BACKGROUND: The impressive diversity in the feeding apparatus often seen among related fish species clearly reflects differences in feeding modes and habitat utilization. Such variation can also be found within species. One example of such intraspecific diversity is the Arctic charr in Lake Thingvallavatn, where four distinct morphs coexist: two limnetic, with evenly protruding jaws, and two benthic, with subterminal lower jaws. We used these recently evolved morphs to study the role of ontogenetic variation in shaping craniofacial diversity. RESULTS: The segmental development of the pharyngeal arches and the order of events in craniofacial development is the same as has been described for teleosts, emphasizing the conserved nature of this process. However, our morphometric analyses reveal differences between morphs. Hatching is accompanied by increase in size and allometric shape changes in Arctic charr. Ontogenetic trajectories of craniofacial shape also differ significantly between morphs. CONCLUSIONS: The results point to hatching as a significant developmental event in Arctic charr and possibly other fishes. Also, the developmental origins of limnetic and benthic specializations in the craniofacial elements of Arctic charr may stem from events around hatching. This calls for investigations of the mechanisms and consequences of hatching, in the context of development and evolution. Developmental Dynamics 244:1168-1178, 2015.
BACKGROUND: The impressive diversity in the feeding apparatus often seen among related fish species clearly reflects differences in feeding modes and habitat utilization. Such variation can also be found within species. One example of such intraspecific diversity is the Arctic charr in Lake Thingvallavatn, where four distinct morphs coexist: two limnetic, with evenly protruding jaws, and two benthic, with subterminal lower jaws. We used these recently evolved morphs to study the role of ontogenetic variation in shaping craniofacial diversity. RESULTS: The segmental development of the pharyngeal arches and the order of events in craniofacial development is the same as has been described for teleosts, emphasizing the conserved nature of this process. However, our morphometric analyses reveal differences between morphs. Hatching is accompanied by increase in size and allometric shape changes in Arctic charr. Ontogenetic trajectories of craniofacial shape also differ significantly between morphs. CONCLUSIONS: The results point to hatching as a significant developmental event in Arctic charr and possibly other fishes. Also, the developmental origins of limnetic and benthic specializations in the craniofacial elements of Arctic charr may stem from events around hatching. This calls for investigations of the mechanisms and consequences of hatching, in the context of development and evolution. Developmental Dynamics 244:1168-1178, 2015.
Authors: Johannes Gudbrandsson; Ehsan P Ahi; Sigridur R Franzdottir; Kalina H Kapralova; Bjarni K Kristjansson; S Sophie Steinhaeuser; Valerie H Maier; Isak M Johannesson; Sigurdur S Snorrason; Zophonias O Jonsson; Arnar Palsson Journal: F1000Res Date: 2015-06-01
Authors: Skúli Skúlason; Kevin J Parsons; Richard Svanbäck; Katja Räsänen; Moira M Ferguson; Colin E Adams; Per-Arne Amundsen; Pia Bartels; Colin W Bean; Janette W Boughman; Göran Englund; Jóhannes Guðbrandsson; Oliver E Hooker; Alan G Hudson; Kimmo K Kahilainen; Rune Knudsen; Bjarni K Kristjánsson; Camille A-L Leblanc; Zophonías Jónsson; Gunnar Öhlund; Carl Smith; Sigurður S Snorrason Journal: Biol Rev Camb Philos Soc Date: 2019-06-19
Authors: Ehsan Pashay Ahi; Sophie S Steinhäuser; Arnar Pálsson; Sigrídur Rut Franzdóttir; Sigurdur S Snorrason; Valerie H Maier; Zophonías O Jónsson Journal: Evodevo Date: 2015-09-16 Impact factor: 2.250
Authors: Samantha V Beck; Katja Räsänen; Ehsan P Ahi; Bjarni K Kristjánsson; Skúli Skúlason; Zophonías O Jónsson; Camille A Leblanc Journal: Evol Dev Date: 2018-11-26 Impact factor: 2.839