SurveyAnimal Kingdom I

1
Survey-Animal Kingdom I

• Porifera ? Cnidaria ? Platyhelminthes ?
  Nematoda ?Annelida

2
Review of Animal Development
3
Phylum Porifera

• Belongs to Parazoa (beside the animals)
• Evolved from colonial protozoans
• Evolutionary dead end
• Most primitive animals

4
Sponges come in many colors
5
Phylum Porifera

• General characteristics
• pore-bearing animals
• sessile
• most are marine
• asymmetrical
• diploblastic
• ? 5,000 species

6
Porifera General Construction

• one hole sac
• central cavity spongiocoel
• water enters through ostium
• water exits through osculum
• filter feeders algae, bacteria, organic debris

7
Anatomy of a Sponge
8
Anatomy of a Sponge
9
Porifera Anatomy

• choanocytes or collar cells- create water
  currents for circulation feeding
• spicule-skeletal element for support
• amoebocyte-transport of nutrients from
  choanocytes to non-feeding cells
• mesenchyme-gelatinous protein colloid not a
  cellular layer

10
Porifera Reproduction

• Asexual budding, regeneration, gemmules
• Sexual- sperm and ova arise from ameobocytes or
  choanocytes
• Sponges are monoecious (one house) which is a
  reference to both sperm and ova production by a
  single organism

11
Development of a Sponge
?
?
?
?

• 1) Zygote
• 2) Embryo
• 3) Breaks open everts
• 4) Larvum (amphiblastula)
• 5) Invaginates to form sessile adult

12
Classification of sponges

• Based on canal system
• Ascon simplest 2 layer sac
• Leucosolenia
• Sycon surface is folded to increase surface
  area Grantia
• Leucon most advanced successful permits
  maximum surface size surface deeply folded to
  form systems of canals commercial sponges

13
Classification of sponges

• Based on spicule type
• Calcium spicules CaCO3 (calcium carbonate)
  chalk sponges
• Silicon spicules Si3O2 glass sponges
• Spongin spicules organic or horny natural
  commercial sponges

14
Phylum Cnidaria

• Subkingdom Eumetazoa
• organ, organ system level of development
• Grade Radiata radial symmetry
• Coelenterata hollow gut or cavity
• gastrovascular cavity
• Name derived from cnidocytes
• specialized stinging cells around mouth
  tentacles

15
Close-up of a Cnidocyte
16
Two basic structural forms

• Polyp
• 1) sessile
• 2) asexual budding
• 3) sexual gamete production
• Medusa
• 1) motile
• 2) sexual only
• One or both may occur in a given life cycle

17
Anatomy of a Cnidarian
18
(No Transcript)
19
General Construction

• 3 layer but Diploblastic
• 1) epidermis- (ectoderm)
• epidermal cells
• cnidocytes
• longitudinal muscles cells
• gland cells
• nerve cells connected to sensory receptor
  cells nerve net

20
General Construction

• 2) mesoglea
• middle glue
• gelatinous colloid layer/ not a true
  cellular layer cells found here originate in
  other layers

21
General Construction

• 3) gastrodermis
• lines gastrovascular cavity
• circular muscle
• flagellated nutritive cells
• gland cells -secrete digestive enzymes into
  cavity. Food is partly digested extracellularly.
  Digestion is completed in the nutritive cells.

22
Obelia Life Cycle
23
Obelia Life Cycle
24
Obelia Life Cycle
z
25
Obelia Life Cycle
26
Cnidarian Life Cycle

• Many exhibit a life cycle which is superficially
  plant-like because it alternates between the two
  body forms polyp and medusa.
• Cnidarians exhibit the Diplontic Life Cycle as do
  all animals (only the gametes are 1N)

27
Obelia Life Cycle

• Cnidaria life cycle allows for
• 1) rapid asexual reproduction by polyp
• 2) dispersal genetic recombination by medusa
• 3) habitat selection by planula larvum

28
Classification of Cnidaria

• See pictures in Campbell, 5th ED, Chapter 33,
  page 602
• Class Hydrozoa
• polyp is dominant
• colonial polyps w/high degree of specialization
• Hydra polyp only
• Obelia both forms
• Physalia both forms
• Gonionemus both forms

29
Hydrozoan polyps
30
Classification of Cnidaria

• Class Scyphozoa
• medusa is dominant
• jellies
• Aurelia true jelly fish

31
JELLY MEDUSA
32
Lion Mane Jelly
33
Purple-stripped Jelly
34
Classification of Cnidaria

• Class Anthozoa
• all marine
• no medusa
• feed on mollusks, crustaceans, small fish
• Metridium sea anemones
• Corals

35
Anthozoan Sea Anemone
36
(No Transcript)
37
Coral polyps
38
(No Transcript)
39

• THIS ENDS
  THE PHYLUM CNIDARIA
  AND BEGINS THE
  PHYLUM PLATYHELMINTHES

40
(No Transcript)
41
Grade Bilaterata

• Triploblastic
• All members exhibit bilateral symmetry at some
  point either ancestral forms, larval form, or
  adult form

42
Subgrade Acoelomata

• no body cavity
• solid mesoderm
• no respiratory tract since no cell is more than a
  few mm away from surface
• digestive cavity is branched carrying food to
  all regions

43
Phylum Platyhelminthes

• General characteristics
• triploblastic
• flattened dorsoventrally
• exhibit cephalization anterior posterior
• freshwater, marine, terrestrial
• both free living and parasitic
• incomplete digestive tract mouth anus

44
General construction
epidermis
mesoderm
incomplete digestive tract
gastrodermis
platy flat helminthes worm
45
Classification

• Class Turbellaria
• Class Trematoda ( Monogenea)
• Class Cestoidea (formerly Cestoda)

46
Classification

• Class Turbellaria Planaria
• exhibit regeneration
• carnivorous (extensible pharynx)
• free-living, nocturnal
• fresh water
• monoecious
• locomote via ventral cilia and gland cells
  (slime)
• largest to locomote with cilia

47
A Planarian
48
Classification

• Class Trematoda ( Monogenea)
• Fasciola hepatica- sheep liver fluke
• Clororchis sinensis human liver fluke
• Schistosoma blood flukes that inhabit veins of
  urinary tract
• all are parasitic
• resemble planarians in structure highly
  specialized existence
• special adhesive organs suckers
• complicated life cycles
• infections can occur from poorly cooked fish
  shellfish, and unclean water or skin

49
Fluke Life Cycle
50
Classification

• Class Cestoidea (formerly Cestoda)
• Taenia (beef tapeworm)
• highly specialized internal parasite
• aberrant (atypical) group
• show pseudometamerism each tapeworm is closer
  to being a colony of individuals rather than one
  segmented organism

51
Classification (figure 33.11 page 606)

• Taenia pisiformis
• scolex (head) with hooks and suckers
• neck (immature proglottids)
• mature proglottids (sexually reproductive)
• ripe or gravid proglottids (contain zygotes)
• production of new proglottids is strobilization

52
Tapeworm 1) scolex 2) immature proglottids 3)
mature proglottids 4) gravid proglottids
53
Grade Bilaterata Subgrade Pseudocoelomata Phylu
m Nematoda

• General characteristics
• unsegmented roundworms
• triploblastic
• grossly polyphyletic phylum (8 phyla)
• complete digestive tract
• fluid-filled pseudocoel
• longitudinal muscles only produce a whipping
  motion

54
Phylum Nematoda

• General characteristics
• worldwide distribution cosmopolitan
• terrestrial aquatic
• 712,000 species
• free-living parasitic
• varied nutrition parasitic, carnivorous,
  herbivorous, saprophytic

55
Phylum Nematoda

• A spade full of garden soil contains about 1
  million nematodes.

56
Phylum Nematoda

• epidermis w/ cuticle

• mesoderm

• digestive tract

• gastrodermis

• fluid-filled pseudocoel

l.s. of a typical nematode
57
Nematoda
58
Phylum Nematoda

• Ascaris lumbroides
• 200,000 eggs per day
• parasitic intestinal roundworm
• ova are ingested due to poor sanitation
• dioecious
• cuticle noncellular secreted by epidermis
  impermeable to toxic compounds digestive
  enzymes
• sexually dimorphic

59
Phylum Nematoda

• Enterobius vermicularis
• pin worm (anal worm)
• female worms migrate from the colon to anal area
  at night to lay their eggs
• nervousness, scratching, reinfection

60
Phylum Nematoda

• Necator americanus
• hook worm
• male has hook-shaped body w/cutting plates on
  mouth that cut through the mucosa of the
  intestine
• secrete an anticoaggulant to prevent clotting
• larvum can burrow through soles of feet

61
Phylum Nematoda

• Trichinella spiralis
• Trichina worm
• causes trichinosis
• Eating poorly cooked meat
• Larva become encapsulated in skeletal muscle
  (also in tongue) wherever there is a rich blood
  supply

62
Parasitic Nematode Trichinella
63
Phylum Nematoda

• Loa loa
• eye worm
• Vector mango fly
• Wanders in sub dermal connective tissue (eyes,
  tongue, scrotum)
• Africa

64
Phylum Nematoda

• Wucheria bancrofti
• Filarial worm
• Mosquito vector
• Larval stages in human blood
• Mosquito picks up microfilaria in taking blood
  meal then larvae migrate to thoracic muscles of
  mosquito, grow and migrate to mouth parts
• Mosquito bites human, microfilariae migrate to
  lymphatic system, mature causing blockage
• Elephantiasis

65
Phylum Rotifera

• General characteristics
• wheel animals
  (cilia around mouth resembles a wheel)
• freshwater
• dieocious
• some exhibit parthenogenesis
• size of protozoan but multicellular

66
Phylum Rotifera

• Unique characteristic
• exhibit cell constancy each
  species composed of members possessing exactly
  the same number of cells cell division ceases
  with embryonic development no growth or
  repair

67
Rofiter
68
Subgrade Coelomata Phylum Annelida

• General characteristics
• Segmented worms
• True coelom
• More specialized systems
• Show metamerism true segmentation
  (characteristic of higher animals)
• Organs are paired in segments

69
Subgrade Coelomata Phylum Annelida

• General characteristics
• segmented arrangements of circulatory, excretory,
  nervous, muscular, and reproductive systems
• fluid-filled coelom hydrostatic skeleton

70
Phylum Annelida

• General characteristics
• triploblastic
• ventral nerve cord
• complete digestive tract
• worldwide distribution (cosmopolitan)
• trochophore larvum very similar to mollusk and
  flatworm larvum on this basis, annelids are
  thought to have evolved from a common flatworm
  type ancestor

71
Phylum Annelida

• General Body Plan

• ectoderm

• mesoderm

• endoderm

• coelom

• septum

one metamere
l.s. segmented worm
72
Phylum Annelida Classes

• Oligochaeta (oligo few chaeta bristles)
• earthworms
• Polychaeta (poly many chaeta bristles)
• sandworms (Neries)
• Hirudinea
• leeches

73
Phylum Annelida Class Oligochaeta

• Darwin estimated that 1 acre of farmland
  possessed about 50,000 earthworms which produce
  about 15-18 tons of castings per year

74
Phylum Annelida Class Oligochaeta

• General characteristics
• few setae per segment
• term earthworm is academically incorrect
  because aquatic parasitic forms are included
• most are monoecious, cross-fertilization
• most highly organized animals to have
  regeneration
• clitellum (secretes cocoon)

75
Lumbricus
76
Anatomy of an Annelid
77
Phylum Annelida Class Polychaeta

• General Characteristics
• have numerous setae at ends of parapodia
• parapodia fleshy segmented appendages for
  locomotion breathing
• Neries sandworm
• tube worms

78
Polychaeta Neries
79
Polychaeta Christmas Tree Worm
80
Phylum Annelida Class Hirudinea

• General Characteristics
• mostly fluid feeders
• fresh marine
• possess clitellum apparent only during
  reproduction
• have annelid characteristics but lack setae
• true bloodsuckers have cutting plates for cutting
  through tissue of the host organism
• Hirudo medicinalis medicinal leech
• usually attaches by posterior sucker until
  suitable spot is found for attachment of anterior
  sucker
• salivary glands secrete anticoagulant called
  hirudin that prevents clotting

81
Hirudinea leech
82
Phylum Annelida Class Hirudinea

• Morris Matinee Must See
• ?
• Katherin Hepburn Humphrey Bogart
• African Queen