MEPS 312:113-121 (2006)  -  doi:10.3354/meps312113

Competition for space between encrusting excavating Caribbean sponges and other coral reef organisms

Mateo López-Victoria1,2, Sven Zea2,*, Ernesto Weil3

1Instituto de Investigaciones Marinas y Costeras – INVEMAR, and 2Departamento de Biología and Centro de Estudios en Ciencias del Mar, CECIMAR, Universidad Nacional de Colombia, INVEMAR, Cerro Punta de Betín, A.A. 1016, Santa Marta, Colombia
3Islas Magueyez Marine Laboratory, Department of Marine Sciences, University of Puerto Rico, PO Box 908, Lajas 00667, Puerto Rico
*Corresponding author. Email:

ABSTRACT: Encrusting and excavating Caribbean sponges Cliona aprica, C. caribbaea and C. tenuis (Hadromerida: Clionaidae) aggressively undermine and displace live coral tissue. To establish modes and rates of lateral advance into neighboring organisms, 171 sponge individuals were studied for 13 mo. Sponge advancement into live coral, via excavation underneath boundary polyps, occurred only when the 2 confronted at an angle of ≥180°. Sponges stopped or retreated when coral upward and inward growth at the boundary closed the angle between the coral and sponge, placing polyps out of reach of excavating tissue. At a straight angle of confrontation, C. tenuis advanced into coral at higher rates than the other 2 sponge species. Its advance was more pronounced into Diploria strigosa than into Siderastrea siderea. Sponge undermining continuously opened space for transient settlement of turf algae and for accumulation of sediments. Corallivory at the sponge–coral boundary did not imply greater rates of sponge advance, but probably did contribute to coral bioerosion. Massive corals escaped sponge undermining by upward growth, their ability to do so depended partly on defensive mechanisms. Foliose and platy corals escaped by overtopping. Rates of sponge advance into substrata incrusted and overgrown by algae were in general lower than into live coral, while sponges lost space to some encrusting invertebrates.

KEY WORDS: Competition · Excavating sponges · Cliona · Coral reefs · Caribbean · Corallivory · Turf algae · Reflex angle

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