Biology II test 3

• Spineless multicellular animals
• 95% of all animals
• Occupy all habitats - Adaptive radiation led to diversity
• ex. Insects and parasites

• Simplest multicellular animal- Sessile (attached, non moving) suspension feeder
• No true tissues, just specialized cells
• Filter dilute (eat) particles through an aquiferous system
• Asymmetrical

"Parent" cells type, similar to Human stem cells, that haven't been specialized.

Suck water into spongocoel (central cavity) through the ostia (incurrent pores) holes

Choanocytes (flaggellated cells along the spongocoel - central cavity) and Amoebocytes (multifunctional and totipotents)

The skeleton is made up of either Spicules (scattered framework made of CaCO3, calcium carbonate, or SiO2, silicon dioxide) or Spongin (soft, non scratchy fiberous proteins)

• Sting capability
• Radial Symmetry
• Diploblastic - ectoderm -> mesoglea -> endoderm
• Gastrovascular cavity - "blind" gut cavity, where the mouth is also the anus
• Polyp and Medusa
• 4 Classes

• Flower like stage - mouth up
• Solitary or Colonial
• Specialized feeding using tentacles around mouth.
• Cnidocytes - stinging cells on the tentacle
• Nomatocyst discharges - threads that wrap around/penetrate prey then release neurotoxin/poison.

Umbrella or bell like stage - mouth down

• Capable of alter between Polyp and Medusa depends on the living condition.
• Capable of asexual and sexual reproduction

• True Jellies
• Medusa stage dominated
• Polyp reduced at coastal area
• Polyp lost at open ocean area

• Similar to Scyphozoa except "Box" shape
• Most deadliest, but sea turtle can eat these in large quantities
• Retractable tentacles

• Anemones and Corals
• Polyp stage only
• Solitary or Colonial
• Coral is the skeleton. New member builds on old skeletons.