Meeting Abstract
Black perch are a common southern California reef fish. During breeding season, male black perch transfer a spermatophore (capsule containing spermatozoa) to the female via an intromittent organ during copulation. Females store the spermatozoa within the ovarian cavity until December when the eggs become fertilized and give live birth in May. The objective of our study was to describe the gonadal development of female and male black perch and describe the pathway of spermatophore transfer. Black perch were collected along the southern California coast. Gonadal tissues were dissected, preserved in Bouin’s fixative, and embedded in paraffin wax. Tissues were sectioned using a rotary microtome (5 µm thick) and analyzed. All female black perch had one developed ovary. Preliminary observations of the ovarian tissue from females < 150mm SL, had all stages of follicle development (primary, secondary, tertiary); no fertilized ova or embryos were present. In the fall, secondary follicles and fertilized ova were present in the ovarian tissue collected from females > 150mm SL. In spring, the ovarian cavity of females > 150mm SL contained 2-8 embryos 37.8 ± 4.1mm SL. In the fall, primary and secondary spermatocytes and spermatids were present within the testicular tissue of fish < 150mm SL. The intromittent organs on the anal fin consisted of a white patch with no external protrusion. In the fall, testicular tissue from males > 150mm SL contained all stages of spermatogenesis including spermatozoa and the development of spermatophores. The intromittent organs were enlarged and protruded from the anal fin. Males collected in spring are currently being analyzed and the pathway of spermatophore transfer is being determined. Histological analyses of gonadal development will aid in the understanding of reproduction in black perch.
