Intro to Animals

General Characteristics Multicellular eukaryotic heterotrophs Trends in animal evolution: Asymmetrical  Radial  Bilateral Cephalization : sense organs/nerves start to centralize in anterior region

Symmetry

Symmetry

Anatomical Directions

To Do’s Dictionary Asymmetry, radial symmetry, bilateral symmetry, cephalization, [the 6 body directions]

What did you notice?

Porifera

Porifera General Characters “pore-bearers” Sessile adults Asymmetrical (sometimes radial) No specialized gut/organs/systems DOES have specialized cells

Structure Osculum; spicules; spongin; spongocoel; amoebocyte; colar cells; water flow

Sponge Structure Osculum; spicules; sponging; spongocoel; amoebocyte; colar cells

Skeleton (don’t write) Sponge body is made of interwoven spicules and/or spongin [proteins] Spicules: hard, pointy fibres Spongin: soft, flexible fibres Include on drawing

Don’t write! Water flows through the pores into the central cavity and out of the osculum. Collar cells draw out the food from the water as it flows through the pores. Show show show show

Spicule Skeleton

Structure Flagellated cells beat & twirl  create water current to & through sponge Important for many body functions Write again!

Body Functions Due to water current through sponge & spongocoel Feeding: filter feeders [suck in water with algae /microscopic particles; keep food, spit back out water] Resp/Circ/Excretion: wastes dissolve into water current and swept out; new water brings new oxygen

Life History

Life History Asexual: budding or gemmules [Groups of archaeocytes with spicule covering; can survive freezing and drought; in favorable conditions grows into new sponge]

To Do’s Q’s [next slide] Life Table – Porifera(?) Dictionary Asymmetry, radial symmetry, bilateral symmetry, cephalization, [the 6 body directions] Filter feeding, sessile, motile

To Do’s Q’s [next slide] Life Table – Porifera(?) Dictionary Filter feeding, sessile, motile

Questions How does a sponge move water through its body? Why is this water movement so important for the sponge? Describe how a sponge obtains & digests food When faced with a difficult environment, sponges produce gemmules. How does this help the sponge? How might the extinction of a sponge species affect other organisms in the area?