The occurrence of corallimorpharians (naked corals)

Daphne G. Fautin

Department of Ecology and Evolutionary Biology and Natural History Museum

University of KansasLawrence, Kansas 66045, USA

John M. GuinotteMarine Conservation Biology Institute

2122 112th Ave NE, Suite B-300Bellevue, Washington 98004, USA

CORALLIMORPHARIA

DIVERSITY• 1631 valid species of Scleractinia

• 55 valid species of Corallimorpharia

• 1112 valid species of Actiniaria

• Members of all taxa occur throughout the world’s oceans

PHYLOGENETIC RELATIONSHIPS

to compare the depth distribution of deep-sea corallimorpharians with that of deep-sea scleractinians

OBJECTIVE

to infer if CaCO3 concentration may be relevant to the occurrence of these animals that are so similar except for the skeleton

http://hercules.kgs.ku.edu/Hexacoral/Anemone2

DATA: general surveys rather than those for the target organisms

and US Antarctic Program

The Challenger Expedition

Challenger Scleractinia Corallimorpharia

Species 98 (91 to species) 3(in 41 genera) (All Corallimorphus)

Stations 70 6(Both occurred at 3 stations)

Depth range 18-5304 m 2515-3950 m

Average depth 1439 m 3142 m

p = 0.000201 t-test 1-tailed, unequal variance

Antarctic Scleractinia Corallimorpharia

Species 38 (37 to species) 2(in 19 genera) (Both Corallimorphus)

Stations 190 12(Both occurred at 8 stations)

Depth range 9-4840 m 132-4410 m

Average depth 676 m 1600 m

p = 0.019613 t-test 1-tailed, unequal variance

COMPARISONS between Antarctic and Challenger data

• Antarctic lower diversity in both taxa

• Twice as many stations in Antarctic

• Average Antarctic depth about half that of Challenger for both taxa

• In Antarctica, depth range of Scleractinia slightly shallower, that of Corallimorpharia considerably shallower and deeper

Yet average depth of corallimorpharians significantly deeper in both datasets

CaCO3 concentration: proportion deeper than

aragonite saturation horizon (1995) Scleractinia Corallimorpharia

Challenger stations 18/40 (45%) 5/5 (100%) species 19/98 (19%) 3/3 (100%)

(in 10/41 genera)

Antarctic stations 29/122 (24%) 5/10 (50%) species 16/38 (42%) 2/2 (100%)

(in 9/19 genera)

IMPLICATIONS

Fine and Tchernov. 2007. Science.Scleractinian coral species survive and

recover from decalcification.

These “naked” polyps are indistinguishable from corallimorpharians

“Polyp bail-out”: under stress (including in aquaria), scleractinians can crawl out of their skeletons.

IMPLICATIONS

THE FUTURE??

and/or

Shallower scleractinians

More corallimorpharian species

ACKNOWLEDGMENTS• Funding was provided by US National Science

Foundation grants DEB95-21819 and DEB99-78106 (in the program PEET - Partnerships to Enhance Expertise in Taxonomy), grant OCE 00-03970, and grant EF-0531779 (in the program Assembling the Tree of Life).

• Sukeerthi Bokka for assembling data• Matthew Jones for photo of corallimorpharian

• James C Orr for CaCO3 concentration data