6. RoU, quiver and gamete releG8e-The roll occurs simultaneously
with the firm clasp, placing the female in an upside down position with
her urogenital pore close to the nest. The male's position changes from
horizontal to an inverted U-shape over the female with his head pointed
downward. This places the male in a position to see the eggs as they
sink through the water. QuiverIng of the body and fins follows immediately
or occurs simultaneously with the roll. Egg release usually occurs
concurrently with and immediately after the roll although eggs are occasionally
released after the clasp terminates, and some were observed to
be discharged without a nuptial embrace