Bicompartmental cyanide-producing gland in Apheloria virginiensis (chemical structures and reactions from Eisner & Meinwald, 1966)

*

Eisner, 2005

Motyxia

National Geographic / NatGeo WILDfilmed by Owen Bissell & Paul Marek

California

Nevada

Pacific Ocean

8 species of Motyxia

Of all the millipedes, only Motyxia glows*

0.2

Dicellarius_atlanta_

Motyxia_pior_MTX0022

Xystocheir_stenomacr

Motyxia_kerna_MTX012

Orophe_unicus_MTX012

Stenodesmus_tuobitus

Semionellus_placidus

Sigmocheir_furcata_M

Harpaphe_haydeniana_

Wamokia_hoffmani_MTX

Xystocheir_nsp_MTX03

Motyxia_sequoia_alia

Oxidus_gracilis_MTX0

Parcipromus_tiemanni

Dynoria_medialis_SPC

Motyxia_tularea_olla

Metaxycheir_prolata_

Isaphe_convexa_MTX01

Anombrocheir_bifurca

Anombrocheir_spinosa

Xystocheir_stolonife

Motyxia_sequoia_sequ

Xystocheir_dissecta_

Xystocheir_solenofur

Brachoria_cumberland

Wamokia_remota_MTX03

Melaphe_vestita

Nearctodesmus_salix_

Wamokia_falcata_MTX0

Ochthocelata_adynata

Xystocheir_brachymac

Chonaphe_armata_MTX0

Motyxia_tiemanni_MTX

Xystodesmus_sp_MTX01

Motyxia_porrecta

Wamokia_dentata_MTX0

Xystocheir_prolixora

Xystocheir_mmodestio

Parcipromus_gigantoa

Motyxia_tularea_tula

Xystocheir_bistipita

Montaphe_elrodi_MTX0

Wamokia_sierrae_MTX0

Wamokia_discordis_MT

Parafontaria_tonomin

Wamokia_placera_MTX0

Xystocheir_mhaerens_

Parcipromus_cooki_MT

Motyxia_monica_MTX00

Selenocheir_sinuata_

Xystocheir_reducta_M

Riukiaria_holstii_MT

Motyxia_sequoiae_MTX

Apheloria_montana_SP

Orophe

Isaphe

Ochthocelata

Brachoria

Motyxia

Parcipromus

Xystocheir

Molecular phylogeny of Motyxia and relatives: estimated with mt & nDNA (16S, 12S, 28S, EF1a)

Motyxia

monica pior kerna

sequoiae

tulareaporrectatiemanni0.00.100.200.300.400.50

Modified from con 50 majrule+

Wamokia remota MTX03

Wamokia discordis MT

Wamokia placera MTX0

Wamokia sierrae MTX0

Wamokia hoffmani MTX

Wamokia falcata MTX0

Wamokia dentata MTX0

Anombrocheir spinosa

Anombrocheir bifurca

Xystocheir solenofur

Xystocheir brachymac

Xystocheir prolixora

Xystocheir dissecta

Xystocheir nsp MTX03

Xystocheir mmodestio

Xystocheir mhaerens

Xystocheir reducta M

Xystocheir stolonife

Xystocheir stenomacr

Parcipromus tiemanni

Parcipromus cooki MT

Parcipromus gigantoa

Motyxia tularea olla

Motyxia sequoia alia

Motyxia sequoia sequ

Motyxia kerna MTX012

Motyxia sequoiae MTX

Motyxia tiemanni MTX

Motyxia porrecta

Motyxia tularea tula

Motyxia pior MTX0022

Motyxia monica MTX00

Xystocheir bistipita

Sigmocheir furcata M

Selenocheir sinuata

Harpaphe haydeniana

Metaxycheir prolata

Orophe unicus MTX012

Isaphe convexa MTX01

Montaphe elrodi MTX0

Chonaphe armata MTX0

Ochthocelata adynata

Stenodesmus tuobitus

Character: LnSpMeanGParsimony reconstruction (Linear) [Length: 9.567]

-0.508 to 0.049142860.04914286 to 0.606285710.60628571 to 1.163428571.16342857 to 1.720571431.72057143 to 2.277714292.27771429 to 2.834857142.83485714 to 3.3920

0.00.100.200.300.400.50

Modified from con 50 majrule+

Wamokia remota MTX03

Wamokia discordis MT

Wamokia placera MTX0

Wamokia sierrae MTX0

Wamokia hoffmani MTX

Wamokia falcata MTX0

Wamokia dentata MTX0

Anombrocheir spinosa

Anombrocheir bifurca

Xystocheir solenofur

Xystocheir brachymac

Xystocheir prolixora

Xystocheir dissecta

Xystocheir nsp MTX03

Xystocheir mmodestio

Xystocheir mhaerens

Xystocheir reducta M

Xystocheir stolonife

Xystocheir stenomacr

Parcipromus tiemanni

Parcipromus cooki MT

Parcipromus gigantoa

Motyxia tularea olla

Motyxia sequoia alia

Motyxia sequoia sequ

Motyxia kerna MTX012

Motyxia sequoiae MTX

Motyxia tiemanni MTX

Motyxia porrecta

Motyxia tularea tula

Motyxia pior MTX0022

Motyxia monica MTX00

Xystocheir bistipita

Sigmocheir furcata M

Selenocheir sinuata

Harpaphe haydeniana

Metaxycheir prolata

Orophe unicus MTX012

Isaphe convexa MTX01

Montaphe elrodi MTX0

Chonaphe armata MTX0

Ochthocelata adynata

Stenodesmus tuobitus

Character: LnSpMeanGParsimony reconstruction (Linear) [Length: 9.567]

-0.508 to 0.049142860.04914286 to 0.606285710.60628571 to 1.163428571.16342857 to 1.720571431.72057143 to 2.277714292.27771429 to 2.834857142.83485714 to 3.3920bright

faint

bioluminescenceWhy bioluminescence?

• Mate recognition?

• Attract prey?

• Avoid predation?

• No function?

Hypothesis:

luminescence is an aposematic signal

Hypothesis:

luminescence is an aposematic signal

The glow means “no”

Testing the hypothesis

• Field experiment1. Luminescent and non-luminescent clay

millipedes

2. Live millipedes, half with luminescence concealed with paint

luminescentnon-luminescent

�

�

�

�

��

�

More predator attacks on the non-luminescent millipedes

Predictions:

Experimental design

• 300 clay millipedes- 150 luminescent- 150 non-luminescent

• 164 live millipedes- 82 luminescent- 82 non-luminescent (painted)

���

100 clay millipedes & 20 live millipedes

G-test: G = 14.84df = 1, P < 0.001*

Proportion attacked vs. Luminescence

G-test: G = 7.72df = 1, P = 0.005*

Marek et al., 2011. Current Biology

California Academy of SciencesSan Francisco, California

Mammal Skull Collection

Summary

• Single evolutionary origin of luminescence in millipedes (8 out of 12,000 spp.)

• Luminescence serves as a predator deterrent (aposematic)

• Unique innovation endemic to a small sliver of California

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

Future work: Evolution of Bioluminescence

0.00.100.200.300.400.50

Modified from con 50 majrule+

Wamokia remota MTX03

Wamokia discordis MT

Wamokia placera MTX0

Wamokia sierrae MTX0

Wamokia hoffmani MTX

Wamokia falcata MTX0

Wamokia dentata MTX0

Anombrocheir spinosa

Anombrocheir bifurca

Xystocheir solenofur

Xystocheir brachymac

Xystocheir prolixora

Xystocheir dissecta

Xystocheir nsp MTX03

Xystocheir mmodestio

Xystocheir mhaerens

Xystocheir reducta M

Xystocheir stolonife

Xystocheir stenomacr

Parcipromus tiemanni

Parcipromus cooki MT

Parcipromus gigantoa

Motyxia tularea olla

Motyxia sequoia alia

Motyxia sequoia sequ

Motyxia kerna MTX012

Motyxia sequoiae MTX

Motyxia tiemanni MTX

Motyxia porrecta

Motyxia tularea tula

Motyxia pior MTX0022

Motyxia monica MTX00

Xystocheir bistipita

Sigmocheir furcata M

Selenocheir sinuata

Harpaphe haydeniana

Metaxycheir prolata

Orophe unicus MTX012

Isaphe convexa MTX01

Montaphe elrodi MTX0

Chonaphe armata MTX0

Ochthocelata adynata

Stenodesmus tuobitus

Character: LnSpMeanGParsimony reconstruction (Linear) [Length: 9.567]

-0.508 to 0.049142860.04914286 to 0.606285710.60628571 to 1.163428571.16342857 to 1.720571431.72057143 to 2.277714292.27771429 to 2.834857142.83485714 to 3.3920

0.00.100.200.300.400.50

Modified from con 50 majrule+

Wamokia remota MTX03

Wamokia discordis MT

Wamokia placera MTX0

Wamokia sierrae MTX0

Wamokia hoffmani MTX

Wamokia falcata MTX0

Wamokia dentata MTX0

Anombrocheir spinosa

Anombrocheir bifurca

Xystocheir solenofur

Xystocheir brachymac

Xystocheir prolixora

Xystocheir dissecta

Xystocheir nsp MTX03

Xystocheir mmodestio

Xystocheir mhaerens

Xystocheir reducta M

Xystocheir stolonife

Xystocheir stenomacr

Parcipromus tiemanni

Parcipromus cooki MT

Parcipromus gigantoa

Motyxia tularea olla

Motyxia sequoia alia

Motyxia sequoia sequ

Motyxia kerna MTX012

Motyxia sequoiae MTX

Motyxia tiemanni MTX

Motyxia porrecta

Motyxia tularea tula

Motyxia pior MTX0022

Motyxia monica MTX00

Xystocheir bistipita

Sigmocheir furcata M

Selenocheir sinuata

Harpaphe haydeniana

Metaxycheir prolata

Orophe unicus MTX012

Isaphe convexa MTX01

Montaphe elrodi MTX0

Chonaphe armata MTX0

Ochthocelata adynata

Stenodesmus tuobitus

Character: LnSpMeanGParsimony reconstruction (Linear) [Length: 9.567]

-0.508 to 0.049142860.04914286 to 0.606285710.60628571 to 1.163428571.16342857 to 1.720571431.72057143 to 2.277714292.27771429 to 2.834857142.83485714 to 3.3920bright

faint

Acknowledgements

• Wendy Moore

• Dan Papaj

• Jason Bond

• David Maddison

• Charity Hall

• Rob Marek

‣ National Science Foundation

‣ National Institutes of Health

‣ National Geographic Society

‣ Postdoctoral Excellence in Research and Teaching (PERT)

‣ University of Arizona, Center for Insect Science

National GeographicO. Bissell & P. Marek

Image credits

• Cyanohydrin reaction, T. Eisner

• Yakking toad, T. Eisner

• Motyxia gonopods, R. Shelley

• Firefly, J. Jordan

• Distremocephalus, A. Yelich

• Bioluminescent click beetle, A. Tween