What are the ecological roles of sponges and what are the latest understanding of these roles?

1. What are the ecological roles of sponges and what are the latest understanding of these roles? Group 4: Jessica Mullins, Rory Smart, Ryan Lee, Lauren Stagner, and Cosmo Kunzelmann

2. Symbiosis in Sponges • The encrusting sponge genus Lissodendoryx has extended its range into seagrass meadows by letting itself be surrounded or overgrown by seagrass which is distasteful to the local starfish and therefore protect Lissodendoryx against them; in return the seagrass sponges get higher positions away from the sea-floor sediment. • Sponges with photosynthetic endosymbionts produce up to 3 times more oxygen than they consume, as well as more organic matter than they consume. • Certain hermit crabs place bits of sponge onto their shells. The sponge bits, now given a clean place to grow free from competitors, soon overgrow the shell. This provides the crab with camouflaging and likely chemical protection. • Many are used as homes for all sorts of fish and crustaceans.

3. The effects of sponges on water quality • Marine sponges make up the bulk of deep water communities. • Sponges harbor a range of microbes which are used by the sponges to regulate nitrates in the surrounding water • Sponges create habitats for aerobic microbes (who are responsible for nitrification) and anaerobic microbes (responsible for denitrification, ammonium oxidation) respectively. • these habitats are created by controlling the influx of water/oxygen into the sponge • This is the first proof of ammonium oxidation and denitrification in the same animal host recorded. • Sponges work as nitrogen sinks in the ocean

4. Boring Sponges • Thick, and bright yellow • Can grow up to several square feet • Grows on oyster reefs and other mollusk colonies • Bore holes into oyster shells to find shelter • Weakens shell can no longer offer protection and the host will either die outright or be vulnerable to predators • Impact fisheries by weakening oyster beds • Beneficial to marine environment by recycling calcium carbonate back into the water system (attach to mollusk shell that would have taken years to dissolve) • Bioerosion: wearing away of shell or rock by animals such as sponges

5. Freshwater Sponge Ecology • Around 150 known species • Do not tolerate pollution • Serve as food for small aquatic invertebrates like Caddis Flies and Mayflies • The highest growth rates are during the spring and the fall with a dormant stage during the winter.

6. Prey- What do Sponges eat? • Most sponges are detritivores -- they eat organic debris particles and microscopic life forms that they filter out of ocean water. • However, a few species such as the harp sponge (Chondrocladia lyra) have been found to be carnivorous. Harp sponges are known to have vanes radiating out from a center. Each vane has vertical branches lined with hooks. The hooks on the sponge's arms catch tiny shrimp when ocean currents push the crustaceans the sponge's way. Once a sponge has caught an animal, the sponge envelops it in a membrane and begins to slowly digest it.

7. Predation- Who eats Porifera? • Hawksbill turtles do! • Unlike other turtles, sponges are a main part of the Hawksbill turtles diet • Important because: Spongivory by Hawksbill turtles affects space competition and may influence succession and increase diversity of reef communities • Some fish and sea slugs • Sponge flies are specialized sponge predators that lay their eggs in leaves overhanging the water, and when their larvae hatch, they fall into the water and use the sponges for both food, and shelter. • 2 Attributes that sponges have for defense: • Skeletal- Spicules for physical defense • Secondary metabolites that provide chemical defenses

8. References Boring Sponges. Retrieved from http://www.chesapeakebay.net/fieldguide/critter/boring_sponge H., Mark. Retrieved from http://www.dailykos.com/story/2007/05/11/333705/-Marine-Life-Series-Boring-Sponges Hoffmann, F., Radax, R., Woebken, D., Holtappels, M., Lavik, G., Rapp, H., & ... Kuypers, M. (n.d). Complex nitrogen cycling in the sponge Geodia barretti. Environmental Microbiology, 11(9), 2228-2243. Meylan, A. (1988). Spongivory in hawksbill turtles: a diet of glass. Science(Washington), 239(4838), 393-395.