Animal Behavior
Observing Isopods Lab
KINESIS AND TAXIS
Animal Behavior
 Part A: Response to Environmental Variables
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Activity A1: Initial Observation of Isopod Behavior
Activity A2: Orientation Behavior of Isopods
Activity A3: Designing an Experiment to Test
Isopod Behavior
National Science Education
Standards
 Unifying Concepts and Processes
 Systems, order, and organization
 Evidence, models, and explanation
 Constancy, change, and measurement
 Science as Inquiry
 Abilities necessary to do scientific inquiry
 Understandings about scientific inquiry
 Life Science
 Behavior of organisms
Objectives
 Observe animal behaviors relating to
environmental stimuli
 Learn types of taxis behavior
 Design and conduct animal behavior
experiments
Isopods
 Terrestrial Isopods
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Sow bugs (Porcellio laevis) and pill bugs
(Armadillidium vulgare)
 Roly-polies, potato bugs, wood lice
Breathe with gills, must remain moist
Similar size, color, and life cycle
Different Response to threats
 Pill bugs- curl up in tight ball for protection
 Sow bugs- either flee or remain perfectly still,
appearing to be dead
Classification
 DOMAIN - Eukaryotes
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KINGDOM - Animalia
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PHYLUM – Arthropod
Phylum)
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(Crustacean – Sub
CLASS – Malacostraca
ORDER - Isopoda
FAMILY – Armadillidiidae
GENUS –
SPECIES -
 More closely related to other crustaceans
(lobster and shrimp) than insects.
Description: Adults grow to about
3/8 inch long, have a number of
rounded body segments and seven
pairs of legs.
Sowbugs possess a pair of tail-like
structures on the back end of the
body.
Pillbugs do not have these structures
and are capable of rolling into a tight
ball when disturbed, a behavior that
resulted in their common
name, "roly-polies."
Pillbug Natural History
 3800 known species
 12-15 species exist in U.S. all came from Europe in
the early 1800’s
 At humidy >87% can absorb water from water
vapor.
 Nocturnal (lose water while foraging)
 Born in mother’s pouch with 6 pairs of legs, after
first molt have seven pairs and leave
 Must molt every 2-3 weeks to grow
 Live 2-3 years
Significance
 are important decomposers
 may occasionally feed on roots,
 should not be regarded as pests.
 they remove many of the toxic metal ions from
the soil.
Appearance (Morphology)
 Three body parts: head, thorax, abdomen
 One prominent pair of antennae (one
inconspicuous pair)
 Simple eyes
 Seven pairs of legs
 Seven separate segments on thorax
 Paired appendages at end of abdomen called
uropods
 Color varies from dark gray to white with or
without pattern
Pillbug Anatomy
 http://somethingscrawlinginmyhair.com/2013/
03/16/pillbugswoodliceroly-polysetc/
 White spots and other observations
Behavior Information
Taxes and kineses are
simple orientation
responses which can
maintain an organism in a
favorable environment.
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Taxes
 Taxes are movements by an animal towards or
away from an environmental stimulus.
 Movement towards a stimulus is a positive
taxis, and movement away from a stimulus is a
negative taxis.
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Types of Taxes
The type of the stimulus is shown by
prefixes:
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PhotoGeoHydroChemoThigmoThermo -
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Light
Gravity
Water
Chemicals
Touch
Heat
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Examples of Taxes
•A maggot placed on a sheet of paper will move
randomly on the paper if the light source is uniform.
•If a light is switched on coming from one direction only, the
maggot will move away from the light. This is a negative
phototaxis.
•The advantage of this taxis to the maggot (and many other
small invertebrates) is that moving away from light will take
the maggot to a place of shelter where predators will not be
able to get at them.
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•The female silk moth releases a pheromone called
bombykol. A male silk moth is able to detect single
molecules of this substance and fly in the direction of
the female in order to mate with her. He does this by
having two antennae sensitive to the chemical on
either side of his head. He will turn to whichever
antennae detects the most bombykol.
• This is an example of positive chemotaxis.
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Positive
Chemotaxis
White blood
cells move
towards the
chemicals
released by
inflamed and
damaged
tissues.
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If the behaviour is
movement in the
direction of the
stimulus or away
from the stimulus
then it is most likely
a taxis.
How do I recognise a
taxis?
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Positive towards Stimulus
STIMULUS
Negative Away from Stimulus
Euglena – Positive Phototaxic
SHOW EXAMPLE FROM EOC
Positive towards Stimulus
STIMULUS
Negative Away from Stimulus
Moth – Positive Phototaxic
Positive towards Stimulus
STIMULUS
Negative Away from Stimulus
Earthworm – Negative Phototaxic
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Kinesis and taxis are two types of movement-related behaviors.
– Taxis is movement in a particular direction either toward or away
from a stimuli
–Example: deer running away from rustling in the brush
– Kinesis is an increase in random movement.
Example: Pill bugs increase activity as they dry out to find moist
areas
Kinesis
 A kinesis is a random movement response to an
environmental stimulus that is not oriented
toward or away from a stimulus. It is nondirectional. (Like nastic responses in plants).
 The rate of movement of an animal varies with
the intensity of the stimulus.
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Kinesis - Cockroaches
 A The stimulus is. It is
non-directional.
 The rate of movement of
an animal varies with the
intensity of the stimulus.
When cockroaches are
exposed to light, they do
not move towards or away
from the light they just
scatter.
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Procedure- Activity 1
 Observe the isopods for 10 minutes.
 Observe in their undisturbed behavior
 Note their behavior.
 Did you note any agonistic behavior (social
interaction)?
 Are the movements of the isopods better
described as taxis or kinesis movements?
Procedure- Activity 2
 Place clean filter paper into each side of the
choice chamber.
 Using the dropping pipet, saturate the filter
paper on one side of the chamber. Pour off
any excess water; do not let the water run
into the other side of the chamber or
moisten the paper there.
 Using the sorting brush to transfer 5
isopods to the middle of the chamber
 Count and record in Table 1 the number of
animals on each side of the chamber, every
30 seconds for 10 minutes. Continue to
record even if the isopods all move to one
side or stop moving.
Repeat data collection from part 2, graph – Write Conclusion, Prepare to share.
Procedure: Activity 3
 Design an experiment to test isopod behavior
Choice
Chamber Side 1
Chamber Side 2
Cool vs. Warm #2
Resealable plastic bag filled
with ice
Resealable plastic bag filled
with warm water
Light vs. Dark
#7
Exposed to light
Wrapped with aluminum foil
Light vs. Shade
#5
Exposed to light
Covered with several screens
Low pH vs. Neutral #4
A few drops of HCL on filter
paper
Distilled Water on filter paper
High pH vs. Neutral #6
A few drops of NaOH
Distilled Water on filter paper
Substrate material vs.
Absence of substrate
material #8
Substrate (soil) material
present
Substrate (soil) material
absent.
Food material vs. Absence
of food material #1
Food material present
Food material absent.
 2 Cold vs. Warm
 7. light vs dark
 #5 Light vs. Shade
 #4 Low ph vs neutral
 #8 Substrate vs no substrate
 #6 High pH vs. neutral
 #1
Food vs. No Food