A view of the hectocotylized arm of a male O. briareus moving into the mantle cavity of the female. The males arm is the narrow dark colored arm going up then back down into the opening of the mantle cavity of the female. The spermatophoric groove along the males arm is clearly seen in this view.
Caitlin, this image is upside down and needs to be flipped over so my caption reads right.
Maturity: Adult; Sex: Male, female; Lab or Wild: Lab; Origin: Caribbean sea