MSCI 210 Lecture Notes - Lecture 16: Flatworm, Mollusca, Bioluminescence
Document Summary
Global distribution of benthic biomass: distribution pattern of benthic biomass follows primary productivity in surface waters, organic production sinks to sea floor. Three types of symmetry: asymmetrical - no symmetry, radial - cut in half across both ways, bilateral - only cut in one plane to make it symmetrical. Major invertebrate phyla: 1) phylum porifera. Have choanocyte cells that have tails to capture food while it filters water. Most primitive animals, no organs: 2) phylum ctenophora. Harmless bioluminescent jellies: 3) phylum cnidaria. Aka sea jellies, sea anemones, and corals. Members of this group have stinging cells. No organs: 4) phylum platyhelminthes the flatworms. Simple, but can regenerate their head if cut off: 5) phylum annelida the segmented worms. Soft bodied animals with a large foot. Pentamerous radial symmetry: 8) phylum arthropoda. Starfish are closely related to humans, moreso than any other marine invertebrate. Benthic organisms and distribution: the type of substrate determines the community composition, various lifestyles:
