1 Supplementary materialTable S1 Summary information from representative studies on fish eco-morphology. Functional trait Deformation Eco-morphological relationships Reference Ref. # Carassius carassius (Linnaeus, 1758) Deep body Fish exposed to predator pressure displaying deeper bodies. Poléo et al. (1995) 1 Coregonus clupeaformis (Mitchill, 1818) Normal vs dwarf morphotypes Dwarf ecotype feeding almost on zooplankton. Bernatchez et al. (1999) Pigeon et al. (1997) 2 Coregonus lavaretus (L., 1758) Longer heads, large eyes, longer pectoral fins Specializing in feeding on deep and littoral resources. Siwertsson et al. (2013) 3 Cyprinella venusta (Girard, 1859) Deep vs fusiform body Deep-bodied morphotypes strongly correlated with lotic environment. Haas et al. (2010) 4 Gambusia affinis (Baird & Girard, 1853) Large caudal region and shallower anterior region Trade-off between burst swimming ability and prolonged swimming ability for feeding. Langerhans et al. (2004) 5 Gasterosteus aculeatus (L., 1758) Deep vs fusiform body Deep bodies correlated to benthic and bottom invertebrate foraging. Walker (1997) 6 Lepomis gibbosus (L., 1758) and Ambloplites rupestris (Rafinesque, 1817) Deep vs slender body Stream fishes displaying slender body depth. Brinsmead & Fox (2002) 7 Perca fluviatilis (L., 1758) Deep vs fusiform body Pelagic lifestyle correlated with fusiform morphotype; littoral lifestyle correlated with deep-bodied morphotype. Hjelm et al. (2001) 8 Rutilus rutilus (L., 1758) Deep vs fusiform body Stream fishes displaying greater pre-dorsal length; lake fishes displayed greater pectoral–pelvic fin distance. Rechulicz & Kolejko (2012) 9 6 species (multi-species approach) Deep body Combined with pharyngeal and jaw bones deep bodies correlated Pfaender et al. (2010) with suction feeding mode, as opposed to predatory foraging. 10 27 species (meta-analysis) Anterior part of body Fish displaying greater hydrodynamic potential have longer anterior part of body. 11 35 species (meta-analysis) Multivariate traits adaptation Water flow drives predictable phenotypic variation on a common Langerhans (2008) generalized model. 12 Amphilophus zaliosus (Barlow, 1976) Thick vs thin lips| Thick-lipped fishes feeding on benthic crustaceans and insect prey; thin lip fishes eating more littoral prey such as mollusks. Elmer et al. (2010) 13 Anguilla anguilla (L;, 1758) Large vs small mouth Fish feeding associated with large mouth; chironomid feeding associated with small mouth. Lammens & Visser (1989) 14 Body Sagnes & Statzner (2009) Trophic Astyanax mexicanus (De Filippi, 1853) Normal vs larger width size Large width correlated with increase in taste buds number in cavefish. Yamamoto et al. (2009) 15 Coregonus maraena (Bloch, 1779) Elongated snout Feeding on benthic prey. Kottelat & Freyhof (2007) 16 Coregonus oxyrinchus (L., 1758) Long pointed snout Feeding on zooplankton and benthic invertebrates. Kottelat & Freyhof (2007) 17 Coregonus widegreni (Malmgren, 1863) Elongated snout Kottelat & Freyhof (2007) 18 Garra lamta (F. Hamilton, 1822) Lip keratinized horny sheaths Scraping food material and browsing in stream environment. Pinky et al. (2002) 19 Leuciscus oxyrrhis (La Blanchère, 1873) Pointed projected snout Feeding on vegetal matter. Kottelat & Freyhof (2007) 20 European barbels Elongated snout Living near bottom in variety of habitats. Kottelat & Freyhof (2007) 21 10 species (multi-species approach) Trade-off between taste buds number and vision system Taste buds number increasing in benthic feeding species Gomahr et al. (1992) 22 Prosopium williamsoni (Girard, 1856) ‘Pinocchio’ deformation associated with fusiform body shape Elongated snout used for overturning substrate and feeding on benthic invertebrates (as opposed to feeding on drifting prey). Whiteley (2007) 23 Salvelinus alpinus (L., 1856) Deep and small body vs large body morphotypes Deeper and small body morphotype associated with soft bottom invertebrates foraging and deep water lifestyle. Knudsen et al. (2006) 24 Several head and body traits Enhanced maneuvrability and suction in complex habitats (i.e. rocky vs pebbly). Komiya et al. (2011) 25 Deep and small body vs large and fusiform body Water velocity correlated with size-related variables. Water depth correlated with fusiform and elongated body. Wikramanayake (1990) 26 Feeding on benthic invertebrates. Body and trophic Sarcocheilichtys (two species) 12 species (multi-species approach) 2 3 Bernatchez, L., Chouinard, A. & Lu, G. (1999). Integrating molecular genetics and ecology in studies of adaptive radiation: whitefish, Coregonus sp., as a case study. Biol. J. Linn. Soc. Lond. 68, 173–194. 4 Gomahr, A., Palzenberger, M. & Kotrschal, K. (1992).Density and distribution of external taste buds in cyprinids. Environmental Biology of Fishes, 33(1-2), pp.125–134. 5 Hjelm, J. et al., 2001.Diet-dependent body morphology and ontogenetic reaction norms in Eurasian perch. Oikos, 95, 311–323. 6 Knudsen, R., Klemetsen, A., Amundsen, P.A. & Hermansen, B., (2006). Incipient speciation through niche expansion: an example from the Arctic charr in a subarctic lake. P. 7 Roy. Soc. B-Biol. Sci. 273, 2291–2298. 8 Langerhans, R., Layman, C.A., Shokrollahi, A.M. & DeWitt, T.J. (2004). Predator-driven phenotypic diversification in Gambusia affinis. Evolution 58, 2305–2318. 9 Langerhans, R.B. (2008). Predictability of phenotypic differentiation across flow regimes in fishes. Integr. Comp. Biol., 48, 750–768. 10 11 12 13 14 15 16 17 18 19 Pfaender, J., Schliewen, U.K. & Herder, F. (2010). Phenotypic traits meet patterns of resource use in the radiation of “sharpfin” sailfin silverside fish in Lake Matano. Evol. Ecol. 24, 957–974. Pigeon, D., Chouinard, A. & Bernatchez, L. (1997). Multiple modes of speciation involved in the parallel evolution of sympatric morphotypes of Lake Whitefish (Coregonus clupeaformis, Salmonidae). Evolution 51, 196–205. Pinky, Mitta, S., Ojha, J. & Mittal, A. (2002). Scanning electron microscopic study of the structures associated with lips of an Indian hill stream fish Garra lamta (Cyprinidae, Cypriniformes). Eur. J. Morphol. 40, 161–169. Poléo, A.B.S. , Øxnevad, S. A., Østbye, K., Heibo, E., Andersen, R.A. & Vøllestad, L.A. (1995). Body morphology of crucian carp Carassius carassius in lakes with or without piscivorous fish. Ecography 18, 225–229. Rechulicz, J. & Kolejko, M. (2012).Morphological differences between lake and river populations of roach - Rutilus rutilus (L.). Ann. Univ. Mariae Curie-Sklodowska. Sect. EE Zootech. 30, 46–59. 20 Sagnes, P. & Statzner, B. (2009). Hydrodynamic abilities of riverine fish: a functional link between morphology and velocity use. Aquat. Living Resour. 22, 79–91. 21 Siwertsson, A., Knudsen, R., Adams, C.E., Præbel, K. & Amundsen, P.A. (2013). Parallel and non-parallel morphological divergence among foraging specialists in European 22 23 whitefish (Coregonus lavaretus). Ecol. Evol. 3, 1590–1602. Wu, C.I. (2001). Genes and speciation. J. Evol. Biol. 14, 889–89 Table S2 Chondrostom species plus control non-chondrostom cyprinid analyzed in this study with indication of sampling location. Species Achondrostoma oligolepis Chondrostoma angorense Chondrostoma nasus Chondrostoma vardarense Iberochondrostoma lemmingii Parachondrostoma toxostoma Protochondrostoma genei Pseudochondrostoma duriense Pseudochondrostoma polylepis Control Telestes souffia Basin River n Latitude Longitude Mondego Mondego Vouga Vouga Sankarya Loire Seine Aliakmon Guadiana Guadiana Quarteira Orbieu Rhône Tiber Tiber Douro Douro Douro Mondego Mondego Alva Anços Alfusqueiro Rio do Sul Yonëk Allier Chee Suran Assino Paglia Coa Tamega Paiva Alva Ceira 2 5 14 19 16 20 20 40 14 11 15 21 20 20 20 18 14 4 17 18 40°17′12.5″N 39°58′43.7″N 40°33′55.1″N 40°46′32.3″N 39°21′23″N 45°37'5.98"N 48°47'26.92"N 40°13'58"N 39°06'48.9"N 37°24'27.3"N 37°12'38.4"N 43°6'7.34"N 46°15'51.65"N 43°17'3.28"N 42°43'40.71"N 40°36'53.2"N 41°21'13.0"N 40°55'59.4"N 40°17′10.7″N 40°10′55.3″N 7°57′39.1″W 7°57′39.1″W 8°24′00.4″W 8°03′58.4″W 30°34′ 07″ E 3°12'41.69"E 4°49'10.471"E 21°58'15"E 7°16'35.1"W 7°45'36. 1"W 7°16'35.1"W 2°37'23.50"E 5°25'45.73"E 12°21'59.12"E 12°7'45.72"E 6°55'07.0"W 7°56'37.4"W 8°04'42.2"W 7°57′39. 1″W 8°21′04.7″W Rhône Rhône Durance Ardèche 8 17 44°26′54.113″N 4°18′31.283″E 44°28'32.54"N 4°15'48.94"E Caia Foupana