Heart of glass: spicule armament and physical defense in temperate reef sponges

Autor: Adrian M. Ferguson, Andrew R. Davis
Rok vydání: 2008
Předmět:
Zdroj: Marine Ecology Progress Series. 372:77-86
ISSN: 1616-1599
0171-8630
DOI: 10.3354/meps07680
Popis: Siliceous inclusions play an important role in deterring terrestrial herbivores, but their role in marine systems remains controversial. Sponges are ubiquitous members of marine benthic communities and represent a potentially valuable food source for many predatory species, yet they have few natural predators. An in situ method was used to assess the deterrent effects of siliceous spicules or whole sponge skeleton, which were hypothesised to act as a physical defense in temper- ate reef sponges. Natural concentrations of spicules from 5 species of sponge and the spongin skele- ton from a sixth species were incorporated into artificial diets, which were similar in nutritional qual- ity to the sponge tissues. These were offered to the sea urchin Centrostephanus rodgersii in feeding choice experiments including control discs containing no spicules or spongin skeleton. Spicules from 4 species, Tedania anhelans, Clathria pyramida, Chondrilla australiensis and Chondrilla sp., deterred feeding by C. rodgersii. Spicules from a fifth species, Callyspongia sp., and intact skeleton isolated from Cacospongia sp., failed to deter C. rodgersii. This is the first demonstration of antifeedant activ- ity associated with skeletal elements against sea urchins. Importantly, unlike previous work in the tropics, very small spicules (microscleres) measuring
Databáze: OpenAIRE