Research has shown that Ballan wrasse are protogynous hermaphrodites,
that is the are all born female and only first change sex to males when
conditions allow. Males are territorial only when eggs are guarded. The
rest of the time they are homerangeing keeping mostly to one area of 100-400
Ballan wrasse grow very old 30 years is not uncommon. They can be very shy, but scubadivers can easily tame them to take food from divers when offered.
The goldsinny has smaller spawning territories than ballan wrasse and
do not guard eggs. They are shed directly into the water pelagically (actually
floating?). Territory is kept only during the spawning period.
In Norway wrasse have been captured in very large numbers to work in salmon penns. The results are fantastic. The problems associated with their use have been high mortality rates and issues regarding liveing in a net versus along the bottom.
This is especially apparent during the winter when wrasse seak deeper water to overwinter. High mortality resulted before the wrasse were collected and lowered into deeper water.
Lately ballanwrasse have been reared and found to be the perfect cleaner fish. They are introduced as cleaners 1 year old with smolt salmon. The second year they are just large enough not to be eaten by the larger salmon. This is also thought to reduce the strain on natural populations.
Surveys done here in Norway suggest that there is a marked decline in natural populations of some species due to fishing.
Especially ballan and corkwing. Due to their shorter lifespand and fast maturity goldsinny are still surviving in good numbers.
Remeber though that Norway has a lot more wrasse than the British isles and the effect thus is thought to be much smaller than a similar strain on British populations.