Tuesday, 15 October 2013

Have you seen a Corkwing wrasse nest?

Adult male Corkwing wrasse  photo Matt Slater 

The Corkwing wrasse Crenilabrus melops is one of the most colorful and interesting fish found in our coastal waters. When rockpooling (and Shoresearching) we often find juvenile corkwings hiding among sea weeds in large tide pools. When snorkeling we often see them busily swimming around but few people know about their fascinating nesting behavior. this June at Looe Bioblitz I was privileged to have Paul and Teresa Naylor and their son Sam join in with our rockpool ramble on the second day. Paul is a world renowned underwater photographer, author of 'Great British Marine Animals' and recently provided the photos for Teresa Naylors book 'Benny the Blennies Shallow Sea Adventure', all of which I thoroughly recommend you buy! visit  http://www.marinephoto.org.uk/ for more information.
Paul's passion is in studying the behavior of our marine creatures and his eagle eye was invaluable as he pointed out 2 corkwing wrasse nests. These nests are constructed in a deep rocky crevice on the low shore by the male wrasse and Paul tells me they carefully select the seaweeds they use to make the nest and build it up in layers - The heart of the nest being made of soft red seaweeds, an outer protective and breathable layer of scourweed (Ahnfeltia plicata)  and a top protective and camouflaging layer of Coral weed (Corallina officinalis) the construction must take weeks and the nests end up an impressive size a couple of feet wide and over 12 inches deep! An elaborate courtship display by the male entices one or more females to lay their eggs in the nest and the male then fertilizes them and covers the eggs with carefully selected seaweeds and guards them until they hatch. Once hatched the tiny corkwing wrasse fry then have to fend for themselves in the harsh  marine environment. Sometimes a tiny baby will be found when rockpooling but only a few will survive, to become adults.
When we returned to Hannafore point for our September Shoresearch survey the corkwing nests had all been washed away and it was surprising how deep the rocky crevice was that the nests had been constructed in - building a dense nest of this size is an incredible achievement for a single male corkwing wrasse!

Corkwing wrasse nest at Hannafore, Looe

juvenile wrasse photo Matt Slater

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