Invertebrate Notes. Sponges- Porifera “Pore Bearer” Show examples Evolutionary sideline - alone....

Invertebrate Notes

Sponges- Porifera “Pore Bearer”Show examples• Evolutionary sideline - alone. • Simple multicellular animals lacking true

tissues or organs. • Sponges evolve from colonial flagellated

protists• Benthic and sessile as adults.• Height ranges from 1cm. - 2m.• Water drawn in through pores in body and

expelled out osculum. Flagella create current.

• Filter feeders, they can filter 100 liters of seawater an hour.

• Choanocytes (collar cell) phagocytize food on inside (flagellated cell)

• Amoebocytes digest and carry nutrients from choanocytes to epidermal cells.

• Amoebocytes also form skeletal fibers - spicules (CaCO3 or silica) or spongin (protein).

• Sexual Reproduction - hermaphrodites with cross fertilization. Flagellated larvas swim and find hard substrate. Planktonic in early stages.

• Asexual reproduction -

1. Extensive regeneration

2. Fragmentation or budding