Meeting Abstract
The caridean shrimp Lysmata wurdemanni is a protandric simultaneous hermaphrodite in which individuals go through a male phase before changing sex to female-phase simultaneous hermaphrodites. The latter have an externally female phenotype but retain a reduced male reproductive system and complete male and female reproductive function and behavior. Previously published studies reported that the androgenic glands, whose hormones stimulate development of male characteristics in decapod crustaceans, are absent in the female phase of purely protandric species. We tested the hypothesis of androgenic gland absence in simultaneous hermaphrodites of L. wurdemanni by dissection and histology on the ejaculatory ducts. These glands were observed in the simultaneous hermaphrodites although in a variably degraded form. Androgenic glands of L. wurdemanni male-phase individuals are compact and replete with well-developed cells with large, deeply staining nuclei, as in males of gonochoric and protandric species. The androgenic glands of simultaneous hermaphrodites were more reticulate in structure due to cell degeneration, resulting in vacuolization of the glands, but all possessed from numerous to at least some possibly functional cells. The greatest degeneration of the androgenic glands was observed in the largest (oldest) hermaphrodites. However, the ovotestes of all simultaneous hermaphrodites retained a small testicular portion with well-developed ejaculatory ducts containing sperm. Our results support but do not completely test the hypothesis that the reduced androgenic glands of L. wurdemanni female-phase simultaneous hermaphrodites accounts for their maintenance of male reproductive function after sex change.
