Ontogenetic changes in the feeding habits of the red gurnard Aspitrigla cuculus from the North-East Atlantic

• Main Author: Withecombe, Louise
• Other Authors: Faculty of Science
• Format: Thesis
• Language: English
• Published: 2004
• Subjects: North East Atlantic
• Online Access: http://hdl.handle.net/10026.2/2112

Ontogenetic changes in the feeding habits and dietary overlap of the red gurnard Aspitrigla cuculus inhabiting the waters of North-East Atlantic were investigated. The feeding ecology of red gurnard (Triglidae) has been well studied in the Mediterranean Sea but there has been little research carried out on the feeding behaviour of these species in British waters since the 1930’s. Further analysis of the dietary habits of red gurnard in British waters is needed to understand the ontogenetic and seasonal changes in prey choice exhibited by the species and understand the implications of commercial fisheries on these fish and their prey, This study revealed that ontogenetic shifts were present in diet composition, niche breadth and dietary overlap of the red gurnard Aspitrigla cuculus. Large red gurnard (>20cm) have a piscivorous diet and feed mainly on Callionymus lyra, whilst smaller gurnard prey predominantly upon benthic amphipods and carideans. Dietary overlap was highest between small red gurnard: (<14.9cm) and mid-sized red gurnard (15-19.9cm) with a significant overlap in diet of 0.75. Multivariate analyses also reveal ontogenetic shifts are present in the red gurnard’s diet with large red gurnard (>20cm) having significantly different feeding habits than the small (<14.9cm) and midsized sized (15-19.9cm) red gurnard. Temporal variation was observed in the feeding spectra of mid-sized red gurnard throughout the year. There has been a shift in the feeding behaviour of red gurnard between 1930 and 2004. The prey groups Galathea and Porcellana were the greatest contributors to the dissimilarity between dietary samples from 1930 and 2004.