Pair of Red Mullet feeding in Plymouth Sound
Despite their names , these fish are unrelated . However , when I started to think about including them in this month ’ s column , I realised that , when it came to meeting them underwater , they have an appealing feature in common . If you manage to spot them from a few metres away and then approach carefully without spooking them , you can watch them seeking out their food in their different and very characteristic ways .
The red mullet is often prettily coloured , typically with a bold reddish stripe down the body and a variable variety of orange and yellow patches . It has obvious large scales , a steep forehead and , most distinctive of all , a pair of long white barbels or ‘ feelers ’ on its chin , with which it searches for food . If you manage not to spook the red mullet , you can see them swim busily along , constantly probing the seabed with their barbels . A cloud of silt may then suddenly erupt around them as they locate something tasty , presumably a small invertebrate , and dig down to get it .
Other fish such as dragonets and particularly wrasse regularly follow red mullet and lurk where they can observe what is being found . I have yet to see one of the lurking fish get a free meal , but they must sometimes benefit , or why do they do it ? We occasionally see single red mullet but it is much more common to find them in pairs or groups . In one memorable sighting , before I started carrying a camera ( even just a small one ) on every dive , I saw a shoal of at least 50 browsing on the sand near the well-known Louis Shied wreck at Thurlestone in South Devon .
The frustration of disturbing red mullet and seeing them disappear into the gloom is often offset by watching how a group seems to take its cue from the most nervous members signalling danger by raising their boldly striped front dorsal fin .
I find grey mullet much shyer and harder to approach . Given how often I see them in the shallows at the start or end of a shore dive , I have amazingly few usable photographs . They have a torpedo-shaped silver-grey body , with visible stripes down their flanks if you get close enough . They feed mainly by grazing head-down over the seabed , using their small , pursed mouths to hoover up sediment . The resulting muddy mouthfuls are then filtered with large gills and processed in a long intestine to extract nutrition .
You can also see them using their rubbery-looking lips to scrape off the slimy algae from large seaweeds , rocks and even mooring ropes and pontoons . On one dive at Porthkerris in Cornwall ( an excellent fish-watching location ) I
Two Red Mullet searching for food , with a Dragonet lurking nearby
saw a group simply gulping at the water where the plankton was thick . As there are three species of grey mullet in our waters , their identification is less certain . Most commonly seen are thicklip grey mullet ( Chelon labrosus ) but there are two similar species : the thinlip grey mullet ( C . ramada ) and the golden grey mullet ( C . auratus ). �
Paul ’ s photos and video clips capturing UK marine life stories are on Instagram @ paulnaylormarinephoto
" Other fish such as dragonets and particularly wrasse regularly follow red mullet "
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