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

2. 2Outlines 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(Molnr et al., 2012)(Garcanavas 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. 5Defensive strategiesPrimary defense mechanismSecondary defense mechanism 6. 6Aim Whether ventral and dorsal coloration patterns of an organism exhibit different function?? 7. 7Herennia multipuncataLadder web(Made by Robbinson and Lubin) 8. 8Herennia multipuncataDorsumDorsumVentrum 9. 9Arboricolous typeAerial type 10. Body colorations of Herennia spiders may exhibit two different functions10Could 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.13Body parts of Herennia multipuncataBoth present Orange presentGray presentBoth removedRelative quantum catch (%)Papers and paint used for making spider dummies 7060 50 40 30 20 10 0 300400500 Wave length (nm)600700 14. Events recorded by video camera - Orange bands present treatment14 15. Events recorded by video camera - Gray dorsum present treatment15 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 removed0.250.20 0.15Orange present*Both presentBoth removedGray present0.10 0.05 0Black 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 removed0.40.30.2Orange presentBoth presentBoth removedGray present*0.1*Nocturnal prey attraction rate (#/hr)0.50BlackGray Color of abdomen 18. Prey composition is significantly different between diurnal and nocturnal periods.Prey composition (N)50 40Diptera Lepidoptera Hemiptera Coleoptera Orthoptera30 20 10018 19. Prey composition is significantly different between diurnal and nocturnal periods. 50DipteraPrey composition (N)Lepidoptera40Orthoptera Other30 20 10 0Undentified19 20. Testing anti-predator function of ventral colorationJapalura swinhonis DC comics20 21. 21Manipulative 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. 22Flow chart of lizard and spider interactionsEncounterLizard leave or attack spiderStaring periodSpider push up and Lizard staringConsumed or survive?Latency to attackApproaching spider again 23. Events recorded by video camera - Consumption event of painted treatment23 24. Painting treatment did not affect push up rate of spiders.24(Two sample t-test, p = 0.7691)Push up rate (#/sec.)5N.S.4 3 2 1 0N = 11 Control treatmentN = 11 Experimental treatment 25. 25Testing anti-predator function of ventrum coloration(Two sample t-test, P = 0.0233)Starring periodLizard staring time (sec.)Lizard go away or attack spider150*120 9060 300 Control treatmentExperimental treatment 26. 26Testing anti-predator function of ventrum coloration(Two sample t-test, p = 0.007)Consumed or survive?Latency to attackApproaching spider againLatency to attack (hr.)4**3210 Control treatmentExperimental 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 coloration27 28. 28Visual lures function differently in diurnal and nocturnal time. 0.5With orange band Orange band removed0.250.200.15*0.10With orange band Orange band removed 0.40.30.2*0.1*0.05Nocturnal prey attraction rate (#/hr)Diurnal prey attraction rate (#/hr)0.3000Black Dorsal part treatmentsGrayBlackGray Dorsal part treatments 29. Spiders with conspicuous ventrum coloration seems to survive better. A good model to test the hypothesis.100 80Survival rate (%) With orange ventrum colouration, spiders had higher fitness consequence of their antipredation behavior.60 40 20 04/7 10/11 Control Experimental treatment treatment29 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. 31Thank you for your attention 32. Three hypotheses about the functions of deimatic behavior 1. Predator competition The captured animals conspicuous traits attractother 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 display32 33. The color signal of H. multipuncta and tree trunk Orange part of prosomadorsumbarkRelative quantum catch (%)100 prosoma33White part of dorsum Orange part of ventral Tree trunk80 60 40 20 0ventral300400500 Wave length (nm)600700 34. Orb-weaving spider body coloration attracts diurnal prey.34(Tso et al., 2004)Nephila pilipesTypicalInsect-catching rate (#/hr.)Melanic*0.5 0.40.30.2 0.1 0Melanic groupTypical group 35. Orb-weaving spider body coloration attracts nocturnal prey.35(Chuang et al., 2008) 1.5With spiderWithout spiderInsect-catching rate (#/hr.)Neoscona punctigera*** 1.00.50With spider Without spider 36. The color signals of orange and gray parts of dummies were similar to Herennia spiders. Chromatic contrast36Achromatic contrast0.350.20.25 0.15ContrastContrast0.150.10.05 -0.05 -0.150.05-0.250-0.35GrayBlackOrangeGrayBlackOrange 37. Three hypotheses about the functions of deimatic behavior 1. Predator competition The captured animals conspicuous traits attract otherpredators, 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 display37 38. Three hypotheses about the functions of deimatic behavior 1. Predator competition The captured animals conspicuous traits attract otherpredators, 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 display38 39. The color signal of H. multipuncta and tree trunk39dorsumbark100 Reletive reflectance (%)prosoma80 60 40 20 0 300400500 Wavelength (nm)ventral600700 40. Three hypotheses about the functions of deimatic behavior 1. Predator competition The captured animals conspicuous traits attract otherpredators, 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 display40 41. (Harmer, 2009)Moth specialization41Optimal area useTelaprocera 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 treatment42 43. Events recorded by video camera - Both present treatment43 44. Events recorded by video camera - Gray present treatment44 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. 46An 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.