Tub Gurnard

• Its free pectoral rays carry taste receptors: it literally tastes the sand with its fingers as it walks in search of buried crustaceans.
• It produces audible grunts by contracting muscles against its swim bladder, a sound fishermen recognise as the nets come up.
• The brilliant blue of its pectorals, hidden while it swims, is flashed open as a warning signal at a predator.
• It walks along the seabed. The first three rays of each pectoral fin are free and modified into stiff appendages on which it props itself and steps across the sand.
• Those rays also carry chemoreceptors: they serve not only for walking but for tasting the bottom as it goes and locating buried prey.
• It produces sound with its swim bladder, which it vibrates with specialised muscles. The grunts are audible out of the water when it is landed, and this is the origin of the English name gurnard, from the French grogner, to grunt.
• Its spread pectoral fins are enormous and a deep blue with a bright edge: it flares them open suddenly as a warning.
• It migrates seasonally by depth: it gathers in shallow waters in spring and summer and moves deeper in winter.
• Until 2006 it was mostly discarded; since ICES recognised its commercial potential it has gained value at the fish market.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat & environment

Sandy and muddy bottoms of the eastern Atlantic and the Mediterranean, from 5 to 300 m

Sexual maturity

Size at first maturity 24.7 cm

Sources consulted: https://en.wikipedia.org/wiki/Tub_gurnard