Chapter 33 Presentation
Transcript of Chapter 33 Presentation
![Page 1: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/1.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
PowerPoint® Lecture Presentations for
Biology Eighth Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp
Chapter 33Chapter 33
Invertebrates
![Page 2: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/2.jpg)
Fig. 33-1
![Page 3: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/3.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Overview: Life Without a Backbone
• Invertebrates are animals that lack a backbone
• They account for 95% of known animal species
![Page 4: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/4.jpg)
Fig. 33-2
ANCESTRALPROTIST
Commonancestor ofall animals
Calcareaand Silicea
Eu
me
tazo
a
Bila
teria
Cnidaria
Lophotrochozoa
Ecdysozoa
Deuterostomia
![Page 5: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/5.jpg)
Fig. 33-3-1Calcarea and Silicea (5,500 species)
A sponge
Cnidaria (10,000 species)
A jelly
Acoela (400 species)
Acoel flatworms (LM)
1.5 mm
LOPHOTROCHOZOANS
Platyhelminthes (20,000 species)
A marine flatworm
Ectoprocta (4,500 species)
Ectoprocts A brachiopod
Brachiopoda (335 species)
Rotifera (1,800 species)
A rotifer (LM)
A ctenophore, or comb jelly
Ctenophora (100 species)
A placozoan (LM)
0.5 mm
Placozoa (1 species)
![Page 6: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/6.jpg)
Fig. 33-3-2
An acanthocephalan (LM)
Acanthocephala (1,100 species)
Nemertea (900 species)
A ribbon worm
ECDYSOZOA
Loricifera (10 species) Priapula (16 species)
A loriciferan (LM) A priapulan
50 µm
Cycliophora (1 species)
Mollusca (93,000 species)
A cycliophoran (colorized SEM)
100 µm
An octopus
Annelida (16,500 species)
A marine annelid
![Page 7: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/7.jpg)
Fig. 33-3-3Tardigrada (800 species)
Nematoda (25,000 species)
Onychophora (110 species)
Arthropoda (1,000,000 species)
DEUTEROSTOMIA
Hemichordata (85 species)
Echinodermata (7,000 species) Chordata (52,000 species)
Tardigrades (colorized SEM)
100 µm
A roundworm
An acorn worm
A sea urchin
An onychophoran
A scorpion(an arachnid)
A tunicate
![Page 8: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/8.jpg)
Fig. 33-3a
A sponge
![Page 9: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/9.jpg)
Fig. 33-3b
A jelly
![Page 10: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/10.jpg)
Fig. 33-3c
A placozoan (LM)
0.5 mm
![Page 11: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/11.jpg)
Fig. 33-3d
A ctenophore, or comb jelly
![Page 12: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/12.jpg)
Fig. 33-3e
Acoel flatworms (LM)
1.5 mm
![Page 13: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/13.jpg)
Fig. 33-3f
A marine flatworm
![Page 14: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/14.jpg)
Fig. 33-3g
A rotifer (LM)
![Page 15: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/15.jpg)
Fig. 33-3h
Ectoprocts
![Page 16: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/16.jpg)
Fig. 33-3i
A brachiopod
![Page 17: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/17.jpg)
Fig. 33-3j
An acanthocephalan (LM)
![Page 18: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/18.jpg)
Fig. 33-3k
A cycliophoran (colorized SEM)
100 µm
![Page 19: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/19.jpg)
Fig. 33-3l
A ribbon worm
![Page 20: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/20.jpg)
Fig. 33-3m
An octopus
![Page 21: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/21.jpg)
Fig. 33-3n
A marine annelid
![Page 22: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/22.jpg)
Fig. 33-3o
A loriciferan (LM)
50 µm
![Page 23: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/23.jpg)
Fig. 33-3p
A priapulan
![Page 24: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/24.jpg)
Fig. 33-3q
Tardigrades (colorized SEM)
100 µm
![Page 25: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/25.jpg)
Fig. 33-3r
An onychophoran
![Page 26: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/26.jpg)
Fig. 33-3s
A roundworm
![Page 27: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/27.jpg)
Fig. 33-3t
A scorpion(an arachnid)
![Page 28: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/28.jpg)
Fig. 33-3u
An acorn worm
![Page 29: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/29.jpg)
Fig. 33-3v
A sea urchin
![Page 30: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/30.jpg)
Fig. 33-3w
A tunicate
![Page 31: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/31.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 33.1: Sponges are basal animals that lack true tissues
• Sponges are sedentary animals from the phyla Calcarea and Silicea
• They live in both fresh and marine waters
• Sponges lack true tissues and organs
![Page 32: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/32.jpg)
Fig. 33-UN1
Calcarea and Silicea
CnidariaLophotrochozoa
Ecdysozoa
Deuterostomia
![Page 33: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/33.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Sponges are suspension feeders, capturing food particles suspended in the water that pass through their body
• Choanocytes, flagellated collar cells, generate a water current through the sponge and ingest suspended food
• Water is drawn through pores into a cavity called the spongocoel, and out through an opening called the osculum
![Page 34: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/34.jpg)
Fig. 33-4
Azure vase sponge (Callyspongiaplicifera)
Spongocoel
Osculum
Pore
Epidermis Waterflow
Mesohyl
Choanocyte
Flagellum
Collar
Food particlesin mucus
Choanocyte
AmoebocytePhagocytosis offood particles
Spicules
Amoebocytes
![Page 35: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/35.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Sponges consist of a noncellular mesohyl layer between two cell layers
• Amoebocytes are found in the mesohyl and play roles in digestion and structure
• Most sponges are hermaphrodites: Each individual functions as both male and female
![Page 36: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/36.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 33.2: Cnidarians are an ancient phylum of eumetazoans
• All animals except sponges and a few other groups belong to the clade Eumetazoa, animals with true tissues
• Phylum Cnidaria is one of the oldest groups in this clade
![Page 37: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/37.jpg)
Fig. 33-UN2
Calcarea and Silicea
CnidariaLophotrochozoa
Ecdysozoa
Deuterostomia
![Page 38: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/38.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Cnidarians have diversified into a wide range of both sessile and motile forms including jellies, corals, and hydras
• They exhibit a relatively simple diploblastic, radial body plan
![Page 39: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/39.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The basic body plan of a cnidarian is a sac with a central digestive compartment, the gastrovascular cavity
• A single opening functions as mouth and anus
• There are two variations on the body plan: the sessile polyp and motile medusa
![Page 40: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/40.jpg)
Fig. 33-5
PolypMouth/anus
Bodystalk
Tentacle
Gastrovascularcavity
Gastrodermis
Mesoglea
Epidermis
TentacleMouth/anus
Medusa
![Page 41: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/41.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Cnidarians are carnivores that use tentacles to capture prey
• The tentacles are armed with cnidocytes, unique cells that function in defense and capture of prey
• Nematocysts are specialized organelles within cnidocytes that eject a stinging thread
![Page 42: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/42.jpg)
Fig. 33-6
Tentacle
Nematocyst
“Trigger”
Cuticleof prey
Threaddischarges
Thread(coiled)
Cnidocyte
Thread
![Page 43: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/43.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Phylum Cnidaria is divided into four major classes:
– Hydrozoa
– Scyphozoa
– Cubozoa
– Anthozoa
![Page 44: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/44.jpg)
Table 33-1
![Page 45: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/45.jpg)
Fig. 33-7
(a) Colonial polyps (class Hydrozoa)
(b) Jellies (class Scyphozoa)
Sea wasp (classCubozoa)
(d) Sea anemone (class Anthozoa)
(c)
![Page 46: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/46.jpg)
Fig. 33-7a
(a) Colonial polyps (class Hydrozoa)
![Page 47: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/47.jpg)
Fig. 33-7b
(b) Jellies (class Scyphozoa)
![Page 48: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/48.jpg)
Fig. 33-7c
(c) Sea wasp (class Cubozoa)
![Page 49: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/49.jpg)
Fig. 33-7d
(d) Sea anemone (class Anthozoa)
![Page 50: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/50.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Hydrozoans
• Most hydrozoans alternate between polyp and medusa forms
Video: Hydra BuddingVideo: Hydra Budding
Video: Hydra Releasing SpermVideo: Hydra Releasing Sperm
Video: Hydra Eating Daphnia (time lapse)Video: Hydra Eating Daphnia (time lapse)
![Page 51: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/51.jpg)
Fig. 33-8-1
Feedingpolyp
Reproductivepolyp
Medusabud
Medusa
ASEXUALREPRODUCTION(BUDDING)Portion of
a colonyof polyps
1 m
m
Key
Haploid (n)Diploid (2n)
![Page 52: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/52.jpg)
Fig. 33-8-2
Feedingpolyp
Reproductivepolyp
Medusabud
Medusa
ASEXUALREPRODUCTION(BUDDING)Portion of
a colonyof polyps
1 m
m
Key
Haploid (n)Diploid (2n)
Gonad
SEXUALREPRODUCTION
MEIOSIS
FERTILIZATION
Egg Sperm
Zygote
![Page 53: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/53.jpg)
Fig. 33-8-3
Feedingpolyp
Reproductivepolyp
Medusabud
Medusa
ASEXUALREPRODUCTION(BUDDING)Portion of
a colonyof polyps
1 m
m
Key
Haploid (n)Diploid (2n)
Gonad
SEXUALREPRODUCTION
MEIOSIS
FERTILIZATION
Egg Sperm
Zygote
Planula(larva)
Developingpolyp
Maturepolyp
![Page 54: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/54.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Scyphozoans
• In the class Scyphozoa, jellies (medusae) are the prevalent form of the life cycle
Video: Jelly SwimmingVideo: Jelly Swimming
Video: Thimble JelliesVideo: Thimble Jellies
![Page 55: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/55.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cubozoans
• In the class Cubozoa, which includes box jellies and sea wasps, the medusa is box-shaped and has complex eyes
• Cubozoans often have highly toxic cnidocytes
![Page 56: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/56.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Anthozoans
• Class Anthozoa includes the corals and sea anemones, which occur only as polyps
Video: Clownfish and AnemoneVideo: Clownfish and Anemone
Video: Coral ReefVideo: Coral Reef
![Page 57: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/57.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 33.3: Lophotrochozoans, a clade identified by molecular data, have the widest range of animal body forms
• Bilaterian animals have bilateral symmetry and triploblastic development
• The clade Bilateria contains Lophotrochozoa, Ecdysozoa, and Deuterostomia
![Page 58: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/58.jpg)
Fig. 33-UN3
Calcarea and Silicea
CnidariaLophotrochozoa
Ecdysozoa
Deuterostomia
![Page 59: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/59.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The clade Lophotrochozoa was identified by molecular data
• Some develop a lophophore for feeding, others pass through a trochophore larval stage, and a few have neither feature
• Lophotrochozoa includes the flatworms, rotifers, ectoprocts, brachiopods, molluscs, and annelids
![Page 60: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/60.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Flatworms
• Members of phylum Platyhelminthes live in marine, freshwater, and damp terrestrial habitats
• Although flatworms undergo triploblastic development, they are acoelomates
• They are flattened dorsoventrally and have a gastrovascular cavity
• Gas exchange takes place across the surface, and protonephridia regulate the osmotic balance
![Page 61: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/61.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Flatworms are divided into four classes:
– Turbellaria (mostly free-living flatworms)
– Monogenea (monogeneans)
– Trematoda (trematodes, or flukes)
– Cestoda (tapeworms)
![Page 62: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/62.jpg)
Table 33-2
![Page 63: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/63.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Turbellarians
• Turbellarians are nearly all free-living and mostly marine
• The best-known turbellarians are commonly called planarians
![Page 64: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/64.jpg)
Fig. 33-9
![Page 65: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/65.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Planarians have light-sensitive eyespots and centralized nerve nets
• The planarian nervous system is more complex and centralized than the nerve nets of cnidarians
• Planarians are hermaphrodites and can reproduce sexually, or asexually through fission
![Page 66: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/66.jpg)
Fig. 33-10
Pharynx
Gastrovascularcavity
Mouth
Eyespots
Ganglia Ventral nerve cords
![Page 67: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/67.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Monogeneans and Trematodes
• Monogeneans and trematodes live as parasites in or on other animals
• They parasitize a wide range of hosts, and most have complex life cycles with alternating sexual and asexual stages
• Trematodes that parasitize humans spend part of their lives in snail hosts
• Most monogeneans are parasites of fish
![Page 68: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/68.jpg)
Fig. 33-11
Human host
Motile larva
Snail host
Ciliated larva
Male
Female
1 mm
![Page 69: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/69.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Tapeworms
• Tapeworms are parasites of vertebrates and lack a digestive system
• Tapeworms absorb nutrients from the host’s intestine
• Fertilized eggs, produced by sexual reproduction, leave the host’s body in feces
![Page 70: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/70.jpg)
Fig. 33-12
Proglottids withreproductive structures
Hooks
Sucker
Scolex
200 µm
![Page 71: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/71.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Rotifers
• Rotifers, phylum Rotifera, are tiny animals that inhabit fresh water, the ocean, and damp soil
• Rotifers are smaller than many protists but are truly multicellular and have specialized organ systems
Video: RotiferVideo: Rotifer
![Page 72: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/72.jpg)
Fig. 33-13
Jaws Crownof cilia
AnusStomach 0.1 mm
![Page 73: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/73.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Rotifers have an alimentary canal, a digestive tube with a separate mouth and anus that lies within a fluid-filled pseudocoelom
• Rotifers reproduce by parthenogenesis, in which females produce offspring from unfertilized eggs
• Some species are unusual in that they lack males entirely
![Page 74: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/74.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Lophophorates: Ectoprocts and Brachiopods
• Lophophorates have a lophophore, a horseshoe-shaped, suspension-feeding organ with ciliated tentacles
• Lophophorates include two phyla: Ectoprocta and Brachiopoda
• Ectoprocts (also called bryozoans) are colonial animals that superficially resemble plants
• A hard exoskeleton encases the colony, and some species are reef builders
![Page 75: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/75.jpg)
Fig. 33-14
Lophophore
(a) Ectoproct (sea mat)
Lophophore
(b) Brachiopods
![Page 76: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/76.jpg)
Fig. 33-14a
(a) Ectoproct (sea mat)
Lophophore
![Page 77: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/77.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Brachiopods superficially resemble clams and other hinge-shelled molluscs, but the two halves of the shell are dorsal and ventral rather than lateral as in clams
![Page 78: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/78.jpg)
Fig. 33-14b
(b) Brachiopods
Lophophore
![Page 79: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/79.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Molluscs
• Phylum Mollusca includes snails and slugs, oysters and clams, and octopuses and squids
• Most molluscs are marine, though some inhabit fresh water and some are terrestrial
• Molluscs are soft-bodied animals, but most are protected by a hard shell
![Page 80: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/80.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• All molluscs have a similar body plan with three main parts:
– Muscular foot
– Visceral mass
– Mantle
• Many molluscs also have a water-filled mantle cavity, and feed using a rasplike radula
![Page 81: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/81.jpg)
Fig. 33-15
Nephridium Visceral mass
Coelom
Mantle
Mantlecavity
Heart
Intestine
Gonads
Stomach
Shell
Radula
MouthEsophagusNerve
cordsFoot
Gill
Anus
Mouth
Radula
![Page 82: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/82.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Most molluscs have separate sexes with gonads located in the visceral mass
• The life cycle of many molluscs includes a ciliated larval stage called a trochophore
![Page 83: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/83.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• There are four major classes of molluscs:
– Polyplacophora (chitons)
– Gastropoda (snails and slugs)
– Bivalvia (clams, oysters, and other bivalves)
– Cephalopoda (squids, octopuses, cuttlefish, and chambered nautiluses)
![Page 84: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/84.jpg)
Table 33-3
![Page 85: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/85.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Chitons
• Class Polyplacophora consists of the chitons, oval-shaped marine animals encased in an armor of eight dorsal plates
![Page 86: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/86.jpg)
Fig. 33-16
![Page 87: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/87.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Gastropods
• About three-quarters of all living species of molluscs are gastropods
Video: NudibranchsVideo: Nudibranchs
![Page 88: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/88.jpg)
Fig. 33-17
(a) A land snail
(b) A sea slug
![Page 89: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/89.jpg)
Fig. 33-17a
(a) A land snail
![Page 90: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/90.jpg)
Fig. 33-17b
(b) A sea slug
![Page 91: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/91.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Most gastropods are marine, but many are freshwater and terrestrial species
• Most have a single, spiraled shell
• Slugs lack a shell or have a reduced shell
• The most distinctive characteristic of gastropods is torsion, which causes the animal’s anus and mantle to end up above its head
![Page 92: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/92.jpg)
Fig. 33-18
Mouth
Anus
Mantlecavity
Stomach Intestine
![Page 93: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/93.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Bivalves
• Molluscs of class Bivalvia include many species of clams, oysters, mussels, and scallops
• They have a shell divided into two halves
![Page 94: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/94.jpg)
Fig. 33-19
![Page 95: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/95.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The mantle cavity of a bivalve contains gills that are used for feeding as well as gas exchange
![Page 96: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/96.jpg)
Fig. 33-20
Mouth
Digestivegland
MantleHinge area
Gut
Coelom
Heart Adductormuscle
Anus
Excurrentsiphon
Waterflow
IncurrentsiphonGillGonad
Mantlecavity
Foot
Palp
Shell
![Page 97: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/97.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cephalopods
• Class Cephalopoda includes squids and octopuses, carnivores with beak-like jaws surrounded by tentacles of their modified foot
• Most octopuses creep along the sea floor in search of prey
![Page 98: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/98.jpg)
Fig. 33-21
Octopus
Squid
Chambered nautilus
![Page 99: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/99.jpg)
Fig. 33-21a
Octopus
![Page 100: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/100.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Squids use their siphon to fire a jet of water, which allows them to swim very quickly
![Page 101: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/101.jpg)
Fig. 33-21b
Squid
![Page 102: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/102.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• One small group of shelled cephalopods, the nautiluses, survives today
![Page 103: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/103.jpg)
Fig. 33-21c
Chamberednautilus
![Page 104: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/104.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Cephalopods have a closed circulatory system, well-developed sense organs, and a complex brain
• Shelled cephalopods called ammonites were common but went extinct at the end of the Cretaceous
![Page 105: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/105.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Annelids
• Annelids have bodies composed of a series of fused rings
• The phylum Annelida is divided into three classes:
– Oligochaeta (earthworms and their relatives)
– Polychaeta (polychaetes)
– Hirudinea (leeches)
![Page 106: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/106.jpg)
Table 33-4
![Page 107: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/107.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Oligochaetes
• Oligochaetes (class Oligochaeta) are named for relatively sparse chaetae, bristles made of chitin
• They include the earthworms and a variety of aquatic species
• Earthworms eat through soil, extracting nutrients as the soil moves through the alimentary canal
• Earthworms are hermaphrodites but cross-fertilize
Video: Earthworm LocomotionVideo: Earthworm Locomotion
![Page 108: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/108.jpg)
Fig. 33-22
Epidermis
Circularmuscle
Longitudinalmuscle
Dorsal vessel
Chaetae
Intestine
Nephrostome
Fusednervecords
Ventralvessel
Metanephridium
Septum(partitionbetweensegments)
CoelomCuticle
Anus
Metanephridium
Crop
Intestine
Gizzard
Ventral nerve cord withsegmental gangliaBlood
vessels
Subpharyngealganglion
MouthCerebral ganglia
Pharynx
Esophagus
Clitellum
Giant Australian earthworm
![Page 109: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/109.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Polychaetes
• Members of class Polychaetes have paddle-like parapodia that work as gills and aid in locomotion
Video: TubewormsVideo: Tubeworms
![Page 110: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/110.jpg)
Fig. 33-23
Parapodia
![Page 111: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/111.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Leeches
• Members of class Hirudinea are blood-sucking parasites, such as leeches
• Leeches secrete a chemical called hirudin to prevent blood from coagulating
![Page 112: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/112.jpg)
Fig. 33-24
![Page 113: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/113.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 33.4: Ecdysozoans are the most species-rich animal group
• Ecdysozoans are covered by a tough coat called a cuticle
• The cuticle is shed or molted through a process called ecdysis
• The two largest phyla are nematodes and arthropods
![Page 114: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/114.jpg)
Fig. 33-UN4
Calcarea and Silicea
CnidariaLophotrochozoa
Ecdysozoa
Deuterostomia
![Page 115: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/115.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nematodes
• Nematodes, or roundworms, are found in most aquatic habitats, in the soil, in moist tissues of plants, and in body fluids and tissues of animals
• They have an alimentary canal, but lack a circulatory system
• Reproduction in nematodes is usually sexual, by internal fertilization
Video: Video: C.C. eleganselegans Crawling Crawling
Video: Video: C.C. eleganselegans Embryo Development (Time Lapse) Embryo Development (Time Lapse)
![Page 116: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/116.jpg)
Fig. 33-25
25 µm
![Page 117: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/117.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Some species of nematodes are important parasites of plants and animals
![Page 118: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/118.jpg)
Fig. 33-26
Encysted juveniles Muscle tissue 50 µm
![Page 119: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/119.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Arthropods
• Two out of every three known species of animals are arthropods
• Members of the phylum Arthropoda are found in nearly all habitats of the biosphere
![Page 120: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/120.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Arthropod Origins
• The arthropod body plan consists of a segmented body, hard exoskeleton, and jointed appendages, and dates to the Cambrian explosion (535–525 million years ago)
• Early arthropods show little variation from segment to segment
![Page 121: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/121.jpg)
Fig. 33-27
![Page 122: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/122.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Arthropod evolution is characterized by a decrease in the number of segments and an increase in appendage specialization
• These changes may have been caused by changes in Hox gene sequence or regulation
![Page 123: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/123.jpg)
Fig. 33-28
EXPERIMENT
RESULTS
Origin of Ubx andabd-A Hox genes?
Otherecdysozoans
Arthropods
OnychophoransCommon ancestor ofonychophorans and arthropods
Ubx orabd-A genesexpressed
Ant = antennaJ = jawsL1–L15 = body segments
![Page 124: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/124.jpg)
Fig. 33-28a
EXPERIMENT
Otherecdysozoans
Origin of Ubx andabd-A Hox genes?
Common ancestor ofonychophorans and arthropods
Arthropods
Onychophorans
![Page 125: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/125.jpg)
Fig. 33-28b
RESULTS
Ubx orabd-A genesexpressed
Ant = antennaJ = jawsL1–L15 = body segments
![Page 126: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/126.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
General Characteristics of Arthropods
• The appendages of some living arthropods are modified for many different functions
Video: Lobster Mouth PartsVideo: Lobster Mouth Parts
![Page 127: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/127.jpg)
Fig. 33-29
Cephalothorax
Antennae(sensoryreception) Head
Thorax
Abdomen
Swimming appendages(one pair locatedunder eachabdominal segment)
Walking legs
Mouthparts (feeding)Pincer (defense)
![Page 128: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/128.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The body of an arthropod is completely covered by the cuticle, an exoskeleton made of layers of protein and the polysaccharide chitin
• When an arthropod grows, it molts its exoskeleton
![Page 129: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/129.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Arthropods have an open circulatory system in which fluid called hemolymph is circulated into the spaces surrounding the tissues and organs
• A variety of organs specialized for gas exchange have evolved in arthropods
![Page 130: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/130.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Molecular evidence suggests that living arthropods consist of four major lineages that diverged early in the phylum’s evolution:
– Cheliceriforms (sea spiders, horseshoe crabs, scorpions, ticks, mites, and spiders)
– Myriapods (centipedes and millipedes)
– Hexapods (insects and relatives)
– Crustaceans (crabs, lobsters, shrimps, barnacles, and many others)
![Page 131: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/131.jpg)
Table 33-5
![Page 132: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/132.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Cheliceriforms
• Cheliceriforms, subphylum Cheliceriformes, are named for clawlike feeding appendages called chelicerae
• The earliest cheliceriforms were eurypterids (water scorpions)
• Most marine cheliceriforms (including eurypterids) are extinct, but some species survive today, including horseshoe crabs
![Page 133: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/133.jpg)
Fig. 33-30
![Page 134: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/134.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Most modern cheliceriforms are arachnids, which include spiders, scorpions, ticks, and mites
![Page 135: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/135.jpg)
Fig. 33-31
Scorpion
Dust mite
Web-building spider
50 µm
![Page 136: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/136.jpg)
Fig. 33-31a
Scorpion
![Page 137: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/137.jpg)
Fig. 33-31b
Dust mite
50 µm
![Page 138: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/138.jpg)
Fig. 33-31c
Web-building spider
![Page 139: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/139.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Arachnids have an abdomen and a cephalothorax, which has six pairs of appendages, the most anterior of which are the chelicerae
• Gas exchange in spiders occurs in respiratory organs called book lungs
• Many spiders produce silk, a liquid protein, from specialized abdominal glands
![Page 140: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/140.jpg)
Fig. 33-32
Intestine
HeartDigestivegland
Ovary
Anus
Spinnerets
Silk gland
Gonopore(exit for eggs) Sperm
receptacle
Book lung
Chelicera Pedipalp
Poisongland
Eyes
Brain
Stomach
![Page 141: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/141.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Myriapods
• Subphylum Myriapoda includes millipedes and centipedes
– Myriapods are terrestrial, and have jaw-like mandibles
• Millipedes, class Diplopoda, have many legs
– Each trunk segment has two pairs of legs
![Page 142: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/142.jpg)
Fig. 33-33
![Page 143: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/143.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Centipedes, class Chilopoda, are carnivores
– They have one pair of legs per trunk segment
![Page 144: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/144.jpg)
Fig. 33-34
![Page 145: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/145.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Insects
• Subphylum Hexapoda, insects and relatives, has more species than all other forms of life combined
• They live in almost every terrestrial habitat and in fresh water
• The internal anatomy of an insect includes several complex organ systems
![Page 146: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/146.jpg)
Fig. 33-35
Abdomen Thorax Head
Compound eye
Antennae
Heart
Dorsalartery Crop
Cerebral ganglion
Mouthparts
Nerve cords
Tracheal tubesOvary
Malpighiantubules
Vagina
Anus
![Page 147: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/147.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Insects diversified several times following the evolution of flight, adaptation to feeding on gymnosperms, and the expansion of angiosperms
• Insect and plant diversity declined during the Cretaceous extinction, but have been increasing in the 65 million years since
![Page 148: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/148.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Flight is one key to the great success of insects
• An animal that can fly can escape predators, find food, and disperse to new habitats much faster than organisms that can only crawl
![Page 149: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/149.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Many insects undergo metamorphosis during their development
• In incomplete metamorphosis, the young, called nymphs, resemble adults but are smaller and go through a series of molts until they reach full size
![Page 150: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/150.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Insects with complete metamorphosis have larval stages known by such names as maggot, grub, or caterpillar
• The larval stage looks entirely different from the adult stage
Video: Butterfly EmergingVideo: Butterfly Emerging
![Page 151: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/151.jpg)
Fig. 33-36
(a) Larva (caterpillar)(b) Pupa
(c) Later-stage pupa (d) Emerging
adult
(e) Adult
![Page 152: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/152.jpg)
Fig. 33-36a
(a) Larva (caterpillar)
![Page 153: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/153.jpg)
Fig. 33-36b
(b) Pupa
![Page 154: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/154.jpg)
Fig. 33-36c
(c) Later-stage pupa
![Page 155: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/155.jpg)
Fig. 33-36d
(d) Emerging adult
![Page 156: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/156.jpg)
Fig. 33-36e
(e) Adult
![Page 157: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/157.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Most insects have separate males and females and reproduce sexually
• Individuals find and recognize members of their own species by bright colors, sound, or odors
• Some insects are beneficial as pollinators, while others are harmful as carriers of diseases, or pests of crops
• Insects are classified into more than 30 orders
Video: Bee PollinatingVideo: Bee Pollinating
![Page 158: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/158.jpg)
Fig. 33-37
![Page 159: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/159.jpg)
Fig. 33-37a
![Page 160: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/160.jpg)
Fig. 33-37b
![Page 161: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/161.jpg)
Fig. 33-37c
![Page 162: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/162.jpg)
Fig. 33-37d
![Page 163: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/163.jpg)
Fig. 33-37e
![Page 164: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/164.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Crustaceans
• While arachnids and insects thrive on land, crustaceans, for the most part, have remained in marine and freshwater environments
• Crustaceans, subphylum Crustacea, typically have branched appendages that are extensively specialized for feeding and locomotion
• Most crustaceans have separate males and females
![Page 165: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/165.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Isopods include terrestrial, freshwater, and marine species
– Pill bugs are a well known group of terrestrial isopods
• Decapods are all relatively large crustaceans and include lobsters, crabs, crayfish, and shrimp
![Page 166: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/166.jpg)
Fig. 33-38
(a) Ghost crab
(b) Krill (c) Barnacles
![Page 167: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/167.jpg)
Fig. 33-38a
(a) Ghost crab
![Page 168: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/168.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Planktonic crustaceans include many species of copepods, which are among the most numerous of all animals
![Page 169: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/169.jpg)
Fig. 33-38b
(b) Krill
![Page 170: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/170.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Barnacles are a group of mostly sessile crustaceans
• They have a cuticle that is hardened into a shell
![Page 171: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/171.jpg)
Fig. 33-38c
(c) Barnacles
![Page 172: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/172.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Concept 33.5: Echinoderms and chordates are deuterostomes
• Sea stars and other echinoderms, phylum Echinodermata, may seem to have little in common with phylum Chordata, which includes the vertebrates
• Shared characteristics define deuterostomes (Chordates and Echinoderms)
– Radial cleavage
– Formation of the mouth at the end of the embryo opposite the blastopore
![Page 173: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/173.jpg)
Fig. 33-UN5
Calcarea and Silicea
CnidariaLophotrochozoa
Ecdysozoa
Deuterostomia
![Page 174: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/174.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Echinoderms
• Sea stars and most other echinoderms are slow-moving or sessile marine animals
• A thin epidermis covers an endoskeleton of hard calcareous plates
• Echinoderms have a unique water vascular system, a network of hydraulic canals branching into tube feet that function in locomotion, feeding, and gas exchange
• Males and females are usually separate, and sexual reproduction is external
![Page 175: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/175.jpg)
Fig. 33-39
AnusStomach
Spine
Gills
Madreporite
Radialnerve
Gonads
Ampulla
Podium
Tubefeet
Radial canal
Ringcanal
Central disk
Digestive glands
![Page 176: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/176.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Video: Echinoderm Tube FeetVideo: Echinoderm Tube Feet
• Living echinoderms are divided into six classes:
– Asteroidia (sea stars)
– Ophiuroidea (brittle stars)
– Echinoidea (sea urchins and sand dollars)
– Crinoidea (sea lilies and feather stars)
– Holothuroidea (sea cucumbers)
– Concentricycloidea (sea daisies)
![Page 177: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/177.jpg)
Table 33-6
![Page 178: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/178.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Sea Stars
• Sea stars, class Asteroidea, have multiple arms radiating from a central disk
• The undersurfaces of the arms bear tube feet, each of which can act like a suction disk
• Sea stars can regrow lost arms
![Page 179: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/179.jpg)
Fig. 33-40
(a) A sea star (class Asteroidea)
(c) A sea urchin (class Echinoidea)
(e) A sea cucumber (class Holothuroidea)
(b) A brittle star (class Ophiuroidea)
(d) A feather star (class Crinoidea)
(f) A sea daisy (class Concentricycloidea)
![Page 180: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/180.jpg)
Fig. 33-40a
(a) A sea star (class Asteroidea)
![Page 181: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/181.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Brittle Stars
• Brittle stars have a distinct central disk and long, flexible arms, which they use for movement
![Page 182: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/182.jpg)
Fig. 33-40b
(b) A brittle star (class Ophiuroidea)
![Page 183: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/183.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Sea Urchins and Sand Dollars
• Sea urchins and sand dollars have no arms but have five rows of tube feet
![Page 184: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/184.jpg)
Fig. 33-40c
(c) A sea urchin (class Echinoidea)
![Page 185: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/185.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Sea Lilies and Feather Stars
• Sea lilies live attached to the substrate by a stalk
• Feather stars can crawl using long, flexible arms
![Page 186: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/186.jpg)
Fig. 33-40d
(d) A feather star (class Crinoidea)
![Page 187: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/187.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Sea Cucumbers
• Sea cucumbers lack spines, have a very reduced endoskeleton, and do not look much like other echinoderms
• Sea cucumbers have five rows of tube feet; some of these are developed as feeding tentacles
![Page 188: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/188.jpg)
Fig. 33-40e
(e) A sea cucumber (class Holothuroidea)
![Page 189: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/189.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Sea Daisies
• Sea daisies were discovered in 1986, and only three species are known
![Page 190: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/190.jpg)
Fig. 33-40f
(f) A sea daisy (class Concentricycloidea)
![Page 191: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/191.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Chordates
• Phylum Chordata consists of two subphyla of invertebrates as well as hagfishes and vertebrates
• Chordates share many features of embryonic development with echinoderms, but have evolved separately for at least 500 million years
![Page 192: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/192.jpg)
Fig. 33-UN6
![Page 193: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/193.jpg)
Fig. 33-UN6a
![Page 194: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/194.jpg)
Fig. 33-UN6b
![Page 195: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/195.jpg)
Fig. 33-UN6c
![Page 196: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/196.jpg)
Fig. 33-UN6d
![Page 197: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/197.jpg)
Fig. 33-UN6e
![Page 198: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/198.jpg)
Fig. 33-UN7
![Page 199: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/199.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
You should now be able to:
1. Describe how a sponge feeds and digests its food
2. List the characteristics of the phylum Cnidaria that distinguish it from other animal phyla
3. List the four classes of Cnidaria and distinguish among them based on life cycle morphology
4. List the characteristics of Platyhelminthes and distinguish among the four classes
![Page 200: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/200.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
5. Describe a lophophore and name two lophophorate phyla
6. Describe the features of molluscs and distinguish among the four classes
7. Describe the features of annelids and distinguish among the three classes
8. List the characteristics of nematodes that distinguish them from other wormlike animals
![Page 201: Chapter 33 Presentation](https://reader034.fdocuments.in/reader034/viewer/2022052522/554980cbb4c90582588b4ad2/html5/thumbnails/201.jpg)
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
9. List three features that account for the success of arthropods
10. Define and distinguish among the four major arthropod lineages
11. Describe the developmental similarities between echinoderms and chordates
12. Distinguish among the six classes of echinoderms