Largest of blennies is the Hairy Blenny -- Labrisomus nuchipinnis, around 6" long. A male sports bright courtship colors in this mating sequence. She inspects his crevice and responds to his display of credentials by wriggling out eggs for him to fertilize and guard.
After mating she will return to her relatively solitary life as a sit and wait style predator. "What Matters" by May Swenson:
'It may be that it doesn’t matter
who or what or why you love.
(Maybe it matters when, and for how long.)
Of course, what matters is how strong.
Maybe the forbidden, the unbelievable,
or what doesn’t respond –
what grabs and gives nothing –
what is ghoul or ghost,
what proves you a fool,
shrinks you, shortens your life,
if you love it, it doesn’t matter.
Only the love matters –
the stubbornness, or the helplessness.
At a certain chemical instant
in early youth, love’s trigger is cocked.
Whatever moves into focus
behind the cross hairs, magnifies,
is marked for target, injected with
magic shot. But the target doesn’t matter.' ~ "What Matters" by May Swenson
After mating he changes back to work-clothes-colors to tend and guard the eggs.
'We were like two fish in a pet store,
neighbors of separate plastic bags
destined for different homes;
i remember you looking back so sweetly.' ~ "Tanks in the Age of Aquariums"