Porifera (PDF)

Chondrocladia lyra (Lee, Reiswig, Austin & Kundsten, 2012)  Porifera Nature.com Dr Craig Robertson [email protected] IMarEst 2020 Lecture 1 Lecture 2 Lecture 3  Outline Introduction Key characteristics...

Chondrocladia lyra (Lee, Reiswig, Austin & Kundsten, 2012)  Porifera Nature.com Dr Craig Robertson [email protected] IMarEst 2020 Lecture 1 Lecture 2 Lecture 3  Outline Introduction Key characteristics Body structure Morphological diversity Feeding Reproduction Classes and distribution © sharon-taxonomy2010-  Introduction Isolated phylum Multicellular, sessile organisms 5,500 - 9,000 described species Ancient lineage (appeared 540 mya) Restricted to benthic marine environments Occur at all depths © carinbondar.com © www.studyblue.com  Classification Kingdom: Metazoa (multicellular animals) h a r p Phylum o Porifera rom le c Class os om H Calcarea Hexactinellida Demospongiae  Key characteristics Metazoa Without true tissues or organs Asymmetrical Totipotent cells - Amoebocytes Body formed of monolayer of cells surrounding a secreted matrix  Body structure Outer surface (pinacoderm) comprised of pinacocytes Can be simple, external sheet with ostia NB: not present in Hexactinellida (thin dermal layer) Inner surface (choanoderm) comprised of choanocytes Simple and continuous or folded and subdivided Separated by mesohyl (made of mesenchyme) Varies in thickness Several vital roles Body structure http://www.ucmp.berkeley.edu/porifera/pororg.html  Aquiferous system Brings water through the sponge Water pulled in through ostia Driven across choanoderm by beating of choanocyte flagella Choanocytes pump large volumes of water through the body at low pressures Establishes a water current 24,000 L day-1 kg-1 (Taylor et al. 2007)  Water flows close to cells responsible for food gathering and gas exchange Excretory and digestive wastes and reproductive products expelled via osculum  Morphological diversity Asconoid Simple and continuous choanoderm (many newly settled calcareous sponges ≤ 10cm high) Syconoid Simple folding of pinacoderm and choanoderm (some calcareous species) Leuconoid Folding and subdivision of choanoderm (most calcareous, all demispongiae) © eplantscience.com  Feeding Filter feeders Use aquiferous system in feeding Size-selective particle feeders Arrangement of aquiferous © mesa.edu.au system creates series of sieves of decreasing mesh size; 5- 50µm, down to 2-5µm Intracellular digestion Amoebocytes /Archaeocytes transport nutrients throughout the mesenchyme  Reproduction Sexual Hermaphrodites Produce eggs and sperm at different times Produced (usually) by choanocytes and released via aquiferous system Oviparous and viviparous species Larval ecology typically split by habitat (littoral/ subtidal)  Reproduction Asexual Fragmentatio Asexual Larvae n - Gemmules Budding © quizlet.com © quizlet.com  Class Calcarea ~400 sp © marlin.ac.uk Calcareous sponges (shallow) Rayed spicules (1, 3, 4 actines) composed of calcium carbonate Two subclasses: Subclass Calcinea Subclass Calcaronea © marlin.ac.uk © horta.uac.pt © marlin.ac.uk Clathrina coriacea Sycon ciliatum Leucosolenia botryoides  Class Hexactinellida ~400 sp Glass sponges (deep) Spicules are six-rayed (hexactinal) and siliceous © bbc.co.uk Two subclasses: Subclass Amphidiscophora Subclass Hexasterophora © University of Victoria © Ben Wigham  Class Demospongiae >8000 sp Demosponges (76% of living species) Spicules are siliceous but not hexactinal Three subclasses: Subclass Homoscleromorpha Subclass Keratosa Subclass Verongimorpha Halichondria panicea Bread-Crumb Sponge © marlin.ac.u k Tethya aurantium © marlin.ac.uk Golf Ball Sponge Axinella infundibuliformis Prawn Cracker Sponge Distribution  Distribution Distributional patterns among the three classes Calcareous and coralline demosponges Abundant in shallow water (less than 200 m), need firm substrate Hexactinellids Largely restricted to depths below 200 m (except in extremely cold environments) Demosponges Present at all depths  Summary Introduction Key characteristics Body structure Aquiferous system Morphological diversity Feeding Reproduction Sexual and asexual © sharon-taxonomy2010-p2.wikispaces.com Classes and distribution Calcarea, Hexactinellida Demospongiae and Homoscleromorpha  Resources Barnes, R.S.K., Calow, P., Olive, P.J.W., Golding, D.W. & Spicer, J.I. (2001). The Invertebrates: a synthesis. Oxford, Blackwell Science. Brusca, R.C. & Brusca, G.J. (2003). Invertebrates. Sunderland, MA, Sinauer Associates, Inc. Chapter 6 Crothers, J. (1997). A Key to the Major Groups of British Marine Invertebrates. Shrewsbury, Field Studies Council. Fish, J.D. & Fish, S. (1996). A Student’s Guide to the Seashore. Cambridge, Cambridge University Press. Hayward, P., Nelson-Smith, T. & Shields, C. (1996). Collins Pocket Guide Seashore of Britain and Europe. London, HarperCollins Publishers. Lee, W. L., Reiswig, H. M., Austin, W. C., & Lundsten, L. (2012). An extraordinary new carnivorous sponge, Chondrocladia lyra, in the new subgenus Symmetrocladia (Demospongiae, Cladorhizidae), from off of northern California, USA. Invertebrate Biology, 131(4), 259-284. Taylor, M. W., Radax, R., Steger, D., & Wagner, M. (2007). Sponge-associated microorganisms: evolution, ecology, and biotechnological potential. Microbiology and molecular biology reviews, 71(2), 295-347.