2. Sponges
● invertebrates
● radial symmetry or are asymmetrical
● multicellular but no cell specialization
● living in fresh and marine waters
3. Internal
● spongocoel: central cavity
○ covered with choanocytes
■ flagellated cell with a collar; generate water
currents and collars trap food particles
● osculum: larger openings
● spicule:
○ a needle-like structure or part, such as on of the
mineral structures, supporting the soft tissue of
certain invertebrates
4.
5. Nervous System
● sponges do not have a nervous system; no
brain, no nerve cells
● nerve net
○ a diffuse network of neurons that conducts impulses
in all directions from a point of stimulus
● touch or pressure to the outside of a sponge
will cause a local contraction of its body.
6. Respiration and Circulation
● through its pores with canals that move the
water to all throughout the sponge; then the
oxygen from the water is used.
7. How Sponges Eat (Digestion)
● Sponges are characterized by the possession of a
feeding system unique among animals.
● Poriferans don't have mouths; instead, they have tiny
pores in their outer walls through which water is drawn.
● Cells in the sponge walls filter bacteria from the water
as the water is pumped through the body and out other
larger openings.
● The flow of water through the sponge is unidirectional,
driven by the beating of flagella which line the surface of
chambers connected by a series of canals.
● Heterotrophic
● Suspension feeders
8. ● In all cases, poriferans have a canal system, through which they pump
water.
● Water enters through pores called ostia, flows through canals to a chamber
called a spongocoel, and finally exits through large openings called oscula.
9. Excretion
● A sponge has carbon dioxide and other
wastes removed as the water moves in and
out through the pores.
10.
11. Reproduction
● reproduces by budding and also sexually
● hermaphorodites: individual functions as both male and
female in sexual reproduction by
● producing sperm and eggs.
● dioecious: having the male and female reproductive
organs in seperate individuals.
● eggs: archeocytes (totipotent cells that have the ability
to divide and produce al the differentiated
cells in an organism) or
choanocytes
● sperm: choanocytes
13. Hexactinellida
● glass sponges
● viewed as an early branch within Porifera
● much of their tissues are syncitia, extensive
regions of cytoplasm
● possess a unique system for rapidly
conducting electrical impulses across their
bodies, allowing them to react quickly to
external stimuli
14. Demospongia
● most diverse sponge group
● tend to be large
● brightly colored
● reproduce both sexually and asexually
● harvested by divers, then bleached and
marketed to be sold as bath sponges
15. Calcarea
● mainly live in the tropics
● mainly found in shallow waters
● small and dull in color
16. Carnivoruos Sponges
● from the family Cladorhizidae
● they capture small crustaceans with their spicules
● spicule:
○ a needle-like structure or part, such as on of the
mineral structures supporting the soft tissue of
certain invertebrates, especially sponges.
● cells migrate to the organism
● digestion takes place extracellularly
