Invertebrate Animals

Outline

Sponges, Phylum Porifera

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Animal Life

• Four critical processes• Obtain energy and material• Ingest, digest, absorb

• Obtain oxygen

• Dispose of nitrogenous waste• NH3, urea, uric acid

• Dispose of CO2

• Easy for 1-few cells

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Animal Life • Harder for multicellular organisms

• Large multicellular organisms require • Internal circulation

• Coordination, information transfer

• Structural maintenance

• Movement

• Maintenance of homeostatic internal environment

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Animal Life • We will study 9 Phyla in order of

increasing complexity.

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Animal Life • Outline for each Phylum:• Name and etymology

• General characters• Body plan and example

• Gut, symmetry, etc.

• Cell and tissue organization

• Special, unique “distinguishing” characters

• Where & how they live

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Animal Life

• Outline for each Phylum (continued):• Special concerns of a multicellular animal• Food, gas exchange, waste removal

• Circulation, Coordination, Structural support, Movement, Maintenance of homeostasis—water balance.

• Reproduction

• Classes (and Orders ?) • Distinguishing the Classes

Animal Life Geologic Time Scale

(Table 25.1, page 527)

Names of Eras in order

Names of Periods and Epochs, associated with Era

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Animal Life

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• Early fossil record of animals

• Simplest animals• Sponges

• Cnidarians

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Phylum Porifera

• Phylum Porifera (Calcarea + Silicea)• “pore bearers”

• No symmetry; may resemble radial symmetry

• Marine, freshwater

• Cells• Four kinds: “epidermal,” amoebocytes,

porocytes, choanocytes

Phylum Porifera

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• Unique characters• Choanocytes (collar cells)

• Cell body, flagellum, collar

• Feeding cells

• Shared with choanoflagellates• Are sponges animals ?

• Spicules

• Spongocoel & osculum

Phylum Porifera

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• Special concerns • Food

• O2 and CO2 exchange

• Waste removal

• Water flow

Phylum Porifera

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• Special concerns: • Water flow for circulation

• Little coordination• Chemical communication,

• no nerve cells

• Skeletons of CaCO3, SiO2, spongin

• Little movement, • no muscle cells

• Each cell maintains itself

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Phylum Porifera

• Reproduction• Sequential hermaphrodites

• Asexual

• Classification uncertain (polyphyletic ?)

• Classes based on nature of skeleton • Spicules of CaCO3

• Spongin

• Both

• Spicules of SiO2