Summary
Physical Description
Ecology
Life History & Behaviour
Reproduction
Experiment: Cell Aggregation
Nutrition
Anatomy & Physiology
Evolution & Systematics
Biogeographic Distribution
Conservation & Threats
References & Links | NUTRITION
Sponges feed on particles such as plankton, bacteria, dinoflagellates and viruses that flow through their bodies together with water. These particles range in size from 50 µm to 1µm or even less. All sponge cells are able to ingest particles by phagocytosis which ensures a more efficient nutrient uptake (Ruppert et al., 2004).
The size of the particle determines the way by which food is filtered, digested and egested:
Particles > 50 µm are phagocytosed by cells of the exopinacoderm. Particles of 5 to 50 µm lodge into an incurrent canal. They are phagocytosed by endopinacocytes or by archeocytes. Particles that are smaller than 5 µm enter choanocyte chambers (Ruppert et al., 2004).
Sponges increase their nutritionaluptake by hosting photosynthetic endosymbionts in their tissue and especially in environments where the amount of appropriate nutrients is low, these symbioses can ensure the survival of the sponge (Pile et al., 2003; Ruppert etal., 2004).
In case of Haliclona cymaeformis the phototrophic alga does not seem to be essential for the sponge’s food supply. Indeed, Haliclona cymaeformis seems to be able to satisfy its needs by grazing on ultraplankton (Pile et al., 2003). The sponge’s nutrient uptake by grazing would actually suffice to provide the alga with enough nitrogen to ensure its growth (Davy et al., 2003). Ceratodictyon spongiosum receives most of its required carbon by photosynthesis and translocates very little photosynthates to the sponge (Pile et al., 2003).
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