Hallock,-P.  Interoceanic differences in foraminifera with 
	symbiotic algae: A result of nutrient supplies?  
	PROCEEDINGS-OF-THE-SIXTH-INTERNATIONAL-CORAL-REEF-
	SYMPOSIUM,-TOWNSVILLE,-AUSTRALIA,-8th-12th-AUGUST-1988.-
	VOLUME-3:-CONTRIBUTED-PAPERS-MINI-SYMPOSIUM-11-16-TO-22. 
	Choat,-J.H.;Barnes,-D.;Borowitzka,-M.A.;Coll,-
	J.C.;Davies,-P.J.;Flood,-P.;Hatcher,-B.G.;Hopley,-D.;et-
	al.-eds.. 1988. pp. 251-255.

Symbiont-bearing benthic foraminifera, belonging to 2 
different suborders, are commonly found on coral reefs and in 
reef-associated environments. Interoceanic comparisons of 
members of the 2 suborders provide striking differences. 
Symbiont-bearing rotaliines have diversified "vertically" in 
the Pacific, i.e., show depth zonation, while the few 
Atlantic forms are simple and unspecialized. Symbiont-bearing 
milioline taxa are numerically comparable between the 2 
regions. These protists, with their relatively more opaque 
tests and greater variety of taxa of algal symbionts, appear 
to be restricted to shallower, higher light environments. 
They have diversified "horizontally" into backreef, lagoonal 
and upper slope habitats. Subtropical gyres of the larger 
Pacific, remote from the influences of upwelling and runoff, 
have provided oligotrophic habitats necessary for the 
development and persistence of vertical zonation exhibited by 
rotaliine foraminifera with algal symbionts.