Introduction to Animal Diversity

The Fundamental Problems of Life:

Sponges - Phlyum Porifera

In addition to your text, please read the following:

http://web.archive.org/web/20020804011531/www.animalnetwork.com/fish2/aqfm/1998/jan/wb/default.asp

and

http://web.archive.org/web/20020804005350/www.animalnetwork.com/fish2/aqfm/1998/feb/wb/default.asp

Also, if you are in my Bio 351 class (Invertebrate Biology), see the additional diagrams and photos here:

Additional Sponge Diagrams and Photos

1. Sponges are sessile animals with simple body structure

• simplest structure of all animals
• exclusively aquatic
• mostly marine (saltwater) - ABUNDANT and diverse
• some species in freshwater (unpolluted)

2. Best described as a colony of protist-like cells

• cells not tightly bound together
• no tissues
• no organs
• cells are totipotent

3. Major cell types and structural features:

Cell types

• epidermal cells - form outer covering
• amoeboid cells - wander about, make spicules and skeleton, capture food
• collar cells (choanocytes) - create water currents, capture food
• pore cells - surround incurrent pores
• 
• 

Structural features

• incurrent pores - ostia (sing. ostium)
• excurrent openings -oscula (sing. osculum) (tree sponge photo)
• spongocoel
• skeletal elements -protein and spicules (see diagrams in web article)

Skeleton types

• protein fibers
• calcium carbonate spicules
• siliceous spicules (glass)

Some sponges have only one of the above skeletal components, most have 2 or 3 types (which sorts of sponges are best suited for use as bath sponges?)

4. How sponges function:

• collar cells create water currents
• water drawn in through ostia
• water exits via oscula
• small food particles trapped (mostly bacteria)
• water currents perpendicular to oscula aid flow through sponge

• symbiotic algae are common in sponges (e.g. cyanobacteria in greyish-green chicken-liver sponges)

5. Variety in form (see diagrams in web article)

• asconoid
• 
• syconoid
• 
• 
• leuconoid (most common)
• 

6. Cool things sponges can do:

• many can move to new locations by dissassembly-reassembly (see: chicken liver sponges climbing up turtle grass)
• most sponges canbe disaggregated and cells can reaggregate into new sponge

7. Ecological considerations

• sponges are home to many animals, including brittlestars, polychete worms, snapping shrimp, anemones, and many others:
  • For snapping shrimp information:
    • picture of snapping shrimp and further information
    • snapping shrimp sounds
    • info on sociality infsnapping shrimp: article
  • Photo of zooanthid anemones that live on sponges (these particular anemones live no-where else!)
• sponges are food for various nudbranchs, sea stars, and fish
  • For photos of attractive marine angelfish that eat sponges:
    • http://www.elasmodiver.com/Fish%20Pictures/Emperor_Angelfish_001.jpg
    • http://www.flmnh.ufl.edu/fish/Gallery/Descript/AngelQueen/AngelQueen.htm
    • Beautiful video of French angelfish and grey angelfish grazing on sponges in the Caribbean! https://www.youtube.com/watch?v=lgPuNMJdgrk
      

    (And here is another BEAUTIFUL video showing how abundant and how LARGE sponges can be! https://www.youtube.com/watch?v=8WaWVuGE-LM )

• defenses against predators: toxins and bright colors (warning coloration)

8. Note: Some things that superficially look like sponges are not. This photo was labeled as a sponge in a respected biology textbook, but in fact it is a colonial tunicate, not sponge...Oops!!! Tunicates are VERY different animals!

(click for closeup, or go to p. 655 of Biological Science, by Gould and Keeton)