Invertebrates Survey Lab

1
Invertebrates Survey Lab

• Spring 08

2
Characteristics of ANIMALS

• Representatives of the animal kingdom display a
  wide diversity in appearance. Regardless, they
  do share certain characteristics.
• All animals are heterotrophic, they are all
  multicellular, and their cells are eukaryotic and
  lack cell walls.
• The animal kingdom is divided into several phyla
  (categories). Each phylum contains animals which
  demonstrate common traits. The traits allow for
  a classification system that shows progressive
  change in the phyla from simple to more complex
  life forms.
• In this lab, you will
• examine the anatomy of several invertebrate
  animals
• note the major phylum traits of these
  representative animals
• compare traits of each phylum to the other phyla
  represented

3
Key Terms to Know
4
Key Terms to Know
5
Key Terms to Know
A tube within a tube
6
Key Terms to Know Early Development
Protostomes are organisms that develop a mouth
first and then an anus. Most invertebrates
are protostomes.
Deuterostomes are organisms that develop an anus
first and then mouth. Echinoderms and all
vertebrates are deuterostomes.
7
Key Terms to Know Early Development
During early development, the cells of most
animal embryos separate in three layers called
germ layers
ENDODERM the innermost germ layer develops
into the lining of the digestive tract and much
of the respiratory system MESODERM the middle
germ layer develops into muscles and much of the
circulatory, reproductive, and excretory
system ECTODERM the outermost germ layer
develops into the sense organs, nerves, and outer
layer of the skin
8
Key Concept to Know
9
Phylum Porifera ? Sponges
10
Key Characteristics

• Sponges are multicellular, but do
• not have any tissues
• Sponges are filter feeders that sift microscopic
  food
• particles from the
• water
• Sponges are asymmetrical they have no front or
  back end
• No Cephalization

• Early development ?Protostome
• Habitat ? Water
• Segmentation ? None
• Germ Layers ?None
• Movement ? Sessile, meaning no movement
• No Coelom

11
Ecology of Sponges

• Sponges play an important part in the ecology and
  survival of numerous aquatic organisms
• They usually live attached to the sea floor
• They form mutually beneficial relationships with
  bacteria, algae, and plantlike protists
• They provide a habitat for snails, sea stars, sea
  cucumbers, and shrimp

12
(No Transcript)
13
Phylum Cnidaria ? Jellyfish, Sea anemones, corals
14
Key Characteristics

• Radial Symmetry
• Carnivorous
• No Cephalization
• No Coelom
• Soft/Sac-like Body Plan 2 way digestion (only
  one opening)
• They eat and excrete through the same hole!
• No Segmentation

• 2 Germ Layers
• Ectoderm
• Endoderm
• They dont have a mesoderm layer
• Movement
• Polyps are sessile
• Medusas are free swimming
• Early Development
• Protostome Nerve Net

15

• Cnidarians are radially symmetrical
• They typically have a life cycle that includes
  two different-looking stages a polyp and a
  medusa
• A polyp is a cylindrical body with arm-like
  tentacles
• In a polyp, the mouth points upward
• Polyps are usually sessile (do not move)
• A medusa has a motile, bell-shaped body with the
  mouth on the bottom

16
Cnidarian Activity

• Cnidarians are soft-bodied, carnivorous animals
  that have stinging tentacles arranged in circles
  around their mouths
• They are the simplest animals to have body
  symmetry and specialized tissues
• Cnidocytes are stinging cells that are located
  along their tentacles
• A nematocyst is a poison- filled, stinging
  structure that contains a tiny coiled dart used
  to paralyze and kill prey

• After paralyzing its prey, a cnidarian pulls the
  prey through its mouth into its gastrovascular
  cavity
• Nutrients are then transported through the body
  by diffusion
• Cnidarians gather information from their
  environment using specialized sensory cells
• Most cnidarians reproduce both sexually and
  asexually
• Most sexual reproduction takes place with
  external fertilization (outside the females
  body)

17
Phylum Platyhelminthes ? Flatworms
18
Key Characteristics

• Three germ layers ectoderm, mesoderm, endoderm
• Bilateral symmetry
• Cephalization is present
• Acoelomates - No coelom
• Use diffusion to transport materials through body

• No segmentation
• Movement w/ muscles or cilia
• Early development protostomes
• Habitat ? water or moist dirt
• Basic body parts mouth, pharynx, intestine,
  ganglia, flame cells

19
Movement, Reproduction, Groups of Flatworms

• Groups of Flatworms
• Turbellarians (picture 1) free-living flatworms
  that live in marine or fresh water
• Bottom dwellers
• Flukes (picture 2) parasitic flatworms
• Infect the internal organs of their hosts
• Tapeworms (picture 3) long, flat, parasitic
  worms
• adapted to life inside the intestines of their
  hosts

• Free-living flatworms typically move in 2 ways
• Cilia help them glide through the water
• Muscle cells allow them to twist and turn
• Most free-living flatworms are hermaphrodites
  (have both male and female reproductive organs)
• Sexual reproduction involves joining in a pair
  and delivering sperm to each other
• Asexual reproduction takes place by fission
  where the organism splits in two and each half
  grows into a new organism

Picture 3
Picture 2
Picture 1
20
(No Transcript)
21
Phylum Nematoda ?Roundworms
22
Key Characteristics

• Three germ layers present ectoderm, mesoderm,
  endoderm
• unsegmented
• Bilateral symmetry
• Cephalization present
• Pseudocoelom present

• Mouth forms first protostome
• Basic body parts mouth, anus, intestines
• Ex. Pinworms, Nematodes

23
Roundworms

• Feeding most are carnivorous with grasping
  mouthparts and spines to catch and eat other
  animals
• Respiration, circulation, and excretion occurs
  via diffusion they have no internal transport
  system
• Response simple nervous systems consisting of
  several ganglia
• Movement muscles extend the length of their body
  and allow for movement
• Reproduction sexual, non-hermaphroditic

• Roundworms are unsegmented worms that have
  pseudocoeloms and digestive systems with two
  openings a mouth and an anus
• A pseudocoelom is a false coelom a body
  cavity lined only partially with mesoderm

24
Roundworms Human Disease

• These parasitic roundworms can cause disease
• Trichinella spiralis causes Trichinosis
• Humans can get it from eating undercooked pork
  that is infected with the parasite can cause
  nausea, heartburn, stomach aches, diarrhea
• Filarial worms can cause Loa loa filariasis
• A skin and eye disease transmitted through the
  bite of a horsefly causes itchy swellings below
  the eye or skin
• Ascaris lumbricoides causes Ascariasis
• Common infection often does not have any
  symptoms, but can cause diarrhea, fever, or
  inflammation
• Hookworms
• Affects up to1/4 people in the world they can
  burrow through skin and travel through the
  bloodstream to the lungs or intestine they suck
  the hosts blood causing weakness and poor growth

25
Phylum Annelida ? earthworms, leeches
26
Key Characteristics

• Three germ layers present
• Bilateral symmetry present
• Cephalization present
• True coelom present
• Segmentation present

• Movement ? Muscles
• Mouth develops first protostome
• Basic body parts mouth, anus, crop, gizzard,
  body segments
• Ex earthworm

27
Form Function of Annelids

• Feeding Digestion range from filter feeders to
  predators
• They extend their pharynx to collect prey and the
  food moves through the crop where it is stored
  and then through the gizzard where it is ground
  into smaller pieces
• Circulation they have a closed circulatory
  system
• Blood is contained within a network of blood
  vessels

• Respiration gills (aquatic annelids) and
  diffusion (land annelids)
• Excretion digestive wastes passes out through
  the anus and liquid waste is eliminated by
  nephridia (filter fluid)
• Response have well developed nervous systems
  that include a brain and several nerve cords
• Movement have 2 major groups of body muscles as
  part of a hydrostatic skeleton
• Reproduction most reproduce sexually (although
  some use external fertilization) and some are
  hermaphroditic

28
Groups of Annelids

• Oligochaetes Typically have streamlined bodies
  and relatively few setae (hairs) compared to
  polychaetes (most live in soil or fresh water)
• Leeches external parasites that suck the blood
  and body fluids of their host
• Polychaetes marine annelids that have paired,
  paddlelike appendages tipped with setae (hairs)

Polychaetes
Oligochaete
Leech
29
Phylum Molluska ?Clam Squid
30
Key Characteristics

• Ex. Clam, squid
• Three germ layers present ectoderm, mesoderm,
  endoderm
• Have an external or internal shell for support
• Bilateral symmetry Radial Symmetry (Squid)
• Cephalization present

• Segmentation present
• Movement ? w/ muscles
• Has a TRUE COELOM
• Mouth develops first protostome
• Basic body parts gills, specialized foot

31
Body plan other processes

• Respiration breathe using gills (aquatic) or by
  diffusion (land)
• Circulation either open or closed circulatory
  system
• Open - blood is pumped through vessels by a
  simple heart and then diffusion into other
  systems
• Closed blood is transported through the body
  much quicker than an open circulatory system and
  is always contained in vessels
• Excretion nephridia
• Response complexity of nervous systems varies
• Movement secretion of mucous or jet propulsion
• Reproduction sexually by external fertilization,
  sexually by internal fertilization, and some are
  hermaphrodites

• Body Plan contains 4 parts foot, mantle,
  shell, visceral mass
• The muscular foot has many forms, including flat
  structures for crawling, spade-shaped structures
  for burrowing, and tentacles for capturing prey
• The mantle is a thin layer of tissue that covers
  most of the mollusks body
• The shell is made by glands that secrete calcium
  carbonate and has been reduced or lost in snails
  and some other mollusks groups
• The visceral mass lies just below the mantle and
  contains the internal organs

32
Groups of Mollusks

• Gastropods shell-less or single-shelled mollusks
  that move by using a muscular foot located on the
  ventral side
• Pond snails, land slugs, sea butterflies
• Bivalves have two shells that are held together
  by one or two powerful muscles
• Clams, oysters, mussels, scallops
• Cephalopods soft-bodied with the head attached
  to a single food that is divided into tentacles
  or arms
• Octopi, squids, cuttlefish

Gastropod
Bivalve
Cephalopod
33
Giant Clam
34
(No Transcript)
35
Phylum Arthropoda ? Crayfish, Spider, Lobster,
Centipede
Anatomy of a Crayfish
36
Key Characteristics

• Three germ layers present
• Exoskeleton present that requires molting
  (shedding)
• Jointed appendages
• Bilateral symmetry
• Cephalization present
• True coelom present

• Segmentation present
• Movement ? Yes (muscles skeleton)
• Habitat ? In or Near Water
• Early Development ? Protostome
• Ex. Insects, spiders, crayfish, millipedes,
  centipedes

37
Crustacean Parts Decapods

• Cephalothorax formed by fusion of the head with
  the thorax (which houses most of the internal
  organs)
• Abdomen posterior part of the body
• Carapace part of the exoskeleton that covers the
  cephalothorax
• Mandible mouthpart adapted for biting and
  grinding food

• The largest group of crustaceans are the decapods
• They have 5 pairs of legs
• The 1st pair of legs are chelipeds and bear large
  claws
• The walking legs are the next pair
• Behind the walking legs are the swimmerets
  (flipper-like appendages for swimming
• Crayfishes, lobsters, and crabs are members of
  this group

38
Horseshoe Crabs

• Horseshoe crabs are among the oldest living
  arthropods.

39
Spiders Insects

• Horseshoe crabs, spiders, ticks, and scorpions
  are chelicerates
• They have 2 pairs of appendages attached near the
  mouth
• One pair are the chelicerae that includes fangs
• The other pair, the pedipalps, are modified to
  capture prey
• They have two body sections, a cephalothorax and
  abdomen
• nearly all have 4 pairs of walking legs
• They lack antennae
• They respire using book gills or lungs

• The largest group of arachnids are spiders
• Spiders are arthropods that do not have jaws for
  chewing, so they must liquefy their food to
  swallow it
• All spiders produce silk which is stronger than
  steel
• To spin silk into webs, spiders force liquid silk
  through spinnerets, which are organs that contain
  silk glands

40
Anatomy of Spider
Anatomy of Grasshopper
41
Insect Responses Metamorphosis

• The growth and development of insects usually
  involve metamorphosis
• Metamorphosis is the process of changing shape
  and form
• Most insects undergo either incomplete or
  complete metamorphosis
• Incomplete metamorphosis immature nymphs look
  much like adult form
• Complete metamorphosis immature larvae look
  nothing like parents

• Insects use a multitude of sense organs to
  respond to stimuli
• Compound eyes are made of many lenses
• Chemical receptors are used for taste and smell
• Sensory hairs detect slight movements in
  surrounding air or water
• Well developed ears detect sounds far above the
  human range

42
Insect Communication Societies

• Ants, bees, termites, and some of their relatives
  form complex associations called societies
• A society is a group of closely related animals
  of the same species that work together for the
  benefit of the whole group
• Within a society, individuals may be specialized
  to perform particular tasks in groups called
  castes

• Many insects communicate using chemical signals
  called pheromones
• Insects can also communicate using sound, visual,
  and other types of signals
• Insect communication usually involves finding a
  mate

43
Phylum Echinodermata ? Starfish, Sea urchins,
sand dollars, sea cucumbers
44
Key Characteristics

• Movement ? Tube feet water vascular system
• Anus forms first deuterostome!!! (the only
  invertebrate deuterostome)
• Basic body parts spiny skin, endoskeleton,
  water vascular system, tube feet
• Ex starfish

• 3 germ layers present
• Bilateral Radial symmetry (adults)
• No cephalization in adults
• True coelom present
• Segmentation present

45
Endoskeleton Water Vascular System

• Echinoderms are characterized by spiny skin, an
  endoskeleton (internal skeleton), a water
  vascular system, and suction-cuplike structures
  called tube feet.
• Most adult echinoderms exhibit five-part radial
  symmetry
• The body parts are arranged around a central body
  like the spokes of a wheel

• A unique feature of echinoderms is a system of
  internal tubes called a water vascular system
• This system is filled with fluid and carries out
  many essential body functions (respiration,
  circulation, movement)
• It opens to the outside through filter-like
  structures called madreporites
• A tube foot is a structure that operates much
  like a suction cup

46
Classes of Echinoderms

• Sea urchins and sand dollars
• Unique echinoderms in having large, solid plates
  that form a box around their internal organs
• Many detritivores Grazers
• Brittle Stars
• Common in coral reefs detritivores filter
  feeders
• Can shed one or more arms if attacked arm will
  distract their predators
• Sea Cucumbers
• Look like pickles detritus feeders that move
  across sea floor
• Sea Stars
• Carnivorous prey on bivalves
• Can repair itself ? when pulled apart, each
  section can become a new sea star if a portion of
  the central cavity still remains.
• Sea Lilies and Feather Stars
• Filter feeders with long, feathery arms
• Common in tropical oceans around coral reefs

47
(No Transcript)