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Animal Diversity I. BIOB 171. Background. Domain Eukarya , Kingdom Animalia Heterotrophic – obtain food by ingesting other organisms or their by-products Lack cell walls Pass through a blastula stage Arose approx. 620 - 550 mya 35 major groups (we will look at 9). Parazoa. - PowerPoint PPT Presentation
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Animal Diversity I
BIOB 171
Background
• Domain Eukarya, Kingdom Animalia
• Heterotrophic – obtain food by ingesting other organisms or
their by-products
• Lack cell walls
• Pass through a blastula stage
• Arose approx. 620 - 550 mya
• 35 major groups (we will look at 9)
Parazoa
Rotifera??
Eumetazoa• All multicellular animals
• Organisms in this group have either radial or bilateral symmetry
Two developmental trajectories in Eumetazoa:
That’s us!
Hydras aren’t any of these…. Super simple design with 2 layersRotifers are pseudocoelomate
Protostomes
• Two large groups:– Lophotrochozoa – The name is based on the trochophore larva found in
within this group. Includes annelids, molluscs, flatworms, and maybe rotifers– Ecdysozoa – Animals in this group undergo molting (ecdysis) or the shedding
of an outer body cover. Includes roundworms, nematodes, arthropods (like insects, and more).
Today…We will be looking at these organisms…
– Hydra (Cnidaria)
– Rotifers (Rotifera)
Why? Because the lecture needs to catch up to the lab!
Basic CharacteristicsPages 181 – 183
• Read through and understand all 13 characteristics
• As you perform the dissections and look at organisms today, refer to these characteristics.
• Observe the animal and record your observations in the summary table on PAGE 224
Phylum Cnidaria – Hydras (Hydra)• Two tissue types, no complex organs
• Includes: corals, jellies, sea anemones, and Portuguese men-of-war.
• Most species are marine, few freshwater spp.
• Two body forms present in the life cycle:– Umbrella-like, free-swimming stage– Cylindrical, attached or stationary form – often grows into colonies of
individuals
• Observe live hydra in a depression slide and try to feed Daphnia or liver juice with string
• Also observe prepared slides
Phylum Rotifera - Rotifers
• NOT IN LAB MANUAL
• Very small animals – most 0.1 – 0.5 mm in length
• Most common in freshwater, though some salt water species
• Important part of freshwater zooplankton, being a major food source and many species contributing to decomposition of organic matter.
• Pharynx contains tiny, calcified, jaw-like structure called trophi
Last minute thoughts…• Be sure to record your observations in the Table on page 224
(might be better to reproduce in your lab notebook).
• If you have questions about your papers, please ask. Turn in your rough drafts (if you want feedback) by Friday.