2014 CABE

1. Photo by Kuntner M.
The function of body coloration
of the ladder web spider,
Herennia multipuncta
Speaker: Hsien-Chun Liao
Advisor: I-Min Tso

2. 2
Outlines
• Functions of body coloration
• Ventral and dorsal coloration
• Different colorations of an organism
exhibit different function?
• Study species introduction
• Field manipulation
• Conclusion and implication

3. Ventral and dorsal body colorations may
serve as different visual indicators.
3
(Molnár et al., 2012)
(García‐navas et al., 2012)
(Blount et al., 2012)
(Pegram et al., 2013)

4. Studies focusing on both ventral and dorsal
body coloration of an organism are rare.
4

5. 5
Defensive strategies
Primary defense mechanism
Secondary defense mechanism

6. 6
Aim
• Whether ventral and dorsal coloration
patterns of an organism exhibit
different function?
?

7. 7
Herennia multipuncata
Ladder web
(Made by Robbinson and Lubin)

8. 8
Herennia multipuncata
Dorsum
Dorsum
Ventrum

9. 9
Arboricolous type
Aerial type

10. Body colorations of Herennia spiders
may exhibit two different functions
10
Could the dorsal body
coloration of Herennia
function as a visual lure to
attract prey?

11. Body colorations of Herennia spiders
may exhibit two different functions
Whether the ventral coloration of Herennia
functions to defend spider against predation?
11

12. Testing visual lure function of dorsal
coloration of Herennia by dummies.
• July of 2012
• Subtropical forest in Nantou county, Taiwan
• Monitoring periods: 08:00~12:00, 20:00~00:00
• The video cameras were used to monitor the interactions
between prey and dummies of various treatments.
12

13. Colors signals of prosoma and abdomen
were manipulated.
13
Body parts of Herennia multipuncata
Both present Orange present
Gray present
Both removed
Relative quantum catch (%)
Papers and paint
used for making spider dummies
70
60
50
40
30
20
10
0
300
400
500
Wave length (nm)
600
700

14. Events recorded by video camera
- Orange bands present treatment
14

15. Events recorded by video camera
- Gray dorsum present treatment
15

16. The presence of orange bands enhanced
prey attraction significantly.
16
(Negative Binomial Regression, P = 0.032)
Diurnal prey attraction rate (#/hr)
0.30
With orange band
Orange band removed
0.25
0.20
0.15
Orange present
*
Both present
Both removed
Gray present
0.10
0.05
0
Black
Gray
Color of abdomen

17. The presence of both parts enhanced
prey attraction significantly at night.
17
(Negative Binomial Regression, P = 0.018, P = 0.029)
With orange band
Orange band removed
0.4
0.3
0.2
Orange present
Both present
Both removed
Gray present
*
0.1
*
Nocturnal prey attraction rate (#/hr)
0.5
0
Black
Gray
Color of abdomen

18. Prey composition is significantly different
between diurnal and nocturnal periods.
Prey composition (N)
50
40
Diptera
Lepidoptera
Hemiptera
Coleoptera
Orthoptera
30
20
10
0
18

19. Prey composition is significantly different
between diurnal and nocturnal periods.
50
Diptera
Prey composition (N)
Lepidoptera
40
Orthoptera
Other
30
20
10
0
Undentified
19

20. Testing anti-predator function of
ventral coloration
Japalura swinhonis
© DC comics
20

21. 21
Manipulative experiments
• The lizards were collected by hand in Tunghai campus.
• In the cages the interactions between lizard and spider were
recorded by digital video cameras.
• Each process was monitored for 4 hours.

22. 22
Flow chart of lizard and spider interactions
Encounter
Lizard leave
or
attack spider
Staring period
Spider push up
and
Lizard staring
Consumed
or survive?
Latency to attack
Approaching
spider again

23. Events recorded by video camera
- Consumption event of painted treatment
23

24. Painting treatment did not affect
push up rate of spiders.
24
(Two sample t-test, p = 0.7691)
Push up rate (#/sec.)
5
N.S.
4
3
2
1
0
N = 11
Control
treatment
N = 11
Experimental
treatment

25. 25
Testing anti-predator function of
ventrum coloration
(Two sample t-test, P = 0.0233)
Starring period
Lizard staring time (sec.)
Lizard go away
or
attack spider
150
*
120
90
60
30
0
Control
treatment
Experimental
treatment

26. 26
Testing anti-predator function of
ventrum coloration
(Two sample t-test, p = 0.007)
Consumed
or survive?
Latency to attack
Approaching
spider again
Latency to attack (hr.)
4
**
3
2
1
0
Control
treatment
Experimental
treatment

27. Two different functions of body
coloration may exist on H. multipuncata
• The first research on function of H. multipuncata
body coloration
• Visual lure function
• Startle display with conspicuous coloration
27

28. 28
Visual lures function differently in
diurnal and nocturnal time.
0.5
With orange band
Orange band removed
0.25
0.20
0.15
*
0.10
With orange band
Orange band removed
0.4
0.3
0.2
*
0.1
*
0.05
Nocturnal prey attraction rate (#/hr)
Diurnal prey attraction rate (#/hr)
0.30
0
0
Black
Dorsal part treatments
Gray
Black
Gray
Dorsal part treatments

29. Spiders with conspicuous ventrum
coloration seems to survive better.
• A good model to test the
hypothesis.
100
80
Survival rate (%)
• With orange ventrum
colouration, spiders had higher
fitness consequence of their
antipredation behavior.
60
40
20
0
4/7
10/11
Control
Experimental
treatment treatment
29

30. Body colorations as visual lure and
startle display
• The orange circular bands and gray
dorsal side play an essential role in
visually attracting prey.
• With conspicuous ventrum, spiders
have more time to escape and
survive better.
• An organism enhance foraging
success and survival rate by color
signals of different body parts.
30

31. 31
Thank you
for your attention

32. Three hypotheses about the functions
of deimatic behavior
1. Predator competition
• The captured animal’s conspicuous traits attract
other predators, and enables the prey to escape.
2. Convey information to a predator
• The information has an effect on decision that
the prey may manage to escape after having
been captured.
3. Startle display
32

33. The color signal of H. multipuncta and
tree trunk
Orange part of prosoma
dorsum
bark
Relative quantum catch (%)
100
prosoma
33
White part of dorsum
Orange part of ventral
Tree trunk
80
60
40
20
0
ventral
300
400
500
Wave length (nm)
600
700

34. Orb-weaving spider body coloration
attracts diurnal prey.
34
(Tso et al., 2004)
Nephila pilipes
Typical
Insect-catching rate (#/hr.)
Melanic
*
0.5
0.4
0.3
0.2
0.1
0
Melanic group
Typical group

35. Orb-weaving spider body coloration
attracts nocturnal prey.
35
(Chuang et al., 2008)
1.5
With spider
Without spider
Insect-catching rate (#/hr.)
Neoscona punctigera
***
1.0
0.5
0
With spider Without spider

36. The color signals of orange and gray parts of
dummies were similar to Herennia spiders.
Chromatic contrast
36
Achromatic contrast
0.35
0.2
0.25
0.15
Contrast
Contrast
0.15
0.1
0.05
-0.05
-0.15
0.05
-0.25
0
-0.35
Gray
Black
Orange
Gray
Black
Orange

37. Three hypotheses about the functions
of deimatic behavior
1. Predator competition
• The captured animal’s conspicuous traits attract other
predators, and enables the prey to escape.
2. Convey information to a predator
• The information has an effect on decision that the prey
may manage to escape after having been captured.
3. Startle display
37

38. Three hypotheses about the functions
of deimatic behavior
1. Predator competition
• The captured animal’s conspicuous traits attract other
predators, and enables the prey to escape.
2. Convey information to a predator
• The information has an effect on decision that the prey
may manage to escape after having been captured.
3. Startle display
38

39. The color signal of H. multipuncta and
tree trunk
39
dorsum
bark
100
Reletive reflectance (%)
prosoma
80
60
40
20
0
300
400
500
Wavelength (nm)
ventral
600
700

40. Three hypotheses about the functions
of deimatic behavior
1. Predator competition
• The captured animal’s conspicuous traits attract other
predators, and enables the prey to escape.
2. Convey information to a predator
• The information has an effect on decision that the prey
may manage to escape after having been captured.
3. Startle display
40

41. (Harmer, 2009)
Moth specialization
41
Optimal area use
Telaprocera sp.
• Coloration: Conspicuous
• Coloration: Dim
• Foraging period: Long
• Prey type:
Diptera and Lepidoptera
• Foraging period: Short
• Prey type:
Diptera and Coleoptera

42. Events recorded by video camera
- Survival event of control treatment
42

43. Events recorded by video camera
- Both present treatment
43

44. Events recorded by video camera
- Gray present treatment
44

45. Potential predators of arboricolous
ladder-web spiders
• Some organisms approaching spider dummy could
be regarded as potential predators.
• The foliage-gleaner bats may use both visual signal
and echo location to locate and attack prey
inhabiting tree trunks.
(Belwood, 1988)
45

46. 46
An effective anti-predator strategy
(Langkilde and Boronow, 2012)
• Short-term colour change in
some lizard species may aid
thermoregulation thus
provide a honest signal of a
male's physiological condition.
• The push-up movement
combining a conspicuous
color signal seems to become
an effective strategy.