Unraveling post-copulatory sexual selection mechanisms in cephalopods: morphology of the squid's seminal receptacle applying confocal microscopy and 3D reconstruction

Abstract

Sexual selection has a crucial role in the evolution of reproductive traits. Males use several strategies to ensure fertilization, but females also play a major role in pre and post-copulatory processes. Cephalopods transfer sperm packed within spermatophores, and in some cases females bear specialized organs for sperm storage (i.e., seminal receptacles). However, the morphology of these organs and their functioning (e.g., sperm uptake, storage and release by the seminal receptacles) remain poorly known. In recent years, integrative microscopy techniques have increasingly been applied to morphology investigations. Particularly, specialized micromorphological tools, such as Confocal Scanning Laser Microscopy and 3D reconstruction, revealed to be very insightful for anatomical purposes. Based on this scenario, this project aims at investigating the muscular and nerve system associated with the squid seminal receptacle, using a model organism (Doryteuthis plei) and applying Confocal Laser Scanning Microscopy. This proposal is a complement of an ongoing MSc thesis that is applying light and electron microscopy techniques to better understand the functioning of this organ, and its role in capture and storage of sperm, as a basis for understanding post-copulatory sexual selection mechanisms in cephalopods. (AU)