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ECHINOID DISTRIBUTION AND HABITS, KEY 

 LARGO CORAL REEF PRESERVE, FLORIDA 



By 



Porter M. Kier, U. S. National Museum, Smithsonian Institution, and 

 Richard E. Grant, U. S. Geological Survey, Washington, D. C. 



(With 16 Plates) 



ABSTRACT 



Seventeen species of echinoids were found between the shore and a 

 depth of 110 feet seaward from the living reef. All but one were 

 encountered alive, and observed in their habitats. Eucidaris tribu- 

 loides (Lamarck) is solitary, widely and sparsely distributed in rocky 

 niches and turtle grass. Echinometra lucunter (Linnaeus) is abundant 

 in rock niches just below low tide, and less abundant in isolated 

 clumps of coral and sponge on sand. E. viridis Agassiz is less abun- 

 dant in the same habitats, and extends to greater depth on the reef. 

 Arbacia punctulata (Lamarck) similarly inhibits rocky niches along 

 the shore, and also clusters near sponges and corals elsewhere. 

 Diadema antillarum Phillipi is ubiquitous, living at all observed depths 

 in rocky niches along the shore and on the reef, in large flocks in 

 turtle grass, but not on clean sand. Astropyga magnified Clark moves 

 in groups over open sand areas at relatively greater depth. Lyt echinus 

 variegatus (Lamarck) and Tripneustes ventricosus (Lamarck) oc- 

 cupy similar habitats in turtle grass, although L. variegatus is more 

 abundant and its habitat includes rocky areas near shore. 



The sand dollars Leodia sexiesperforata (Leske) and Encope 

 michelini Agassiz burrow through the uppermost inch of sand, and 

 are absent from rocky or grassy areas. Similarly, Clypeaster sub- 

 depressus (Gray) burrows through the upper part of the substrate, 

 or occasionally merely covers itself with sand and shell debris and 

 moves along the surface of the sand. The latter mode of life is normal 

 for Clypeaster rosaceus (Linnaeus) which never was seen to burrow 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 149, NO. 6 



