Sea Squirts:  Sperm Warfare

Life under the waves can get pretty crowded when you are a sea squirt vying for space on the rocks. But these sea creatures have a novel weapon--they use their sperm to sabotage the eggs of other kinds of sea squirt. According to a marine biologist in California, this may be the first example of sperm competition between species.(Extract from the New Scientist)

Some classification notes

Tunicate Mailbase EForum
http://www.jiscmail.ac.uk/lists/tunicata/
 

Sea Squirts are fouling organisms on wharves and piers Ciona intestinalis

Lightbulb Sea Squirt, Clavelina lepadiformis

News Reports
 

30 August 2005
Three visiting marine biologists found the invasive ascidian Corella eumyota in St. Peter Port Harbour, Guernsey, Channel Islands. This southern hemisphere sea-squirt was first discovered in Europe in Brittany in 2002.  It has now been found in marinas along the south coast of England and also along the Channel coast of France.
 

Corella eumyota

Whilst accompanying the biologists in St. Peter Port Harbour, I found many Goniodoris castanea sea slugs with their spawn. They were feeding on the colonial Star Ascidian, Botryllus schlosseri,  and were cryptic.  On one 5 x 5 cm
square colony of Botryllus schlosseri I found six of these nudibranchs. Dr. Charles David, President of La Société Guernesiaise, tells me this species is a new record for Guernsey.