<font color='#000000'>Yup - these are nemaotde (sp?) worms common in all sorts of sea fish. They live in fish, eaten by predators (warm blooded ones) and then breed in the host, eggs crapped out, eaten by shrimps, which are eaten by fish and it all starts again.
Fairly easy to remove and killed by cooking - as long as you don't 'undercook' it as the trend is these days.
Rarely cause complications in humans I believe.</font>