis UAGA UHUM Close-up
© G. van Moorsel
U. agaricites U. humilis
UAGA UHUM

18. Complications! Some small colonies of
U. agaricites closely resemble U. humilis.
If unsure of species identity, code as:
Undaria UNDA

19. Agaricia fragilis AFRA
© K. Marks
AFRA
tiny polyps with low ridges in long rows that are sometimes contorted and have relatively few, if any, reticulations
tan, yellow- to dark- brown;
can have bright colours and/or polyps that lack zooxanthellae
thin plates
(to ~ 15 cm/6 in)

20. Agaricia fragilis AFRA
Close-up
expanded polyps
contracted polyps
polyps may be sunken and appear constricted
Agaricia fragilis AFRA
© G. van Moorsel

21. Agaricia fragilis AFRA
How differs from all
U. humilis and U. agaricites:
thicker ridges have few, if any, reticulations
thinner skeletons
+ from platy U. agaricites:
smaller polyps, and colonies are smaller when fully grown
© K. Marks
Agaricia fragilis AFRA
© K. Marks
© P. Humann
© P. Humann

22. Which is Which? A. fragilis U. agaricites U. humilis AFRA UAGA UHUM 22
© K. Marks
© P.Humann
A. fragilis U. agaricites U. humilis
AFRA UAGA UHUM 22

23. Agaricia lamarcki ALAM
© P. Humann
Close-up
© K. Marks
polyps with conspicuous, white mouths in long rows or shorter reticulations
thick ridges with broad, rounded or somewhat pointed tops
yellow- to dark- brown
thick, heavy plates
(to ~ 2 m/6 ft)

24. Agaricia lamarcki ALAM
How differs from
A. fragilis and
platy U. agaricites:
larger polyps
thicker, denser skeletons
colonies are larger when fully grown
+ from U. agaricites:
polyp mouths more distinct
© K. Marks

25. Which is Which?
© M. Nugues
A. lamarcki U. agaricites
ALAM UAGA

26. Helioseris cucullata HCUC*
*HCUC was considered a species
of Leptoseris for several decades.
© K. Marks
HCUC*
Close-up
outward-facing polyp mouths at the bases of steep, thick ridges of variable length
conspicuous septa

27. Helioseris cucullata HCUC
© K. Marks
tan, yellow-brown, brown; may fluoresce greenish, blue or grey colours
very thin plates
(to ~ 2 m/6 ft)

28. Helioseris cucullata HCUC
How differs from A. fragilis:
larger polyps
higher ridges
+ from platy U. agaricites:
polyp mouths at bases of steep, thick, outward-facing ridges
thinner plates
© K. Marks
partially bleached HCUC

29. Which is Which?
© P. Humann
H. cucullata U. agaricites
HCUC UAGA 29

30. Which is Which?
© K. Marks
A. fragilis H. cucullata
AFRA HCUC 30

31. Reference
Budd, A.F., T.A. Stemann, and K.G. Johnson Stratigraphic distribution of genera and species of Neogene to Recent Caribbean reef corals. Journal of Paleontology 68: