Title: Invertebrates Survey Lab
1Invertebrates Survey Lab
2Characteristics 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
3Key Terms to Know
4Key Terms to Know
5Key Terms to Know
A tube within a tube
6Key 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.
7Key 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
8Key Concept to Know
9Phylum Porifera ? Sponges
10Key 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
11Ecology 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
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13Phylum Cnidaria ? Jellyfish, Sea anemones, corals
14Key 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
16Cnidarian 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)
17Phylum Platyhelminthes ? Flatworms
18Key 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
19Movement, 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
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21Phylum Nematoda ?Roundworms
22Key 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
23Roundworms
- 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
24Roundworms 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
25Phylum Annelida ? earthworms, leeches
26Key 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
27Form 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
28Groups 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
29Phylum Molluska ?Clam Squid
30Key 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
31Body 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
32Groups 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
33Giant Clam
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35Phylum Arthropoda ? Crayfish, Spider, Lobster,
Centipede
Anatomy of a Crayfish
36Key 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
37Crustacean 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
38Horseshoe Crabs
- Horseshoe crabs are among the oldest living
arthropods.
39Spiders 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
40Anatomy of Spider
Anatomy of Grasshopper
41Insect 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
42Insect 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
43Phylum Echinodermata ? Starfish, Sea urchins,
sand dollars, sea cucumbers
44Key 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
45Endoskeleton 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
46Classes 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
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