Egg or larvae collections and fry rearing
Observation of females to detect those carrying egg clutches was
carried out daily and eggs were removed immediately from such
females. The clutch was removed by netting the female, opening its
mouth gently and allowing eggs or larvae to drop into a pail of water.
The PIT-tag number of the female was recorded prior to returning it to
the experimental tank. Eggs were then transferred into downwelling
incubators until they hatched and the fry had absorbed the yolk sac.
Batches of fry were grown on until at least 3 weeks post-hatch
(approximately 15 mm in total length) for clear scoring of colour (red
or wild type). Batches of fry where b10 fry survived to this stage were
eliminated from the dataset.