Arching effect on fish body shape in geometric morphometric studies
Abstract:Upward and downward arching of the body was observed during a study on redfishes Sebastes sp. population structure in the north-west Atlantic Ocean. The present study investigated the potential causes of this arching artefact. The results suggested that it is not related to biological factors (size or species) or to the preservation technique (freezing), but is rather due to slight posture differences between fishes during landmark capture. The consequences of the arching artefact on data analysis are discussed. An approach coupling a PCA-based model of the arching with Burnaby’s orthogonal projection is proposed for removing the artefact from the data.
Document Type: Regular Paper
Affiliations: 1: Museum National d’Histoire Naturelle de Paris, 55 rue Buffon, 75005, Paris, France 2: Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, 310, Allée des Ursulines, Rimouski (Québec) G5L 3A1 Canada 3: Direction des sciences halieutiques et aquaculture, Institut Maurice-Lamontagne, Ministère des Pêches et des Océans, 850 route de la Mer, C.P. 1000, Mont-Joli (Québec) G5H 3Z4 Canada 4: Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11794-5245, U.S.A.
Publication date: 2008-08-01