Hamilton - Honors Biology Chapter 27 Sponges

porifera

means "pore bearing"; sponges have many pores to draw in water

sponges

simplest animals with no body symmetry, tissues, or organs

sessile

sponges do not move as adults; they are fixed in one place

marine sponges

majority of sponge species (~7000); brightly colored

freshwater sponges

fewer species (~150); usually small and dull green

choanocytes

collar cells that help with feeding by moving water and capturing food

archaeocytes

cells that assist with digestion and can become other cell types

osculum

large opening at the top of the sponge where water exists

filter feeders

sponges filiter tiny food particles from water

respiration

gas exchange by diffusion through water

circulation

movement of nutrients and gasses by water flow

excretion

wastes removed through water flow and diffusion

hermaphrodite

an organism with both male and female reproductive organs

sexual reproduction (sponges)

fertilization produces larvae that swim to settle elsewhere

asexual reproduction (sponges)

occurs by budding or forming gemmules

budding

a new sponge forms from a piece that breaks off

gemmules

clusters of cells that survive harsh conditions and can grow into a new sponge

ecology of sponges

sponges provide habitat and form mutualistic relationships with algae or bacteria

commensalism

relationship where one organisms benefits, and the other is not harmed

mutualism

both organisms benefit, such as sponges and photosynthetic algae