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06 BENTHOS. I. Sponges (Phylum Porifera) A. Evolutionary history 1. Fossil sponges are some of the oldest known multi-celled animals . Fossil Sponge Showing a Honey-combed Pore Pattern. Fort Scott Limestone in Bourbon County, Kansas. A. Evolutionary history (continued)

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slide2

I. Sponges (Phylum Porifera)

  • A. Evolutionary history
    • 1. Fossil sponges are some of the oldest known multi-celled animals
slide3

Fossil Sponge Showing a Honey-combed Pore Pattern

Fort Scott Limestone in Bourbon County, Kansas.

slide4

A. Evolutionary history (continued)

2. In phylogenic studies, sponges have been treated as a sister group to the other animal (= Metazoa) taxa.

slide6

Evolutionary history

  • 3. Recent genetic evidence, however, suggests that the ctenophores may have separated from the other animals before the sponges
slide7

Major events of loss and gain in the evolution of early animal tissue complexity are suggested by the analysis of the first representative genome from the ctenophore phylum

http://www.sciencemag.org/content/342/6164/1327/F1.large.jpg

slide8

I. Sponges (continued)

  • B. Body parts
    • Epithelial cells only (no muscle, connective, nor nervous tissue)
    • Structural protein SPONGIN
  • (1) Coarse collagen fibers
  • (2) Responsible for resilient and absorbent properties of sponge skeleton
slide9

Spongin Fibers

http://media.photobucket.com/user/Zoology1/media/kingdom%20Anamalia/Porifera/Spongefibers2.jpg.html?filters[term]=spongin&filters[primary]=images&filters[secondary]=videos&sort=1&o=0

slide10

B. Body Parts of Sponges (continued)

3. SPICULES

a. Deposits of…

(1) Calcium carbonate

(2) Silica

b. Function to…

(1) …provide structural strength especially in narrow passageways

(2) …inhibit predation

slide12

Spicules from modern sponge

Magnification = 100X

http://media.photobucket.com/user/paulfuentebella/media/Lab%2012/IMAG0164.jpg.html?filters[term]=grantia%20spicules&filters[primary]=images&filters[secondary]=videos&sort=1&o=0

slide13

Spicules from a Fossil Sponge Stained Orange by Iron Oxide

Lower Ordovician, Idaho

http://www.fallsoftheohio.org/Fossil_Sponges.html

slide14

I. Sponges (continued)

C. Rely upon currents to filter-feed

slide16

C. Filter-feeding currents (continued)

1. Water flow

a. Enters through external pores into small passageways known as CHOANOCYTE CHAMBERS

(1) Lined by cells called CHOANOCYTES

(2) Food particles are captured

b. Processed water enters a CENTRAL CAVITY

c. Waste water leaves via openings called OSCULA [= little mouth; osculum = sing.]

slide17

Central Cavity

Central Cavity

Arrows show locations of oscula

slide19

C. Filter-feeding currents (continued)

2. Control of feeding currents

a. Some sponges can pass their own weight in water every 5 seconds

slide20

Cheap Thoughts

By

Jack O’Brien

How does an organism with no muscles “pump” water through its body?

slide21

2. Control of feeding currents (continued)

b. BERNOULLI'S PRINCIPLE:

(1) A decrease in the X-sectional area of a pipe causes an increase in the velocity of a liquid flowing through that pipe (river moves slowly in wide portions of a canyon and rapidly in a narrows)

(2) The volume of a fluid passing by any point remains the same, so a decrease in the X-sectional area at a point results in an increase in flow

slide22

The relationship between the area of a tube and the velocity of a non-compressible fluid passing through that tube. (The lengths of the arrows labelled v represent relative velocities of the fluid.)

http://titans.s716.ips.k12.in.us/~blachlym/pol/ch-09/5/5.htm

slide24

b, BERNOULLI'S PRINCIPLE (continued)

(3) Since the X-sectional areas of all the choanocyte chambers is greater than the area of the osculum…

(a) …the speed of the water current leaving the sponge at the osculum is greater than the speed of the water currents entering pores and the choanocyte chambers

(b) …waste water is carried away from sponge

slide25

More Cheap Thoughts

By

Jack O’Brien

Why don’t algae, barnacles and other encrusting or fouling agents grow on sponges?

slide26

Biofouling

http://www.tvja.org/science/fouling_community_study.htm

slide27

Sponges apparently use

“chemical warfare”

Science 2008, 320: 1030

slide29

Currently there are numerous pharmaceutical companies sponsoring research on chemicals produced by sponges and their symbionts looking for medicinal properties.

This includes Johnson & Johnson original support of the Harbor Branch Oceanographic Institute in Ft. Meyers, FL now affiliated with Florida Atlantic University

slide30

The deep-water submersible Johnson-Sea Link

http://en.wikipedia.org/wiki/File:Johnson_Sealink.png

slide32

Florida Keys

Photo: J. O’Brien, 2011

slide33

Poriferans

Photo: J. O’Brien, 2011

slide34

Large Barrel Sponge

Photo: J. O’Brien, 2011

slide35

II. Mollusks

      • A. Adults lack obvious segmentation
      • B. Specialized structures
        • 1. RADULA
    • a. Rasping tongue-like structure
    • b. Can bore holes in prey or scrape algae from rocks
    • c Possesses a hhardness value of 6 on the Mohs scale
  • (1) Diamond hardness is 10
  • (2) Harder than poor grades of steel
slide36

EM of

Radula

slide37

Specialized structures (continued)

  • 2. Muscular FOOT
    • a. Movement
    • b. Attachment (limpets & abalone)
    • 3. Calcareous SHELL
    • 4. MANTLE
    • a. Thin layer of tissue under shell
    • b. Lays down shell
    • c. Respiratory organ
slide40

Specialized structures (continued)

  • 5. MANTLE CAVITY
    • a. Space between mantle & body organs
    • b. Location of GILLS
    • c. Inhalant and exhalant feeding currents
    • move through it
slide41

II. Mollusks (continued)

C. Most marine mollusks have a TROCHOPHORE larva that develops into a VELIGER

slide42

Castro & Huber

2003, p. 332

TROCHOPHORE larva

Found in Annelids and Mollusks

slide43

D. Gastropoda

        • 1. Most diversified molluscan class (35,000 species)
        • 2. OPERCULUM
          • a. On coiled shelled gastropods
          • b. Hard plate that covers aperture when foot withdrawn
          • c. Functions
          • (1) Protection
          • (2) Prevents desiccation
slide44

Operculum of a Whelk

http://barnegatshellfish.org/images/whelk/operculum_whelk_bb_01_l.PNG

slide45

D. Gastropoda (continued)

  • 3. Neogastropods
        • a. Characteristics
          • (1) Extendible BUCCAL TUBE or PROBOSCIS (snout) with mouth at end
          • (2) Portion of mantle forms a SIPHON
          • (3) Shell has a SIPHONAL CANAL
slide46

Neogastropods (continued)

  • Examples
  • (1) Whelks common in seagrass habitats
slide47

Siphonal Canal

Siphon

Buscyon, Lightening whelk feeding on a bivalve

Lippson & Lippson, 1984, Life in the Chesapeake,p. 53

slide48

Whelk egg string

Photo: J. O’Brien 2013

Common whelklaying eggs

Picture: Ron Offermans http://molluscs.at/gastropoda/index.html?/gastropoda/sea/common_whelk.html

slide49

Coral Reef Gastropods

Photo: J. O’Brien, 2011

slide50

Conchs in a Boat

Photo: J. O’Brien, 2011

slide51

Conchs on a Shelf

Photo: J. O’Brien, 2011

slide52

Conchs in Space

Photo: J. O’Brien, 2011

slide53

Examples of neogastropods (continued)

  • Cone Shells
  • (a) Predators on tropical reefs
  • (b) Teeth of radula are harpoon-like
  • (c) Contain venom
  • (d) Stabbed into prey by proboscis
slide55

E. Bivalves

1. Structures

a. Shell formed of two valves

b. LIGAMENT acts to spring open valves

c. Large powerful ADDUCTOR MUSCLES close valves

(good tasting)

slide56

Clam and Mussel

Painting by Georgia O’Keefe, 1926

slide58

Bivalves (continued)

  • Filter-feeders
  • a. Gills covered with mucus
  • b. Trap suspended particles (= plankton)
  • c. Cilia carry food to mouth
  • d. LABIAL PALPS
          • (1) Reject unsuitable food
          • (2) Form PSEUDOFECES
slide59

Bivalves (continued)

  • Life-styles
  • a. Most bury in unstable substrates
  • b. Dig by contracting valves and moving foot
  • c. Siphon extends up into water column
slide61

Bivalves (continued)

  • 4. Mussels
  • a. Attach to firm substrates with BYSSUS THREADS
  • b. Mytilus edulis
  • (1) Edible mussel
  • (2) Defend themselves by pinning predatory snails with byssus threads
slide62

Littorina, Marsh Periwinkle

Geukensia Ribbed Mussel

(Bivalve)

Lippson & Lippson, 1984, Life in the Chesapeake,p. 162

slide63

Bivalves (continued)

  • 4. Oysters
  • a. Attach with cement
  • b. Mantle secretes cement around attached valve
  • c. Smaller valve remains free
slide64

Oyster Drill

Oyster, Crassostrea, and Associated Mollusks

Lippson & Lippson, 1984, Life in the Chesapeake,p. 123

slide67

Bivalves (continued)

  • 5. Shipworms
  • a. Bivalves that burrow into submerged wood
  • b. Repeated movement of rough valves erodes cavity
  • c. Destroy wharves
slide68

Inhalent & exhalent siphons

Shell

Shipworm removed from tunnel

http://web.forestry.ubc.ca/fetch21/FRST308/lab8/bankia_setacea/bankia%20wormA1_1.JPG

slide69

Wood damaged by shipworms

http://web.forestry.ubc.ca/fetch21/FRST308/lab8/bankia_setacea/Bankia%20in%20galB1_1.JPG

slide70

Bivalves (continued)

  • 6. Tridacna
  • a. “Man-eating” clam
  • b. Harbor colorful zooxanthellae
  • (= symbiotic dinoflagellates)
  • c. Biggest bivalve on tropical reefs