Porifera Flashcards
What are Porifera
Multicellular sessile sponges restricted to benthic environments at all depths
What are the key characteristics of Porifera
Without tissues or organs
Asymmetrical with lots of totipotent cells
Body formed of monolyer of cells surrounding a secreted matrix
They have choanocytes driving aquiferous systems
How is water brought through the sponge
Water is pulled in through the Ostia which is driven acros choanoderm by the beating of choanocyte flagella
Choanocytes pump large volumes of water through the body at low pressure
As water flows through the sponge gas exchange takes place and detritus is consumed by the cells
Waste is expelled through the osculum
What is the cell body structure of the outer surface of poreifia
Outer surface (pinacoderm): pinacocytes
Is a simple external sheet with Ostia which is not present in hexactinellida
What is the cell body structure of the inner surface of Porifera
Inner surface (choanoderm) : choanocytes
Simple and continuous or folded and subdivided separated by mesohyl
What are spicules
They provide structural support and deter predators they can be calcareous, silicrous or made of protein fibres such as collagen
They have a range of symmetry important for taxonomic ID
How do poreifia feed
Usually filter feeders using aquiferous systems
They are size selective particle feeders
Where aquiferous systems creates a series of seieves of decreasing mesh size
Intracellular digestion
Mesohyl transports nutrients through the body
What is a asconoid sponge
Syconoid sponge
Leuconoid sponge
Asconoid Simple continuous choanoderm
Syconoid simple folding of pinacoderm and choanoderm
Leuconoid folding and subdivision of choanoderm
What is the reproduction of Porifera
Sexual reproduction so,e sponges are hermaphrodites so produce both male and females ,egg and sperm, produced at different times by the choanocytes and release via the aquiferous systems
Asexual reproduction fragmentation, budding and asexual larva
