The morphology of black perch intromittent organs is similar to the striped (Embiotoca lateralis) and pile perches (Damalichthys vacca; Blake 1868; pers.
Additionally, we have characterized the tissues of the intromittent organs and its muscular sheath which reside on an unmodified anal fin.
A) Anal fin of black perch < 90 mm SL; white circle represents location of developing intromittent organ and surrounding sheath; B) Anal fin of black perch [greater than or equal to] 90 mm SL indicating the surrounding sheath that houses the intromittent organ.
IO = intromittent organ; DCT = dense connective tissue; LCT = loose connective tissue; FR = fin ray.
A) Micrograph of the anal fin (4X); B) Circular smooth muscle (20X); C) Longitudinal smooth muscle and dense fibrous connective tissue (20X); D) Intromittent organ (20X); E) Fin rays and dense fibrous connective tissue (20X).