Flashcards in Chapter 33: Invertebrates Deck (30)
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1
Introduction
- Animals that lack backbone are called invertebrates
- account for 95% of animal species

2
Sponges
- Belong to Phylum Porifera
- Lack true tissues, organs
- Suspension feeders
- Hermaphrodites – Male/Female

3
Cnidarians
- Belong to Phylum Cnidaria
-
Clade Eumetazoa - True tissue
- Diploblastic, radial symmetry
- Two body plan
- 1. Polyp
- 2. Medusa
- 1. Polyp
- 2. Medusa

4
2 Major Clades of Cnidarians
-
1. Medusozoa
- members produce a medusa
-
2. Anthozoa
- members only occur in polyps
- members produce a medusa
- members only occur in polyps
5
Medusozoans
- Has 3 Groups:
-
Scyphozoans - true jellyfish
-
Cubazoans - box jellies
-
Hydrozoans - Hydra, Obelia
- Scyphozoans - true jellyfish
- Cubazoans - box jellies
- Hydrozoans - Hydra, Obelia

6
Anthozoans
- Include sea anemones, corals
- hard exoskeleton of calcium carbonate

7
Lophotrochozoa
- Clade characterized by
- 1. Lophophore
- 2. Trochophore larva
- Has six major phyla *
- 1. Lophophore
- 2. Trochophore larva

8
Flatworms
- Belong to Phylum Platyhelminthes
- Include:
- 1. Planarians
- 2. Trematodes - flukes
- 3. Tapeworms
- 1. Planarians
- 2. Trematodes - flukes
- 3. Tapeworms

9
Rotifers
- Belong to Phylum Rotifera
- Reproduce by parthenogenesis
- offspring from unfertilized eggs
- Some species lack males entirely
- offspring from unfertilized eggs

10
Lophophorates
- Have crown of ciliated tentacles around mouth
- Used in suspension feeding
- Include phyla:
- 1. Ectoprocta - “moss animals”
- 2. Brachiopoda - “lamp shells”
- 1. Ectoprocta - “moss animals”
- 2. Brachiopoda - “lamp shells”

11
Molluscs
- Belong to Phylum Mollusca
-
2nd largest animal phlya
- Most have shell
- Body w/ 3 main parts
- 1. Foot
- 2. Visceral mass
- 3. Mantle
- 1. Foot
- 2. Visceral mass
- 3. Mantle
12
Molluscs cont...
- Include clades
- 1. Polyplacophora - chitons
- 2. Gastropoda
- 3. Bivalvia
- 4. Cephalopoda
- 1. Polyplacophora - chitons
- 2. Gastropoda
- 3. Bivalvia
- 4. Cephalopoda
13
Chitons
- shell of eight dorsal plates

14
Gastropods
- Most have singled, spiral shell

15
Bivalves
- Shells in two halves, hinged

16
Cephalopods
- Have well developed sense organs, brains

17
Annelids
- Belong to Phylum Annelida
- Are segmented worms
- Groups include
- 1. Leeches
- 2. Earthworms
- 1. Leeches
- 2. Earthworms

18
Ecdysozoans
- Clade characterized by shedding of cuticle
- Process called ecdysis (molting)
- Two major phyla
- 1. Nematoda
- 2. Arthropoda
- 1. Nematoda
- 2. Arthropoda
19
Nematodes
- belong to Phylum Nematoda
- called roundworms; many parasitic members

20
Arthropods
- Belong to Phylum Arthropoda
- Probably 1 billion + species
- Body characteristics
- 1. Segmented body
- 2. Hard exoskeleton
- 3. Jointed appendages
- 1. Segmented body
- 2. Hard exoskeleton
- 3. Jointed appendages
21
Arthropod Anatomy

22
Arthropods cont...
- Three major lineages
- 1. Chelicerates
- 2. Myriapods
- 3. Pancrustaceans
- 1. Chelicerates
- 2. Myriapods
- 3. Pancrustaceans
23
Chelicerates
- Include spiders, scorpions, ticks, mites, horse crabs
- Named after feeding appendages (chelicerae)
- serve as pincers or fangs
- Head lacks antennae
- serve as pincers or fangs
24
Arachnids (group of chelicerates)
- Bulk of chelicerates
- Six pair of appendages
- Spiders: construct silk webs

25
Myriapods
- Include
- 1. Centipedes
- carnivores
- poisonous claws
- 2. Millipedes
- feed on plant matter
- 1. Centipedes
- carnivores
- poisonous claws
- 2. Millipedes
- feed on plant matter

26
Pancrustaceans
- Newly formed clade
- Two groups
- 1. Crustaceans
- 2. Hexapods - insects
- 1. Crustaceans
- 2. Hexapods - insects
27
Crustaceans (pancrustaceans)
- Include crabs, lobsters, shrimp, barnacles
- Two pair of antennae

28
Hexapods (pancrustaceans)

- Over 900,000 species
- Head, thorax, abdomen
- Six legged - 3 pair
- 1 or 2 pairs of wings
- Undergo metamorphosis

29
Deuterostomia
- Shares embryological characteristics
- Though primarily grouped by DNA
- Two major groups
- 1. Echinoderms
- 2. Chordates
- 1. Echinoderms
- 2. Chordates
30
Echinoderms
- Belong to Phylum Echinodermata
- Slow moving, sessile
- Display radial symmetry as adults
- Include sea stars, sea urchins
