1. The three grades of metazoan animals
Animalia
KINGDOM:
Mesozoa
GRADE:
Parazoa
Eumetazoa
PHYLA:
Placozoa
Porifera
Mesozoa
All other animal phyla

2. Phylum Porifera the sponges
1st phyla we will talk about and what we will cover in the lab today is…
the sponges

3. Phylum Porifera Branch Parazoa – “beside + animal”
Sponges are at the cellular level of organization and have no tissues or organs.
Sponges are assemblages of cells embedded in a protein matrix and supported by a skeleton of needle-like structures.
For a long time, taxonomists did not think sponges were animals  branch parazoa
But they are animals! Why an animal?
Mulitcellular and Sessile but have moving cells, sperm, larvae, etc…
Cellular organiztion

4. External Morphology Size: range mm to >2m Color: lots
Shape: encrusting, boring, free-standing, branching, lobed…

5. General Body Plan osculum spongocoel ostia choanocytes water
(plural=oscula)
spongocoel
Despite all this diversity in size, shape and color, most sponges have the same general body plan where
They have holes where water comes in, canals where the water passes thru them, and a hole where the water comes out
ostia
(singular=ostium)
choanocytes
water

6. General Body Plan Choanocytes: “collar cells”
diagnostic of phylum Porifera
consist of a long flagellum surrounded by a “collar” of microvilli
functions:
obtaining food
creating water currents
reproduction

7. General Body Plan osculum spongocoel ostia choanocytes water
(plural=oscula)
spongocoel
Despite all this diversity in size, shape and color, most sponges have the same general body plan where
They have holes where water comes in, canals where the water passes thru them, and a hole where the water comes out
ostia
(singular=ostium)
choanocytes
water

8. 3 Body Types Based on the complexity of the water canals: Asconoid
Syconoid
Leuconoid
Although in other phyla we learn classes, for porifiera we will learn 3 main body types
Increasing size
Increasing Surface Area :Volume

9. Asconoid Body Type osculum spongocoel ostia water
(plural=oscula)
spongocoel
Despite all this diversity in size, shape and color, most sponges have the same general body plan where
They have holes where water comes in, canals where the water passes thru them, and a hole where the water comes out
ostia
(singular=ostium)
water
Choanocytes line the spongocoel (the black shaded area)

10. Syconoid Body Type osculum ostia incurrent canals radial canals
(plural=oscula)
ostia
(singular=ostium)
Water flow
incurrent
canals
radial
canals
spongocoel
choanocytes line the radial canals (the black shaded area)

11. Syconoid Body Type prosopyle: radial canal: apopyle:
opening from incurrent canal to radial canal
Water flow
radial canal:
lined with choanocytes
apopyle:
opening from radial canal to spongocoel

12. Leuconoid Body Type oscula flagellated chambers spongocoel ostia
Water flow
spongocoel
ostia
Choanocytes line the flagellated chambers (the black shaded area)

13. Leuconoid Body Type
prosopyle: opening form incurrent canals to flagellated chambers
ostia
incurrent canal
apopyle: opening form flagellated chambers to spongocoel
Water flow

14. 3 Body Types Based on the complexity of the water canals: Asconoid
Syconoid
Leuconoid
Although in other phyla we learn classes, for porifiera we will learn 3 main body types
Increasing size
Increasing Surface Area :Volume

15. SA = l2 X 6
V = l3

16. The large SA:V of leuconoid sponges
More space for choanocytes
More water flow
Larger size
Water flow

17. Microscopic Morphology
archaeocyte
(amoebocyte)
porocyte
choanocyte
pinacocyte
mesohyl
spicules

18. Skeletal Elements Mesohyl
proteinaceous matrix that contains skeletal material and certain cell types
equivalent to the connective tissue in other organisms
made of collagen
and spongin

19. Skeletal Elements Spicules made of calcium carbonate or silica
often used in taxonomic identification

20. Cell Types Choanocytes diagnostic of phylum Porifera
consist of a long flagellum surrounded by a “collar” of microvilli
functions:
obtaining food
creating water currents
reproduction

21. Cell Types Archaeocytes also called “amoebocytes”
found throughout mesohyl
totipotent  can differentiate into any other type of cell
functions:
digestion through phagocytosis
make spicules
reproduction

22. Cell Types Pinacocytes line the exterior surface of the sponge
functions:
some can regulate water flow by moving (open/close ostia)
outside of sponge
inside of sponge

23. Cell Types Porocytes found in asconoid sponges
form tubes in the body wall where water can pass through
functions:
allow water flow
outside of sponge
inside of sponge

24. Physiology Feeding Digestion Gas exchange
Sessile filter-feeders
Digestion
Intracellular
Gas exchange
Simple diffusion
Excretion (nitrogenous waste removal)
**THE CARNIVOROUS EXCEPTION** Sponges of a particular family (Cladorhizidae) are actually carnivorous! They capture small crustaceans with their velcro-like spicules. Cells then migrate around the helpless prey and digestion takes place extracellularly

25. Physiology Reproduction 1. Asexual fragmentation budding regeneration
gemmules

26. Physiology Gemmules: in freshwater sponges only
resistant mass of archaeocytes that are produced in unfavorable conditions
when the environment is favorable, they will develop into sponges
                                                 

27. Physiology Reproduction 2. Sexual usually monoecious
(a single individual produces both male and female gametes; both sexes are within one individual)
sperm are released into the water and eggs are retained within the sponge
motile larvae are produced
                                                 

28. Some sponge larvae crawl along the bottom, whereas others are free swimming.
Haliclona broods free-swimming parenchymella larvae that are assumed to be sexually produced
These larvae are uniformly ciliated and possess directional swimming while constantly rotating along their longitudinal axis
Larvae are released in the early summer (may-june) and
over the course of several days, a small piece of ripe sponge (~5cm2) can release an average of 30 larvae to a maximum of over 100 larvae
Under laboratory conditions, they swim for approx. 2-4 days prior to settlement and after which they rapidly metamorphose into small-sponges
After release, larvae often aggregate at the water surface, swimming in tight circles around each other...

29. B. Some free-swimming larvae are capable of fusing with others!
   These chimeric larvae continue to swim normally and are capable of successful metamorphosis into a juvenile sponge.
fig A: a larval fusion approx. 20min after initial fusion
fig B: the same larval fusion this time approx. 60 min after intial fusion
These chimeric larvae are approximately double the size of single larvae, and upon metamorphosis, chimeric tissue is noticeably denser and covers a larger area than non-chimeric tissue (pers obs).

30. Larvae eventually settle and metamorphose into adults
Haliclona broods free-swimming parenchymella larvae that are assumed to be sexually produced
These larvae are uniformly ciliated and possess directional swimming while constantly rotating along their longitudinal axis
Larvae are released in the early summer (may-june) and
over the course of several days, a small piece of ripe sponge (~5cm2) can release an average of 30 larvae to a maximum of over 100 larvae
Under laboratory conditions, they swim for approx. 2-4 days prior to settlement and after which they rapidly metamorphose into small-sponges
After release, larvae often aggregate at the water surface, swimming in tight circles around each other...

31. Ecology
most sponges are marine (~5000 species) but there are ~150 freshwater sponge species
Sponges are found at all depths but certain species are restricted to particular depths due to how their spicules are formed
There are few sponge predators because they usually contain distasteful toxins
Some predators (e.g. sea slugs) sequester these sponge toxins which in turn deters their own predators
-Depending on what spicules are made of, they are found at depths where the substance is not soluble. Eg. Calcium carbonate ones are in shallow water, silica ones are deeper
-predators: eg.sea turtles, sea slugs
-usually brightly colored to deter predators
Sea slugs that eat them are also usuall brightly colored advertising their own distastefulness

32. Ecology Symbiosis – Types of symbiotic relationships:
the living together of 2 different species in an intimate relationship
Types of symbiotic relationships:
Mutualism= both partners benefit
Commensalism= 1 partner benefits, 1 partner is unaffected
Parasitism= 1 partner benefits, 1 partner is harmed
There are examples of all 3 of these types of symbiotic relationships occurring in Sponges
-Depending on what spicules are made of, they are found at depths where the substance is not soluble. Eg. Calcium carbonate ones are in shallow water, silica ones are deeper
-predators: eg.sea turtles, sea slugs
-usually brightly colored to deter predators

33. Ecology
Mutualism –
certain ‘endosymbiotic’ bacteria and algae living within the sponge provide additional food for the sponge while the sponge provides a place for the bacteria and algae to grow
-benefit for crab
Benefit for sponge
some crabs will attach a piece of sponge to their body to use as camouflage and to deter predators while the sponge gets to move around

34. Ecology Commensalism –
many different species live within sponges and receive food and shelter benefits but do nothing for the sponge
e.g. 15cm² piece of sponge in California was found to house 100 different species of plants + animals
e.g.Venus’s Flower basket
a pair of shrimp live their entire lives
within 1 sponge
-Depending on what spicules are made of, they are found at depths where the substance is not soluble. Eg. Calcium carbonate ones are in shallow water, silica ones are deeper
-predators: eg.sea turtles, sea slugs
-usually brightly colored to deter predators

35. Ecology
Parasitism –
boring sponges are parasites on certain corals because they bore into the calcium carbonate base of the coral for protection and kill part of the coral in the process
-secrete a substance to dissolve the Caco3 by the archaeocytes nd bore into the coral
-they then excrete the bits of shell through their oscula

36. FSU Research on Sponges: Dr. Janie Wulff
Smithsonian Institution field station at Carrie Bow Cay

37. The sponge communities of reefs and mangrove islands are very different. What factors are responsible for this difference?
1. Abiotic factors: Light, turbidity, nutrients, substrate, physical disturbance…
2. Biotic factors: competition, predation, parasitism…

38. The sponge communities of reefs and mangrove islands are very different. What factors are responsible for this difference?
1. Abiotic factors: Light, turbidity, nutrients, substrate, physical disturbance…
2. Biotic factors: competition, predation, parasitism…
Determining which of these is more important is difficult because reefs and mangroves differ in abiotic and biotic factors.

39. What factors determine the diversity of sponges in a habitat?

40. What factors determine the diversity of sponges in a habitat?
Twin Cays
Pelican Cay
-Species composition: there are 167 species in both habitats combined, but 78 % of the species are found in only one of the two locations.

41. What factors determine the diversity of sponges in a habitat?
Twin Cays
Sponges grow on mangrove roots
Sponge diversity is typical of mangrove stands throughout the Western Atlantic

42. What factors determine the diversity of sponges in a habitat?
Pelican Cay
Sponges grow on mangrove roots
Sponge diversity is typical of shallow coral reefs

43. Why do these two similar habitats have such different sponge communities ?
Transplant experiments: small pieces of sponge from each habitat were attached to mangrove roots in the native and non native habitat
Twin Cay sponges
Pelican Cay sponges

44. Transplant experiments: 1. Caging experiments: the role of predation
Why do these two similar habitats have such different sponge communities ?
Transplant experiments:
1. Caging experiments: the role of predation
Twin Cay sponges transplanted in Pelican Cay
uncaged TC sponge
caged TC sponge

45. Competition Results:

46. Competition Results:
Sponge predators in Pelican Cay:
Gray angelfish
Redband parrotfish
These spongivores are also present on reefs.

47. Transplant experiments: 1. Caging experiments: the role of predation
Why do these two similar habitats have such different sponge communities ?
Transplant experiments:
1. Caging experiments: the role of predation
2. Competitor free space: the role of competition
TC sponge
Pelican Cay sponges transplanted in Twin Cays
uncaged PC sponge
sponge attached to pvc

48. Competition Results:
Sponges in competitor free space have higher survival
Wulff, in press

49. Competition Results:
Sponges in competitor free space tend to grow more
Wulff, in press

50. Competition Results:
Pelican Cay
Twin Cays
There is a positive relationship between growth and survival in Twin Cays, but not in Pelican Cay
Wulff, in press

51. The sponge communities of reefs and mangrove islands are very different. What factors are responsible for this difference?
Dr. Wulff’s research suggests that biotic factors (predation and competition) are important :
Competition plays a more important role in determining sponge diversity in mangrove habitats.
Predation plays a more important role in determining sponge diversity in coral reef habitats.

52. The sponge communities of reefs and mangrove islands are very different. What factors are responsible for this difference?
Dr. Wulff’s research also suggests that there maybe a trade-off between competitive ability and predator defense:
Species found on reefs ?
Defensive ability
Species found in mangroves ?
Competitive ability