Feeding Habits and Diet Overlap of Skates (Amblyraja radiata, A. hyperborea, Bathyraja spinicauda, Malacoraja senta and Rajella fyllae) in the North Atlantic

• Main Authors: González-Iglesias, M.C. (María de la Concepción), Román-Marcote, E. (Esther), Paz, X. (Xabier), Ceballos, E. (Elvira)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Centro Oceanográfico de Vigo 2006
• Subjects: Arctic; Bathyraja spinicauda; North Atlantic; Northeast Atlantic; Northwest Atlantic
• Online Access: http://hdl.handle.net/10508/692

The contents of 5061 stomach of five skate species -thorny (Amblyraja radiata), Arctic (A. hyperborea), spinytail (Bathyraja spinicauda), smooth (Malacoraja senta) and round skates (Rajella fyllae) obtained from Spanish Bottom Trawl Research Surveys in northwest and northeast Atlantic (NAFO, Divisions 3NO and Div. 3M; ICES, Div. IIb) in the period 1996-2005 were analyzed to study the feeding intensity and food habits. Feeding intensity was high in all skate species and areas, slightly higher in Div. IIb, showing a general trend to decrease according to the predator size increase. Importance of prey was based in weight percentage. The main prey groups for thorny and Arctic skates were Pisces and Crustacea, but the importance of each group and prey species changed with area. Pisces has turn out to be the dominant prey taxa for spinytail skate in Div. 3NO and 3M. Crustacea have been the dominant prey group for smooth skate. Round skate has changed its main prey group in each area, but polychaetes have been prominent in Div. 3NO. Predation on fishing processed remnant was important for Arctic skate. Predation on several species of commercial importance was mainly relevant in Div. 3M. Intra-specific diet overlap showed a different pattern varying with skate species and area. Inter-specific diet overlap reached its highest level in the Arctic area. Thorny skate showed a high diet overlap with the majority of the skate species studied in the NAFO Area, and round skate did not show diet overlap with other skate species in Div. 3NO. Thorny skate appear as dominant predator in NAFO Div. 3NO.