Phylum Porifera (sponges) Classification of sponges Class Calcarea • Share cellular organization • Class Demospongiae (cellular vs. syncitial) Diversity Share spicules’ chemistry • Class Hexactinellida (carbonate vs. silicon dioxide) Diversity of sponges Diversity of sponges • Class Calcarea • Class Calcarea • “obscure and taxonomically difficult” • “beautiful and fragrant” • Class Demospongiae • small, colorless • ~500 described species Class Hexactinellida = Glass Sponges likely a monophyletic group • • • Entirely marine and usually deep water • Siliceous spicules of triaxonic symmetry; • Class Demospongiae usually fuse together • Living tissues are mainly syncytial • Class Hexactinellida • ~500 described species Diversity of sponges • Class Calcarea • Class Demospongiae • Marine and freshwater; all depths • All shapes and colors • Siliceous spicules, collagen fibers, both or none • ~6000 described species • Class Hexactinellida Euplectella aspergillum = Venus’s flower basket Haliclona manglaris Tedania ignis Chalinula molitba C M O A R Neofibularia nolitangere Verongula rígida Ircinia strobilina N A G L R Oceanapia nodosa Mycale Amphimedon erina O microsigmatosa Aplysina archeri Aplysina fistularis Geodia neptuni V R E E S E F Agelas conifera Ptilocaulis walpersi Cliona delitrix Photos by MC Díaz Photos by S. Zea Hyalonema Aphrocallistes vastus Staurocalyptus dowlingi Tedania ignis Xestospongia muta Clathria shoenus S D E E A E G Leys P R Spheciospongia vesparia A S S S Platylistrum E Rosella A Amphimedon viridis, Aplysina fulva, Chondrilla nucula, Clathria Pleurochorium eschoenus, Cliona varians, Desmapsamma anchorata, Dysidea etheria annandale Photos by S. Zea and MC Díaz Hexactinellid Sponges 200 - 8000 m Lubromirskia baicalensis Volkmer-Ribeiro F R E S Corvoheteromeyenia heterosclera H Ephydatia muelleri Spongilla lacustris Eichhornia crassipes W A T E Volkmer-Ribeiro R Radiospongilla amazoniensis What is a sponge? A porous animal (Porifera = ‘pore bearing’) From NBE What is a sponge? What is a sponge? • Metazoans with a cellular grade of organization, no organs, no nerves, no true tissues • Sessile; movement limited to concerted crawling by cells (re-modeling) • Adults asymmetrical; larvae radially • A lucrative industry. Traders distinguish 400 commercial symmetrical varieties. In fact, only 7 (endangered) species from Mediterranean and 9 species from Caribbean • Body a system of water canals • Fortunately, bath sponges are only a few species out of ~ 15,000 (We’ll see why shortly) .