Biology, Seventh Edition
Solomon • Berg • Martin
Chapter 29
The Animal Kingdom:
The Protostomes
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Characteristics of protostome
coelomates
• Spiral cleavage
• Determinate cleavage
• Development of the mouth from
the blastosphore
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Characteristics of protostome
coelomates, cont.
• Coelom is a fluid-filled cavity
lined with mesoderm
• Evolution of the coelom permitted
many innovations, including
–Tube-within-a-tube body plan
–Hydrostatic skeleton
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Characteristics of protostome
coelomates, cont.
• Coelom provides space for
development of internal organs
and gonads
• Coelom helps transport materials
and protects internal organs
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Protostome coelomates include
two main branches
• Lophotrochozoa
• Ecdysozoa
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Lophotrochozoa
• Platyhelminthes
• Nemerteans
• Mollusks
• Annelids
• Lophophorate phyla
• Rotifers
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Longitudinal
section of rotifer
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Ecdysozoa
• Nematodes
• Arthropods
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Characteristics of phylum
Nemertea
• Proboscis
• Reduced coelom: rhynchocoel
• Tube-within-a-tube body plan
• Complete digestive tract
• Mouth with anus
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Lateral view of a typical nemertean
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Characteristics of phylum
Platyhelminthes
• Acoelomate
• Bilateral symmetry
• Cephalization
• Three definite tissue layers
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Characteristics of phylum
Platyhelminthes, cont.
• Well-developed organs
• Many are hermaphrodites
• Ladder-type nervous system
–Ganglia
• Protonephridia
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Phylum platyhelminthes
• Turbellaria
–Free-living flatworms including
planarians
• Trematoda and Monogenea
–Parasitic flukes
• Cestoda
–Parasitic tapeworms
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
The common planarian, Dugesia
Internal structure
LM of a living planarian, Dugesia
dorotocephala
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Parasitic flukes and tapeworms
typically have
• Suckers or hooks
• Complicated life cycles with
intermediate hosts
• Large numbers of eggs
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Life cycle
of the
blood
fluke
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Adaptive advantages of
cephalization
• Beginnings of cephalization,
increases the effectiveness of a
bilateral animal to find food and
detect enemies
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Mollusca
• Soft bodied animals usually
covered by a shell
• Ventral foot for locomotion
• Mantle covering the visceral
mass
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Mollusca, cont.
• Open circulatory system (except
cephalopods)
• Metanephridia
• Radula
• Ciliated trochophore larva
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Four classes of Phylum
Mollusca
• Polyplacophora
• Gastropoda
• Bivalvia
• Cephalopoda
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Class Polyplacophora
• Shells consist of eight
overlapping plates
–Chitons
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Class Polyplacophora
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Class Gastropoda
• Body undergoes torsion
–Snails
–Slugs
–Relatives
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Class Gastropoda
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Embryonic torsion in a gastropod
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Class Bivalvia
• two-part, dorsally-hinged shell
encloses body
–Aquatic clams
–Scallops
–Oysters
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Class Bivalvia
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Class Cephalopoda
• Active, predatory swimmers
• Tentacles surround the mouth
located in the large head
–Squids
–Octopods
–Nautilus
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Class Cephalopoda
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Annelida
• Segmented worms
–Aquatic worms
–Earthworms
–Leeches
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Annelida, cont.
• Conspicuously long bodies
–Internal and external segmentation
• Large compartmentalized coelom
serves as a hydrostatic skeleton
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Phylum Annelida has three
classes
• Polychaeta
• Oligochaeta
• Hirudinea
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Class Polychaeta
• Marine worms with
–Parapodia for locomotion and gas
exchange
–Setae on the parapodia
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Class Oligochaeta
• Earthworms
–A few short setae per segment
–Body is divided into more than 100
segments separated internally by
septa
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Body plan of an
earthworm
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Class Hirudinea
• Leeches
–No setae
–No appendages
–Parasitic leeches have suckers for
holding onto their host
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Nematoda
• Pseudocoelomates
–Bilateral symmetry
–Three tissue layers
–Complete digestive tract
–Body covered by cuticle
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Parasitic nematodes in humans
• Ascaris
• Hookworms
• Trichina worms
• Pinworms
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
The roundworm Ascaris
(a) Longitudinal section
(b) Cross section
(b)
(a)
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Arthropoda
• Segmented animals with
–Paired, jointed appendages
–Armor-like exoskeleton of chitin
• Molting is necessary for growth
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Arthropoda, cont.
• Open circulatory system
• Dorsal heart that pumps
hemolymph
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Distinguishing characteristics of
phylum Arthropoda, cont.
• Aquatic forms have gills
• Terrestrial forms have either
tracheae or book lungs
• Trilobites are extinct marine
arthropods covered by a hard,
segmented shell
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Subphylum Myriapoda
• Unbranched appendages and a
single pair of antennae
–Class Chilopoda
–Class Diplopoda
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
Dorsal view
CHAPTER 29 The Animal Kingdom: The Protostomes
Trilobite
Copyright © 2005 Brooks/Cole — Thomson Learning
Ventral view
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Subphylum Chelicerata
• Body consists of a cephalothorax
and abdomen, with six pairs of
jointed appendages, four pairs of
which serve as legs
–Merostomes
–Arachnids
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Subphylum Chelicerata, cont.
• First pair of appendages are
chelicerae
• Second pair are pedipalps
• No antennae
• No mandibles
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Subphylum Crustacea
• Lobsters
• Crabs
• Shrimp
• Pillbugs
• Barnacles
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Anatomy
of the
lobster
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Subphylum Crustacea, cont.
• Cephalothorax
• Abdomen
• Five pairs of walking legs
• Two pairs of antennae
• Mandibles
• Maxillae
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Subphylum Hexapoda
• Includes class Insecta
• Branched appendages
• Single pair of antennae
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Subphylum Hexapoda, cont.
• An insect is an articulated,
tracheated hexapod with
–Trachae
–Malpighian tubes
• Body consists of
–Head
–Thorax
–Abdomen
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
Anatomy of
the
grasshopper
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Adaptations contributing to
biological success of insects
• Versatile exoskeleton
• Segmentation
• Specialized jointed appendages
• Ability to fly
• Highly developed sense organs
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 29 The Animal Kingdom: The Protostomes
• Adaptations contributing to
biological success of insects, cont.
• Metamorphosis
• Effective reproductive stragegies
• Effective mechanisms for defense
and offense
• Ability to communicate
Copyright © 2005 Brooks/Cole — Thomson Learning