Introduction M

1
Host specificity, spatial niche diversity and
adaptations of coral-associated gobies in the
northern Red Sea
J. Herler, M. Dirnwöber, L. Schiemer, S.
Niedermueller
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Introduction MM Results Discussion

• Overview
• Short introduction to coral-associated gobies
• Brief overview about methods (DNA, habitats,
  shape)
• Results and discussion of molecular, ecological
  and morphological analyses
• Research perspectives

Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Thumbnail gobies size range 9 50 mm SL

• Bi-directional sex changers
• Hypoxia tolerance (Gobiodon)
• Toxic skin (Gobiodon)
• Specific habitat choice
• Competitive hierarchy (Gobiodon)
• Munday, Nilsson, Schubert and others

Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
1 cm
Bryaninops
Paragobiodon
Gobiodon
Eviota
Trimma
Pleurosicya
Diversity Indo-Pacific 160 200 species Red
Sea 30 species reported
Priolepis
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion

• Ecological data
• 5-10 x 1m belt transects
• Random swims, random plots
• Aquarium experiments

• Morphological data
• Traditional morphometrics (cluster, size
  constraints)
• Geometric morphometrics (shape variation within
  Gobiodon)

• Molecular data
• Partial sequences of mitochondrial genes 12S
  rRNA,
• 16S rRNA and cyt b

Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Molecular tree 12S, 16S, cyt b Consensus of
NJ, MP, ML, BI
(NJ)
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Ppro Bnat Byon Pmic Brid Egut Epra Esee Ezeb Tav
i Tmen Edis Psem Gsp2 Gcit Gret Griv Gsp1 Ghis Gs
p3 Pech
Morphometric Tree
Bray Curtis similarity
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Zone specialist
Microhabitat generalists
Microhabitat specialists
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Geometric morphometrics
RW 1
RW 2
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Regressions of RW1 (GM) against body size, depth
and width
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
G. histrio shows a split in the increase and
lower variation in body depth with growth than
G. rivulatus.
Both species show a reduction of their head width
during growth but this is stronger in G. histrio.
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Acropora digitifera
Acropora acuminata
interbranch space (mm)
coral colony size (mm)
Gobiodon rivulatus
Gobiodon histrio
max. head width (mm)
fish body length (mm)
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
Aquarium experiments swimming performance
G. histrio G. rivulatus
minimal interbranch distance passed (mm)
fish size (mm SL)
Herler et al., ICRS 2008 Coral gobies
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Introduction MM Results Discussion
PMI
Different species of Acropora host corals show
different susceptibility to stress PMI partial
mortality index
Breeding pairs of gobies prefer corals with
little or no damage Occupation of undamaged
colonies 5 x occupation of corals with PM gt 70
Herler et al., ICRS 2008 Coral gobies
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P-10.374
Herler et al., ICRS 2008 Coral gobies
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Perspectives
Adaptations to microhabitats Important traits
for ecological performance? Fitness consequences
of the use of alternative habitats after habitat
loss? Goby-coral associations What kind of
relationship is it mutualism, commensalism?
Parallel evolution between coral and
fish? Diversification Is there additional
ecological/morphological diversification other
than spatial niche diversification, for example
trophic niche differentiation?
Herler et al., ICRS 2008 Coral gobies
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• Many thanks to ...
• Austrian Academy of Sciences
• Moustafa Fouda (EEAA, Egypt)
• Ayman Mabrouk (Nabq MPRA, Egypt)
• Helge Hilgers (University of Vienna, Austria)
• Phil Munday (JCU, Australia)
• Carden Wallace (MTQ, Australia)
• Rick Winterbottom (ROM, Canada)
• my students Markus, Mona, Lucie, Marlene, Eva
• Dahab Association for Environmental Development
• ICRS committee
• millions of gobies that (still) exist
• you, for your attention