Use of the otolith shape analysis in stock identification of anglerfish (Lophius piscatorius) in the Northeast Atlantic

Abstract

Cañás, L., Stransky, C., Schlickeisen, J., Sampedro, M. P., and Fariña, A. C. 2012. Use of the otolith shape analysis in stock identification of anglerfish (Lophius piscatorius) in the Northeast Atlantic. – ICES Journal of Marine Science, 69: 250–256. The geographical variability in the anglerfish Lophius piscatorius otolith shape was investigated to examine biological evidence for the current separation into Northern and Southern stocks of L. piscatorius established in the Southwest European waters (Southern Shelf area) by the International Council for the Exploration of the Sea (ICES). In all, 629 otoliths of L. piscatorius (12–90 cm total length) from commercial fishing and research surveys were collected in two consecutive years, 2008 and 2009. The otolith shape was compared between stocks for differences in univariate descriptors using non-parametric analysis of covariance, as well as elliptical Fourier shape descriptors, through a metric multidimensional scaling and a linear discriminant analysis (LDA). The differences found in the otolith shape between Northern and Southern stocks were not large enough to hold the current status of L. piscatorius regarding stock definition in the Southern Shelf area, although homogeneous mixing between both stocks is not expected as there were significant differences between three univariate descriptors and the LDA was significant. These results are in agreement with the previous L. piscatorius stock identification studies (genetics, body morphology, and migratory behaviour), which do not support the current separation of these stocks but found substructures within the area.

Otolith Sr:Ca ratio and morphometry as indicators of habitat of a euryhaline species: The case of the silverside Odontesthes bonariensis

“…Other approaches such as the analysis of otolith morphology and morphometry have been widely used to differentiate fish stocks (Longmore 2010, Cañás et al 2012, Keating et al 2014, and even to identify existing species (Tuset et al 2013, Zhuang et al 2014 or fossilized fish (Reichenbacher et al 2009, Reichenbacher andReichard 2014); however, only a few studies relate morphometric variables to different environments or ecomorphological patterns (Nelson et al 1994;Volpedo and Fuchs 2010;Avigliano et al 2012Avigliano et al , 2014.…”

“…Otra herramienta ampliamente utilizada para la determinación de poblaciones pesqueras es la morfometría del otolito (e.g., Longmore et al 2010, Cañás et al 2012, Keating et al 2014. El análisis de la morfometría de los otolitos permite generar una descripción cuantitativa de la forma y el contorno que puede compararse estadísticamente (Lestrel 1997).…”

“…El análisis de la morfometría de los otolitos permite generar una descripción cuantitativa de la forma y el contorno que puede compararse estadísticamente (Lestrel 1997). Entre los índices morfométricos más utilizados están la circularidad, rectangularidad, elipticidad, factor de forma y área del sulcus/área del otolito (e.g., Volpedo et al 2008, Longmore et al 2010, Cañás et al 2012, Tuset et al 2013. De hecho, ambas metodologías se han usado conjuntamente en estudios recientes (e.g., Longmore et al 2010.…”

“…Otolith morphometrics are also used to identify fish stocks (e.g., Longmore et al 2010, Cañás et al 2012, Keating et al 2014. The morphometric analysis of otoliths permits a quantitative description of the shape and contour that can be statistically compared (Lestrel 1997).…”

“…The morphometric analysis of otoliths permits a quantitative description of the shape and contour that can be statistically compared (Lestrel 1997). Some of the most commonly used shape indices are circularity, rectangularity, ellipticity, form factor, and sulcus area/otolith area (e.g., Volpedo et al 2008, Longmore et al 2010, Cañás et al 2012, Tuset et al 2013. In recent studies, both methods have been used (e.g., Longmore et al 2010.…”