Invertebrates: Phylum Porifera – The Sponges

Introduction to Kingdom: Animalia The ocean is where life is thought to have once evolved. And of that life, animals are the most diverse kingdom in appearance Animals are heterotrophic, eukaryotic, and multicellular and lack cell walls. 95% = invertebrates (do not have backbone) 5% = vertebrates (have a backbone)

Invertebrates: Sponges phylum porifera Sponges are best described as aggregations of specialized cells Do not form true tissues Simplest multicellular animals Nearly all are marine All are sessile (permanently attached to substrate)

Phylum Porifera: Sponges

Invertebrates: Sponges Sponges are suspension feeders (filter feeder) As sponges get larger, they need structural support. Most have spicules, transparent siliceous or calcareous supporting structures of different shapes and sizes. ( Mercedes Benz shape …) Many also have tough elastic fibers made of a protein called spongin

Giant Sponges!!!

Anatomy of a Sponge Outer surface is covered with flat cells called pinacocytes and occasional tube-like pore cells (porocytes) through which a microscopic canal allows water to enter. Water is pumped into a larger feeding chamber line with collar cells (choanocytes) Each collar cells has a flagellum the creates currents and traps food particles. Water then exits through a large opening on top of the sponge – osculum. Sponges are sexual and asexual reproducers and some are hermaphrodites.

Anatomy of a Sponge

One of nature’s most efficient filter feeder

Biology of sponges Sponges benefit some marine animals by providing a habitat Some sponges are green because they have photosynthetic organisms in their tissues Many sponges protect themselves from predators by producing toxins Some biologists believe sponges evolved independently from all other animals Some sponges live on the seafloor and some on lake bottoms

Large species of the class Demospongia are harvested for commercial use Their dried spongin skeletons can hold as much as 35 times their weight in liquid Many Greek sponge fishers emigrated to Tarpon Springs, Florida, where their descendants still fish the sponge beds off the Florida coast. Commercial use of sponges

Fishing for sponges

It takes approximately 5 years for a sponge in the wild to reach a marketable size (12.5 cm / 5 in.) and it will retail for about $10.00 Sponges may also prove to be sources of novel medications for fighting disease. A chemical called cytosine arabinoside blocks DNA synthesis in tumors and is used in the treatment of cancer. Sponges also produce antibacterial chemicals that are being studied. Commercial use of sponges

Medicinal Potential