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Nutritional Mode ,[object Object],[object Object],An Introduction to Animal Diversity Cell Structure and Specialization Animals are multicellular eukaryotes Their cells lack cell walls
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Reproduction and Development ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],Figure 32.2 Zygote Cleavage Eight-cell stage Cleavage Blastula Cross section  of blastula Blastocoel Blastocoel Gastrula Gastrulation Endoderm Ectoderm Blastopore In most animals, cleavage results in the formation of a multicellular stage called a blastula. The blastula of many animals is a hollow ball of cells. 3 The endoderm of the archenteron de- velops into the tissue lining the animal’s digestive tract. 6 The blind pouch formed by gastru- lation, called the archenteron, opens to the outside via the blastopore. 5 Most animals also undergo gastrulation, a rearrangement of the embryo in which one end of the embryo folds inward, expands, and eventually fills the blastocoel, producing layers of embryonic tissues: the ectoderm (outer layer) and the endoderm (inner layer). 4 Only one cleavage stage–the eight-cell embryo–is shown here. 2 The zygote of an animal undergoes a succession of mitotic cell divisions called cleavage. 1
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[object Object],[object Object],[object Object],Figure 32.3 Single cell Stalk
[object Object],Figure 32.4 Colonial protist, an aggregate of identical cells Hollow sphere of unspecialized cells (shown in cross section) Beginning of cell specialization  Infolding  Gastrula-like “protoanimal”  Somatic cells Digestive cavity Reproductive cells
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[object Object],[object Object]
Symmetry ,[object Object],[object Object],Figure 32.7a Radial symmetry.  The parts of a radial animal, such as a sea anemone (phylum Cnidaria), radiate from the center. Any imaginary slice through the central axis divides the animal into mirror images. (a)
[object Object],[object Object],Figure 32.7b Bilateral symmetry.  A bilateral  animal, such as a lobster (phylum Arthropoda), has a left side and a right side. Only one imaginary cut divides the animal into mirror-image halves. (b)
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Tissues ,[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Body Cavities ,[object Object],[object Object]
[object Object],[object Object],Figure 32.8a Coelom Body covering (from ectoderm) Digestive tract (from endoderm) Tissue layer lining coelom and suspending internal organs (from mesoderm) Coelomate.  Coelomates such as annelids have a true coelom, a body cavity completely lined by tissue derived from mesoderm. (a)
[object Object],[object Object],Figure 32.8b Pseudocoelom Muscle layer (from  mesoderm) Body covering (from ectoderm) Digestive tract (from ectoderm) Pseudocoelomate.  Pseudocoelomates such as nematodes have a body cavity only partially lined by tissue derived from mesoderm. (b)
[object Object],[object Object],Figure 32.8c Body covering (from ectoderm) Tissue- filled region (from  mesoderm) Digestive tract (from endoderm) Acoelomate.  Acoelomates such as flatworms lack a body cavity between the digestive tract and outer body wall. (c)
Protostome and Deuterostome Development ,[object Object],[object Object]
Cleavage ,[object Object],[object Object],[object Object],[object Object],Figure 32.9a Protostome development (examples: molluscs, annelids, arthropods) Deuterostome development (examples: echinoderms, chordates) Eight-cell stage Eight-cell stage Spiral and determinate Radial and indeterminate (a) Cleavage.  In general, protostome development begins with spiral, determinate cleavage. Deuterostome development is characterized by radial, indeterminate cleavage.
Coelom Formation ,[object Object],[object Object],[object Object],[object Object],Figure 32.9b Archenteron Blastopore Mesoderm Coelom Blastopore Mesoderm Schizocoelous: solid masses of mesoderm split and form coelom Enterocoelous: folds of archenteron form coelom Coelom (b) Coelom formation.  Coelom formation begins in the gastrula stage. In protostome development, the coelom forms from splits in the mesoderm (schizocoelous development). In deuterostome development, the coelom forms from mesodermal outpocketings of the archenteron (enterocoelous development).
Fate of the Blastopore ,[object Object],[object Object],[object Object],[object Object],Figure 32.9c Anus Anus Mouth Mouth Mouth develops from blastopore Anus develops from blastopore Digestive tube
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[object Object],Figure 32.10 Porifera Cnidaria Ctenophora Phoronida Ectoprocta Brachiopoda Echinodermata Chordata Platyhelminthes Mollusca Annelida Arthropoda Rotifera Nemertea Nematoda “ Radiata ” Deuterostomia Protostomia Bilateria Eumetazoa Metazoa Ancestral colonial flagellate
[object Object],Figure 32.11 Calcarea Silicarea Ctenophora Cnidaria Echinodermata Chordata Brachiopoda Phoronida Ectoprocta Platyhelminthes Nemertea Mollusca Annelida Rotifera Nematoda Arthropoda “ Radiata” “ Porifera” Deuterostomia Lophotrochozoa Ecdysozoa Bilateria Eumetazoa Metazoa Ancestral colonial flagellate
Points of Agreement ,[object Object],[object Object],[object Object]
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Disagreement over the Bilaterians ,[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Figure 32.12
[object Object],[object Object],[object Object],[object Object],Figure 32.13a, b Apical tuft of cilia Mouth Anus (a) An ectoproct, a lophophorate (b) Structure of trochophore larva
Future Directions in Animal Systematics ,[object Object],[object Object]
Invertebrates ,[object Object],[object Object],Ancestral colonial choanoflagellate Eumetazoa Bilateria Deuterostomia Porifera Cnidaria Other bilaterians (including Nematoda, Arthropoda, Mollusca, and Annelida) Echinodermata Chordata Figure 33.2
Sponges ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Figure 33.4 Azure vase sponge  (Callyspongia  plicifera) Osculum Spicules Water flow Flagellum Collar Food particles in mucus Choanocyte Phagocytosis of food particles Amoebocyte Choanocytes. The spongocoel  is lined with feeding cells called  choanocytes. By beating flagella,  the choanocytes create a current that  draws water in through the porocytes. Spongocoel. Water  passing through porocytes  enters a cavity called the  spongocoel. Porocytes. Water enters the epidermis through  channels formed by  porocytes, doughnut-shaped  cells that span the body wall. Epidermis. The outer  layer consists of tightly packed epidermal cells. Mesohyl. The wall of this simple sponge consists of  two layers of cells separated by a gelatinous matrix, the mesohyl (“middle matter”). The movement of the choanocyte  flagella also draws water through its  collar of fingerlike projections. Food  particles are trapped in the mucus  coating the projections, engulfed by  phagocytosis, and either digested or  transferred to amoebocytes. Amoebocyte. Amoebocytes  transport nutrients to other cells of the sponge body and also produce  materials for skeletal fibers (spicules). 5 6 7 4 3 2 1
Cnidarians ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Mouth/anus Tentacle Gastrovascular cavity Gastrodermis Mesoglea Epidermis Tentacle Body stalk Mouth/anus Medusa Polyp Figure 33.5
[object Object],[object Object],[object Object],[object Object],Tentacle “ Trigger” Nematocyst Coiled thread Discharge Of thread Cnidocyte Prey Figure 33.6
[object Object],(a) These colonial polyps are members of  class Hydrozoa. (b) Many species of jellies (class Scyphozoa), including the species pictured here, are  bioluminescent. The largest  scyphozoans have tentacles more than 100 m long  dangling from a bell-shaped  body up to 2 m in diameter. (c) The sea wasp ( Chironex  fleckeri ) is a member of  class Cubozoa. Its poison, which can subdue fish and other large prey, is more  potent than cobra venom. (d) Sea anemones and other members of class Anthozoa exist only as polyps. Figure 33.7a–d
Hydrozoans ,[object Object],[object Object],The zygote develops into a  solid ciliated larva called a planula. 5 The planula eventually settles  and develops into a new polyp. 6 Feeding  polyp Reproductive polyp Medusa bud ASEXUAL REPRODUCTION (BUDDING) Gonad Medusa MEIOSIS FERTILIZATION SEXUAL REPRODUCTION Egg Sperm Developing polyp Portion of a colony of polyps Mature polyp Planula (larva) Key Haploid ( n ) Diploid (2 n ) 1 mm Zygote Figure 33.8 A colony of interconnected polyps (inset, LM) results from asexual reproduction by budding. 1 Some of the colony’s  polyps, equipped with tentacles,  are specialized for feeding. 2 Other polyps, specialized  for reproduction, lack  tentacles and produce tiny  medusae by asexual budding. 3 The medusae  swim off, grow, and  reproduce sexually. 4
Scyphozoans ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
bilateral symmetry ,[object Object],[object Object],[object Object]
Flatworms ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],[object Object],[object Object],Pharynx. The mouth is at the tip of a muscular pharynx that extends from the animal’s ventral side. Digestive juices are spilled onto prey, and the pharynx sucks small pieces of food into the gastrovascular cavity, where digestion continues. Digestion is completed within the cells lining the gastro- vascular cavity, which has three branches, each with fine subbranches that pro- vide an extensive surface area. Undigested wastes are egested through the mouth. Ganglia. Located at the anterior end of the worm, near the main sources of sensory input, is a pair of ganglia, dense clusters of nerve cells. Ventral nerve cords. From the ganglia, a pair of ventral nerve cords runs the length of the body. Gastrovascular cavity Eyespots Figure 33.10
Monogeneans and Trematode ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],These larvae penetrate the skin and blood  vessels of humans  working in irrigated  fields contaminated  with infected human  feces. Asexual reproduction  within a snail results in  another type of motile larva, which escapes from  the snail host. Blood flukes reproduce  sexually in the human host.  The fertilized eggs exit the  host in feces. The eggs develop in  water into ciliated  larvae. These larvae infect snails, the  intermediate hosts. Snail host 1 mm Female Male 5 2 3 4 Figure 33.11 Mature flukes live in the blood vessels of the human  intestine. A female fluke fits into a groove running  the length of the larger male’s body, as shown in  the light micrograph at right. 1
Tapeworm ,[object Object],[object Object],Proglottids with reproductive structures 200 µm Hooks Sucker Scolex Figure 33.12
Rotifers ,[object Object],[object Object],[object Object],[object Object],0.1 mm Figure 33.13
[object Object],[object Object],[object Object],[object Object]
Lophophorates: Ectoprocts, Phoronids, and Brachiopods ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Nemerteans ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Figure 33.15
Molluscs ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Visceral mass Mantle Foot Coelom Intestine Gonads Mantle cavity Anus Gill Nerve cords Esophagus Stomach Shell Radula Mouth Mouth Nephridium. Excretory organs  called nephridia remove metabolic  wastes from the hemolymph. Heart. Most molluscs have an open circulatory  system. The dorsally located heart pumps  circulatory fluid called hemolymph through arteries  into sinuses (body spaces). The organs of the  mollusc are thus continually bathed in hemolymph.  The long digestive tract is  coiled in the visceral mass. Radula. The mouth  region in many  mollusc species  contains a rasp-like  feeding organ  called a radula. This  belt of backward- curved teeth slides  back and forth,  scraping and  scooping like a  backhoe.  The nervous  system consists  of a nerve ring  around the  esophagus, from  which nerve  cords extend. Figure 33.16
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Chitons ,[object Object],[object Object],Figure 33.17
Gastropods ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],A land snail  (a) A sea slug. Nudibranchs, or sea slugs, lost their shell  during their evolution.  (b) Figure 33.18a, b
[object Object],[object Object],Anus Mantle cavity Stomach Intestine Mouth Figure 33.19
Bivalves ,[object Object],[object Object],[object Object],Figure 33.20
[object Object],[object Object],Hinge area Gut Coelom Heart Adductor muscle Anus Excurrent siphon Water flow Incurrent siphon Gill Mantle cavity Foot Palp Mouth Shell Mantle Figure 33.21
Cephalopods ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
` ,[object Object],[object Object],Figure 33.22c (c) Chambered nautiluses are the only living  cephalopods with an external shell.
Annelids ,[object Object],[object Object],[object Object],[object Object]
Oligochaetes ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object]
[object Object],Table 33.23 Mouth Subpharyngeal ganglion Pharynx Esophagus Crop Gizzard Intestine Metanephridium Ventral vessel Nerve cords Nephrostome Intestine Dorsal vessel Longitudinal muscle Circular muscle Epidermis Cuticle Septum (partition between segments) Anus Each segment is surrounded by longitudinal muscle, which in  turn is surrounded by circular muscle. Earthworms coordinate  the contraction of these two sets of muscles to move (see  Figure 49.25). These muscles work against the noncompressible  coelomic fluid, which acts as a hydrostatic skeleton. Coelom. The coelom  of the earthworm is  partitioned by septa. Metanephridium. Each  segment of the worm  contains a pair of  excretory tubes, called  metanephridia, with  ciliated funnels, called  nephrostomes. The  metanephridia remove  wastes from the blood  and coelomic fluid  through exterior pores. Tiny blood vessels are  abundant in the earthworm’s  skin, which functions as its  respiratory organ. The blood  contains oxygen-carrying hemoglobin. Ventral nerve cords with segmental ganglia.  The nerve cords penetrate the septa and run  the length of the animal, as do the digestive  tract and longitudinal blood vessels. The circulatory system, a network of vessels,  is closed. The dorsal and ventral vessels are linked  by segmental pairs of vessels. The dorsal vessel  and five pairs of vessels that circle the esophagus  of an earthworm are muscular and pump blood  through the circulatory system. Cerebral ganglia. The  earthworm nervous system  features a brain-like pair of  cerebral ganglia above and  in front of the pharynx. A ring  of nerves around the pharynx  connects to a subpharyngeal  ganglion, from which a fused  pair of nerve cords runs  posteriorly. Chaetae. Each segment  has four pairs of  chaetae, bristles that  provide traction for  burrowing.  Many of the internal  structures are repeated  within each segment of  the earthworm.  Giant Australian earthworm Clitellum
Nematodes ,[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],25 µm Figure 33.26
Arthropods ,[object Object],[object Object],[object Object],[object Object]
General Characteristics of Arthropods ,[object Object],[object Object],Antennae (sensory reception) Head Thorax Swimming appendages Walking legs Mouthparts (feeding) Pincer (defense) Abdomen Cephalothorax Figure 33.29 Figure 33.28
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Cheliceriforms ,[object Object],[object Object],[object Object],[object Object],[object Object],Figure 33.30
[object Object],[object Object],Scorpions have pedipalps that are pincers  specialized for defense and the capture of  food. The tip of the tail bears a poisonous  stinger. (a) Dust mites are ubiquitous scavengers in  human dwellings but are harmless except  to those people who are allergic to them  (colorized SEM). (b) Web-building spiders are generally  most active during the daytime. (c) 50 µm Figure 33.31a–c
[object Object],[object Object],Digestive gland Intestine Heart Stomach Brain Eyes Poison gland Pedipalp Chelicera Book lung Sperm receptacle Gonopore (exit for eggs) Silk gland Spinnerets Anus Ovary Figure 33.32
Myriapods ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Figure 33.33 Figure 33.34
Insects ,[object Object],[object Object],[object Object]
[object Object],[object Object],Compound eye Antennae Anus Vagina Ovary Dorsal artery Crop Abdomen Thorax Head The insect body has three regions: head,  thorax, and abdomen. The segmentation  of the thorax and abdomen are obvious,  but the segments that form the head are fused.  Heart. The  insect heart  drives hemolymph  through an  open circulatory  system. Cerebral ganglion. The two nerve  cords meet in the head, where the  ganglia of several anterior segments  are fused into a cerebral ganglion  (brain). The antennae, eyes, and  other sense organs are concentrated  on the head. Tracheal tubes. Gas exchange in insects is  accomplished by a tracheal system of branched,  chitin-lined tubes that infiltrate the body and  carry oxygen directly to cells. The tracheal  system opens to the outside of the body  through spiracles, pores that can control air  flow and water loss by opening or closing. Nerve cords. The insect  nervous system  consists of a pair of  ventral nerve cords  with several  segmental ganglia. Insect mouthparts are formed from  several pairs of modified appendages.  The mouthparts include mandibles,  which grasshoppers use for chewing.  In other insects, mouthparts are  specialized for lapping, piercing, or  sucking. Malpighian tubules.  Metabolic wastes are removed from the  hemolymph by excretory  organs called Malpighian  tubules, which are out- pocketings of the  digestive tract. Figure 33.35
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[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Larva (caterpillar) (a) (b) Pupa (c) Pupa (d) Emerging adult (e) Adult Figure 33.6a–e
[object Object],ORDER Blattodea  4,000 Cockroaches have a dorsoventrally flattened body, with legs  modified for rapid running. Forewings, when present, are leathery, whereas hind wings are fanlike. Fewer than 40 cock- roach species live in houses; the rest exploit habitats ranging  from tropical forest floors to caves and deserts. Beetles comprise the most species-rich order of insects. They  have two pairs of wings, one of which is thick and leathery, the other membranous. They have an armored exoskeleton and mouthparts adapted for biting and chewing. Beetles undergo complete metamorphosis. Earwigs are generally nocturnal scavengers. While some  species are wingless, others have two pairs of wings, one of  which is thick and leathery, the other membranous. Earwigs have biting mouthparts and large posterior pincers. They un- dergo incomplete metamorphosis. Dipterans have one pair of wings; the second pair has become  modified into balancing organs called halteres. Their head is large and mobile; their mouthparts are adapted for sucking, piercing, or lapping. Dipterans undergo complete metamorpho- sis. Flies and mosquitoes are among the best-known dipterans,  which live as scavengers, predators, and parasites. Hemipterans are so-called “true bugs,” including bed bugs,  assassin bugs, and chinch bugs. (Insects in other orders are sometimes erroneously called bugs.) Hemipterans have two  pairs of wings, one pair partly leathery, the other membranous. They have piercing or sucking mouthparts and undergo incomplete metamorphosis. Ants, bees, and wasps are generally highly social insects. They have two pairs of membranous wings, a mobile head, and  chewing or sucking mouthparts. The females of many species  have a posterior stinging organ. Hymenopterans undergo com- plete metamorphosis. Termites are widespread social insects that produce enormous  colonies. It has been estimated that there are 700 kg of termites for every person on Earth! Some termites have two pairs of membranous wings, while others are wingless. They  feed on wood with the aid of microbial symbionts carried in  specialized chambers in their hindgut. Coleoptera  350,000  Dermaptera 1,200 Diptera 151,000 Hemiptera 85,000 Hymenoptera 125,000 Isoptera 2,000 APPROXIMATE NUMBER OF SPECIES MAIN CHARACTERISTICS EXAMPLES German cockroach Japanese beetle Earwig Horsefly Leaf- Footed bug Cicada-killer wasp Termite Figure 33.37 Lepidoptera 120,000 Butterflies and moths are among the best-known insects. They  have two pairs of wings covered with tiny scales. To feed, they uncoil a long proboscis. Most feed on nectar, but some species  feed on other substances, including animal blood or tears. Odonata 5,000 Dragonflies and damselflies have two pairs of large, membran- ous wings. They have an elongated abdomen, large, compound  eyes, and chewing mouthparts. They undergo incomplete meta- morphosis and are active predators. Orthoptera 13,000 Grasshoppers, crickets, and their relatives are mostly herbi- vorous. They have large hind legs adapted for jumping, two pairs of wings (one leathery, one membranous), and biting or  chewing mouthparts. Males commonly make courtship sounds  by rubbing together body parts, such as a ridge on their hind  leg. Orthopterans undergo incomplete metamorphosis. Phasmida 2,600 Stick insects and leaf insects are exquisite mimics of plants. The  eggs of some species even mimic seeds of the plants on which the  Insects live. Their body is cylindrical or flattened dorsoventrally.  They lack forewings but have fanlike hind wings. Their  mouthparts are adapted for biting or chewing. Phthiraptera 2,400 Commonly called sucking lice, these insects spend their entire  life as an ectoparasite feeding on the hair or feathers of a single host. Their legs, equipped with clawlike tarsi, are adapted for clinging to their hosts. They lack wings and have reduced eyes. Sucking lice undergo incomplete metamorphosis. Siphonaptera 2,400 Fleas are bloodsucking ectoparasites on birds and mammals.  Their body is wingless and laterally compressed. Their legs are  modified for clinging to their hosts and for long-distance  jumping. They undergo complete metamorphosis. Thysanura 450 Silverfish are small, wingless insects with a flattened body and  reduced eyes. They live in leaf litter or under bark. They can also  infest buildings, where they can become pests. Trichoptera 7,100 The larvae of caddisflies live in streams, where they make houses  from sand grains, wood fragments, or other material held to- gether by silk. Adults have two pairs of hairy wings and chewing or lapping mouthparts. They undergo complete metamorphosis. Swallowtail butterfly Dragonfly Katydid Stick insect Human Body louse Flea Silverfish Caddisfly ORDER APPROXIMATE NUMBER OF SPECIES MAIN CHARACTERISTICS EXAMPLE Figure 33.37
Crustaceans ,[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],[object Object],[object Object],Ghost crabs (genus  Ocypode ) live on sandy ocean  beaches worldwide. Primarily nocturnal, they take  shelter in burrows during the day. (a) Figure 33.38a Planktonic crustaceans  known as krill are  consumed in vast  quantities by whales. (b) Figure 33.38b
[object Object],[object Object],The jointed appendages  projecting from the shells of these barnacles capture  organisms and organic  particles suspended in the water. (c) Figure 33.38c
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Echinoderms ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Stomach Anus Ring canal Gonads Ampulla Podium Radial nerve Tube feet Spine Gills A short digestive tract runs from the  mouth on the bottom of the central  disk to the anus on top of the disk. The surface of a sea star is  covered by spines that help  defend against predators, as  well as by small gills that  provide gas exchange. Madreporite. Water can flow  in or out of the water vascular  system into the surrounding  water through the madreporite. Branching from each radial canal are hundreds of hollow, muscular tube  feet filled with fluid. Each tube foot consists of a bulb-like ampulla and  suckered podium (foot portion). When the ampulla squeezes, it forces  water into the podium and makes it expand. The podium then  contacts the substrate. When the muscles in the wall of the podium contract, they force water back into the ampulla, making the podium  shorten and bend. Radial canal. The water vascular  system consists of a ring canal in the  central disk and five radial canals,  each running in a groove down the  entire length of an arm. Digestive glands secrete  digestive juices and aid in  the absorption and storage  of nutrients. Central disk. The central  disk has a nerve ring and  nerve cords radiating from  the ring into the arms. Figure 33.39
Sea Stars ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],(a) A sea star (class Asteroidea) Figure 33.40a (b) A brittle star (class Ophiuroidea) Figure 33.40b
Sea Urchins and Sand Dollars ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],(c) A sea urchin (class Echinoidea) Figure 33.40c
Sea Cucumbers ,[object Object],[object Object],[object Object],[object Object],[object Object],(e) A sea cucumber (class Holothuroidea) Figure 33.40e (f) A sea daisy (class Concentricycloidea) Figure 33.40f
Chordates ,[object Object],[object Object],[object Object],[object Object]
Vertebrates ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Derived Characters of Chordates ,[object Object],[object Object],Muscle segments Brain Mouth Anus Dorsal, hollow nerve cord Notochord Muscular, post-anal tail Pharyngeal slits or clefts Figure 34.3
Notochord ,[object Object],[object Object],[object Object],[object Object],[object Object]
Dorsal, Hollow Nerve Cord ,[object Object],[object Object],[object Object]
Pharyngeal Slits or Clefts ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Muscular, Post-Anal Tail ,[object Object],[object Object],[object Object],[object Object]
Tunicates ,[object Object],[object Object],[object Object],[object Object],[object Object]
Lancelets ,[object Object],[object Object],[object Object],[object Object],Tentacle Mouth Pharyngeal slits Atrium Digestive tract Atriopore Segmental muscles Anus Notochord Dorsal, hollow nerve cord Tail  2 cm Figure 34.5
Hagfishes ,[object Object],[object Object],[object Object],[object Object],[object Object],Figure 34.9 Slime glands
Derived Characters of Vertebrates ,[object Object],[object Object],[object Object],[object Object]
Lampreys ,[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Chondrichthyans (Sharks, Rays, and Their Relatives) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Ray-Finned Fishes and Lobe-Fins ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Nostril Brain Spinal cord Swim bladder Dorsal fin Adipose fin (characteristic of trout) Caudal  fin Cut edge of  operculum Gills Heart Liver Kidney Stomach Intestine Gonad Anus Urinary  bladder Lateral  line Anal fin Pelvic fin Figure 34.16
Ray-Finned Fishes ,[object Object],[object Object],(a)  Yellowfin tuna  (Thunnus  albacares),  a fast-swimming,  schooling fish that is an important  commercial fish worldwide (b)  Clownfish  (Amphiprion  ocellaris),  a mutualistic  symbiont of sea anemones (c)  Sea horse  (Hippocampus  ramulosus),  unusual in  the animal kingdom in that  the male carries the young  during their embryonic  development (d)  Fine-spotted moray eel  (Gymnothorax dovii),  a  predator that ambushes  prey from crevices in its  coral reef habitat Figure 34.17a–d
[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],[object Object],Figure 34.18
Derived Characters of Tetrapods ,[object Object],[object Object],[object Object],[object Object],[object Object],Tetrapod limb skeleton Bones supporting gills Figure 34.19
Amphibians ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Figure 34.22a–c (a)  The male grasps the female, stimulating her to  release eggs. The eggs are laid and fertilized in  water. They have a jelly coat but lack a shell and  would desiccate in air. (b)  The tadpole is  an aquatic  herbivore with a fishlike tail and  internal gills. (c)  During metamorphosis, the  gills and tail are resorbed, and walking legs develop.
[object Object],[object Object],[object Object]
[object Object],[object Object],Figure 34.24 Shell Albumen Yolk (nutrients) Amniotic cavity with amniotic fluid Embryo Yolk sac.  The yolk sac contains the  yolk, a stockpile of nutrients. Blood  vessels in the yolk sac membrane transport  nutrients from the yolk into the embryo.  Other nutrients are stored in the albumen (“egg white”). Allantois.  The allantois is a disposal sac for certain metabolic wastes pro- duced by the embryo. The membrane of the allantois also functions with the chorion as a respiratory organ. Amnion.  The amnion protects the embryo in a fluid-filled  cavity that cushions against mechanical shock. Chorion.  The chorion and the membrane of the  allantois exchange gases between the embryo  and the air. Oxygen and carbon dioxide diffuse  freely across the shell. Extraembryonic membranes
[object Object],[object Object]
Reptiles ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],[object Object],Figure 34.26
Lepidosaurs ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Figure 34.27a (a) Tuatara  (Sphenodon punctatus) Figure 34.27b (b) Australian thorny devil  lizard  (Moloch horridus)
Turtles ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Alligators and Crocodiles ,[object Object],[object Object],Figure 34.27e (e) American alligator  (Alligator mississipiensis)
Birds ,[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Figure 34.28a–c (a) wing (b) Bone structure Finger 1 (c) Feather structure Shaft Barb Barbule Hook Vane Shaft Forearm Wrist Palm Finger 3 Finger 2
[object Object],[object Object],[object Object],[object Object],Figure 34.29 Toothed beak Airfoil wing with  contour feathers Long tail with  many vertebrae Wing claw
Living Birds ,[object Object],[object Object],Figure 34.30a (a) Emu.  This ratite lives in Australia.
[object Object],[object Object],Figure 34.31 Grasping bird  (such as a  woodpecker) Perching bird  (such as a  cardinal) Raptor (such as a  bald eagle) Swimming bird (such as a duck)
Mammals ,[object Object],[object Object],[object Object]
Derived Characters of Mammals ,[object Object],[object Object],[object Object],[object Object],[object Object]
Monotremes ,[object Object],[object Object],Figure 34.33
Marsupials ,[object Object],[object Object],[object Object],[object Object],Figure 34.34a (a) A young brushtail possum.  The young of  marsupials are born very early in their  development. They finish their growth  while nursing from a nipple (in their  mother’s pouch in most species).
[object Object],[object Object],Figure 34.34b (b) Long-nosed bandicoot.  Most bandicoots  are diggers and burrowers that eat mainly  insects but also some small vertebrates and plant material. Their rear-opening pouch helps  protect the young from dirt as the mother digs.  Other marsupials, such as kangaroos, have a  pouch that opens to the front.
[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Figure 34.35 Marsupial mammals Eutherian mammals Plantigale Marsupial mole Sugar glider Wombat Tasmanian devil Kangaroo Deer mouse Mole  Woodchuck Flying squirrel Wolverine Patagonian cavy
[object Object],Figure 34.36  ORDERS AND EXAMPLES MAIN  CHARACTERISTICS Monotremata   Platypuses,  echidnas Proboscidea   Elephants Sirenia Manatees, dugongs Cetartiodactyla Artiodactyls Sheep, pigs  cattle, deer, giraffes  Lagomorpha  Rabbits,  hares, picas Carnivora   Dogs, wolves, bears, cats,  weasels, otters, seals, walruses Xenarthra   Sloths,  anteaters, armadillos Cetaceans Whales, dolphins, porpoises Echidna African elephant Manatee Tamandua Jackrabbit Coyote Bighorn sheep Pacific white- sided porpoise Lay eggs; no nipples; young  suck milk from fur of mother Long, muscular trunk; thick,  loose skin; upper  incisors elongated  as tusks Aquatic; finlike forelimbs and  no hind limbs;  herbivorous Reduced teeth or no teeth; herbivorous (sloths) or carnivorous  (anteaters,  armadillos) Chisel-like incisors;  hind legs longer than  forelegs and adapted  for running and  jumping Sharp, pointed canine teeth and molars for  shearing; carnivorous Hooves with an  even number  of toes on each  foot; herbivorous Aquatic; streamlined body; paddle-like  forelimbs and no  hind limbs; thick layer of insulating  blubber; carnivorous Diet consists mainly  of insects and other  small invertebrates Adapted for flight; broad  skinfold that extends  from elongated fingers  to body and legs;  carnivorous or  herbivorous Hooves with an  odd number of toes on each foot;  herbivorous Opposable thumbs;  forward-facing eyes;  well-developed  cerebral cortex;  omnivorous Chisel-like, continuously  growing incisors worn  down by gnawing; herbivorous Short legs; stumpy tail;  herbivorous; complex,  multichambered stomach Teeth consisting of  many thin tubes  cemented together;  eats ants and termites Embryo completes  development in  pouch on mother ORDERS AND EXAMPLES MAIN  CHARACTERISTICS Marsupialia Kangaroos, opossums, koalas Tubulidentata Aardvark Hyracoidea Hyraxes Chiroptera Bats Primates Lemurs, monkeys, apes, humans Perissodactyla Horses, zebras, tapirs, rhinoceroses Rodentia Squirrels, beavers, rats,  porcupines, mice   Eulipotyphla “ Core insecti- vores”: some  moles, some  shrews Star-nosed  mole Frog-eating bat Indian rhinoceros Golden lion  tamarin Red squirrel Rock hyrax Aardvark Koala
Primates ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],Figure 34.39a, b (a)  New World monkeys, such as spider  monkeys (shown here), squirrel monkeys, and  capuchins, have a prehensile tail and nostrils  that open to the sides. (b)   Old World monkeys lack a prehensile tail, and their nostrils  open downward. This group includes macaques (shown here),  mandrills, baboons, and rhesus monkeys.
[object Object],[object Object],Figure 34.40a–e (a)  Gibbons, such as this Muller's gibbon, are  found only in southeastern Asia. Their very  long arms and fingers are adaptations for  brachiation. (b)  Orangutans are shy, solitary apes that live in the rain  forests of Sumatra and Borneo. They  spend most of  their time in trees; note the foot adapted for grasping  and the opposable thumb. (c)  Gorillas are the largest apes: some  males are almost 2 m tall and weigh  about 200 kg. Found only in Africa, these  herbivores usually live in groups of up to  about 20 individuals. (d)  Chimpanzees live in tropical Africa. They  feed and sleep in trees but also spend a  great deal of time on the ground. Chimpanzees  are intelligent, communicative, and social. (e)  Bonobos are closely  related to chimpanzees  but are smaller. They  survive today only in the  African nation of Congo.
[object Object],[object Object],[object Object]
Derived Characters of Hominids ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
The Earliest Humans ,[object Object],[object Object]
[object Object],Figure 34.41 Homo sapiens Homo neanderthalensis Homo ergaster ? Homo erectus Homo habilis Homo rudolfensis Paranthropus robustus Paranthropus boisei Australopithecus garhi Australopithecus africanus Australopithecus afarensis Kenyanthropus platyops Australopithecus anamensis Ardipithecus ramidus Orrorin tugenensis Sahelanthropus tchadensis 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Millions of years ago
Early  Homo ,[object Object],[object Object],[object Object],[object Object]
[object Object],[object Object],[object Object],Figure 34.43
[object Object],[object Object],[object Object]
Neanderthals ,[object Object],[object Object],[object Object],[object Object]
Homo sapiens ,[object Object],[object Object],[object Object],[object Object],Figure 34.44
[object Object],[object Object],Figure 34.45

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  • 51. Visceral mass Mantle Foot Coelom Intestine Gonads Mantle cavity Anus Gill Nerve cords Esophagus Stomach Shell Radula Mouth Mouth Nephridium. Excretory organs called nephridia remove metabolic wastes from the hemolymph. Heart. Most molluscs have an open circulatory system. The dorsally located heart pumps circulatory fluid called hemolymph through arteries into sinuses (body spaces). The organs of the mollusc are thus continually bathed in hemolymph. The long digestive tract is coiled in the visceral mass. Radula. The mouth region in many mollusc species contains a rasp-like feeding organ called a radula. This belt of backward- curved teeth slides back and forth, scraping and scooping like a backhoe. The nervous system consists of a nerve ring around the esophagus, from which nerve cords extend. Figure 33.16
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