1. Chapter 8
Lower Invertebrates

2. Bellringer PHONES OFF and in Caddy Cnidarian Vocabulary Page 195-205
Complete chapter 7 review

3. Bellringer
PHONES OFF and in Caddy
Cnidarian Vocabulary Page

4. What Are Animals? Animals: are multicellular
distinguishes them from bacteria and most protists
have eukaryotic cells without cell walls
distinguishes them from bacteria, fungi, algae and plants
cannot produce their own food, depend on other organisms for nutrients
can actively move at least at some point during their life cycle
invertebrates = animals that lack a vertebral column (backbone
vertebrates – animals with a vertebral column
majority of animals in sea are invertebrates

5. Taxonomy Kingdom – Animalia Subkingdom – Parazoa (lacks tissues)
Phylum – Porifera (pores)

6. Phylum Porifera: Sponges
The first animals we will talk about are sponges
Sponges are the simplest of multicellular animals
They have no tissues, organs or nervous system
cells show little differentiation and specialization.
They are asymmetric
Sessile
Variety of growth forms and colors

7. Bellringer Phones OFF and in caddy 15 min.-Chapter 8 sponges Vocab
If you have completed this move onto the next section cnidarians

8. Sponge Anatomy
Sponges are filter feeders, and constantly circulate water through their bodies
They have many small incurrent holes called ostia, and one or few excurrent holes called the osculum
The cavity inside the sponge is called the spongocoel

9. Sponge Anatomy
Sponges lack specialized tissues, instead they have certain cell types that are specialized to perform a function
Choanocytes (collar cells) line the spongocoel and use a flagellum to move water through.
they also trap suspended food particles.
Archaeocytes are amoebalike cells that move throughout the body to transport food and aid in repair and regeneration.
can assume any of the other cell forms
transport materials
important role in repair and regeneration

11. Sponge Anatomy
Sponges lack specialized tissues, instead they have certain cell types that are specialized to perform a function
Sponges have spicules; produced by pinacocyts, these are skeletal elements made of calcium carbonate, silica or spongin that provide structural support.
Spongin is a protein that forms a flexible fiber found in sponges of the class Desmospongia, the sponges that are harvested commercially.
Helps also with protection – will keep other animals from eating the sponges

12. Sponge Skeletons
Silica Spicules
Limestone Spicules
SPONGIN

13. Sponge Skeletons
VENUS FLOWER BASKET
SPICULES

14. Water exits through osculum Spicule Archaeocyte Pinacocyte Water
enters
through
small
pores
(ostia)
Spongocoel
(choanocyte)
Collar
cell
Spongocoel
Archaeocyte
Spicule
Pinacocyte
Pore cells
Ostium
Flagellum
Collar
Food particles
Fig. 8-1, p. 193

15. Size and Body Form
The size of a sponge is limited by its ability to circulate water through its body, which in turn is limited by its body form.
The simplest of sponges are small and tubular.
Increasing folding of the body wall in more complex sponges allows for an increased surface area for choanocytes and allows those sponges to grow to a bigger size (Figure 6.2).

16. Figure 6. 2. Main growth forms in sponges. More complex folding (e. g
Figure 6.2. Main growth forms in sponges. More complex folding (e.g. leuconoid) allows increased surface area for collar cells and a bigger size.

18. Branching Tube Sponge

19. Stove Pipe Sponge

20. Vase Sponges

21. Barrel Sponges

22. Ball Sponges

23. Rope Sponges

27. Encrusting sponges

28. Nutrition and Digestion
Sponges are suspension feeders (or filter feeders), and create a current of water through their body by the beating of the flagella in the choanocytes.
In this way they capture small particles in the water including bacteria, plankton and detritus.
Food particles get trapped in the collar cells (choanocytes) and are transported through the sponge by the archaeocytes
which also function in food storage.
Undigested materials and waste products exit the sponge through the osculum.

29. Reproduction
Sponges can reproduce asexually by budding, where a group of cells on the outer surface of the sponge develop and grow into a new sponge.
When these are developed the new sponges drop off and settle nearby.
Another method of asexual reproduction is fragmentation, where pieces broken off by waves and storms develop into new individuals.

30. Reproduction Sponges also reproduce sexually.
Most species are hermaphrodites, and produce both male and female gametes, although not usually at the same time.
Sperm is released in the water column and captured by another sponge.
The sperm is engulfed by a choanocyte and transported to an egg.
The fertilized eggs are released in the water column, where the larvae develop until they are ready to settle on the benthos (Figure 6.3).

31. Figure 6.3. Reproduction in sponges.

32. Ecological Role
Sponges are important inhabitants of shallow water ecosystems and compete for space with animals like corals and bryozoans.
They produce chemicals (toxins) to kill or inhibit their competitors.
Other sponges create their own habitat, such as boring sponges that burrow into coral, thereby playing an important role in calcium recycling.

33. Ecological Role
The spicules and toxins of sponges deter most predators, though hawksbill sea turtles and angelfish have evolved adaptation to withstand them.
Sponges form symbiotic relationships with a variety of other organisms.
Many bacteria and some dinoflagellates live within their tissues, and the spongocoel offers shelter for a variety of organisms.

34. Ecological Role Symbiotic relationships
sponges are mutualistic or commensalistic hosts to many organisms
e.g. symbiotic cyanobacteria
many organisms (shrimp, fish) live within the canals or spongocoel, for protection and to take advantage of water flow

35. Figure 8-4 (a) ECOLOGICAL ROLE OF SPONGES.

36. Ecological Role
Chemicals have been isolated from Caribbean sponges that block DNA synthesis in tumors and there is the prospect of utilizing them in cancer treatment.
The antibacterial properties of sponges are also being studied.

37. Biomedical Use Anti-cancer Antibacterial
Discodermalide
Halaven
Antibacterial

38. Assignment
Sponge Worksheet