J. Herler, M. Dirnwöber, L. Schiemer, S. Niedermueller
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies 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
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies „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
Gobiodon Bryaninops Eviota Paragobiodon Diversity Indo-Pacific: 160 – 200 species Red Sea: ~ 30 species reported Pleurosicya Trimma IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies 1 cm Priolepis
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies 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
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies Molecular tree: 12S, 16S, cyt b Consensus of NJ, MP, ML, BI (NJ)
Ppro Bnat Byon Pmic Brid Egut Epra Esee Ezeb Tavi Tmen Edis Psem Gsp2 Gcit Gret Griv Gsp1 Ghis Gsp3 Pech IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies Morphometric Tree coral rock live coral Bray Curtis – similarity
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies Microhabitat generalists Zone specialist Microhabitat specialists
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies Geometric morphometrics RW 1 RW 2
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies Regressions of RW1 (GM) against body size, depth and width
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies 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.
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies interbranch space (mm) max. head width (mm) coral colony size (mm) fish body length (mm) Threshold Acropora digitifera Acropora acuminata Gobiodon histrio Gobiodon rivulatus
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies Aquarium experiments: swimming performance 15% size diff. G. histrio G. rivulatus coral inter- branch space range fish size (mm SL) minimal interbranch distance passed (mm)
IntroductionM&MResults & Discussion Herler et al., ICRS 2008: Coral gobies 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 > 70% PMI:
Herler et al., ICRS 2008: Coral gobies P
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
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