Nice blue ! Male breeding suit on. They shuffel a hollow in the sandy bottom in up to about 2m of water where the eggs are layed in and the parients protect the eggs. Once they breed out the small are swallowed by the parients when danger lumes, then spit out when all is safe. If you wade carefully you can sometimes see the cloud in front of the blue which disappears when she sense danger.
While the blues are guarding the nest, they will attack intruder buggs like spinners, lead head and curly tail as well as attack other fish like barbel even if the other fish is a lot larger than themself, so they are very agressive during this time.
Nice sports if you catch them on 4lb line, especially those 2kg jobbies.