Does anyone have any advice about the following?

My supervisor, who is relatively unknown, takes credit for my work (informally and formally) at every available opportunity. When introducing himself to someone, he'll say that he is researching on my topic area without reference to me, i.e. 'I am exploring the impacts of X on Y'. He'll make no mention of my contribution to the work unless forced to. This happens in informal meetings but also on funding bids where the biography mentions my work as his own and similarly at conferences.

I've no idea what to do! Obviously, I know it's a two-way street. He's my supervisor so he can claim to be contributing to my work and has every right to benefit from the publications etc., which are produced. What worries me is that unless I'm always watching what happens, he sells my work as his own, with no mention of my existence!

Has anyone else had a similar experience?

Pre-empt his treachery by making sure you are the one who reports the work first to external audiences but don't be as deceitful as him, always make sure you say that he is your supervisor.

That is really tough. The same thing happened to me. I wrote an article for someone at a university (not my own and gosh am I tempted to name and shame in case anyone else ever googles him!) on the understanding that I would be named second author. He told me that though he would use my words he would not add me to the authorship as he still felt the article was his. a good 2000 words of his 6000 word article were taken from me verbatim. and there was nothing I could do.

but enough about me.

here you should think about mentioning your concern to someone else in the department, informally, and they may advise you as to whether you should have a quiet word with him, complain or something in between because they will know the terrain and personalities (and politics) better. you do need to do something, if nothing else than because if you look like your work is your supervisor's this may bite you in your viva. as well as being totally dispiriting. If dealing with it head-on puts you off, maybe indirect hits like requesting to change supervisors might help?

Most importantly you must do something. this could be the thin end of the wedge and you will have worked too hard for too long to let it slide.

good luck!