Research Document - 2013/085

Morphometric and meristic variability of wolffish (Anarhichas sp.) in Newfoundland and Labrador waters

By M.R. Simpson, L.G.S. Mello, and C.M. Miri

Abstract

Morphological variation within Northern Wolffish (Anarhichas denticulatus), Spotted Wolffish (A. minor), and Atlantic Wolffish (A. lupus) in Newfoundland and Labrador continental shelf waters were examined, and observed patterns utilized as a basis for delineating distinct groups of wolffish in the study area. A total of 1,425 specimens (136 Northern Wolffish; 244 Spotted Wolffish; 1,045 Atlantic Wolffish) collected during Fisheries and Oceans Canada Newfoundland and Labrador Region (DFO-NL) research surveys in the Northwest Atlantic Fisheries Organization (NAFO) Div. 2HJ3KLMNO and Subdiv. 3Ps were sampled for standard morphometric and meristic characteristics. Principal Component Analysis (PCA) explained between 74-79% and 84-88% of the variance in morphometric and meristic measurements, respectively. Bivariate plots of Principal Components (PC) exhibited patterns of variation in morphometric characteristics of Northern Wolffish, and in morphometric and meristic characteristics of Atlantic Wolffish from different areas.

Based on this analysis, it appeared that Northern Wolffish comprise at least two distinct groups in NL waters: a southern group centered on the northern and southeastern Grand Bank (Div. 3LN), and another smaller group scattered over much of the northeast Newfoundland (Div. 3K) and Labrador shelves (Div. 2J). For Atlantic Wolffish, it also appeared that there are two distinct groups: one centered on the southern Labrador shelf (Div. 2J); and another group centered on the southwest Grand Bank (Div. 3O). Atlantic Wolffish from Div. 3KLN and Subdiv. 3Ps were neither morphometrically nor meristically distinguishable from the other two groups of this species. This study provides potentially useful evidence for delineating boundaries of different groups of Northern Wolffish and Atlantic Wolffish in Newfoundland and Labrador waters.

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