Sexual Differentiation in Juvenile American Lobster (Homarus americanus)

American lobsters (Homarus americanus (H. Milne Edwards, 1837)) settling to the bottom after their pelagic larval stage are sexually undifferentiated. Based on stereomicroscope observations, the femaleâ s gonopore first appeared for lobsters about 13 mm carapace length (CL), and the dimorphism of the first pair of male pleopods was first observed at about 15 mm CL. Based on histological observations, the internal reproductive system for both males and females began differentiating at sizes â Ľ 20 mm CL. The vasa deferentia were observed for males > 30 mm CL indicating that the male reproductive system is fully formed. For females, the ovaries were observed at sizes â Ľ 20 mm CL but the oviducts were not detected in animalsThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author