A place for nourishment or a slaughterhouse? Elucidating the role of spermathecae in the terrestrial annelid Hormogaster elisae (Clitellata: Opisthopora: Hormogastridae)

作者：Novo Marta^*; Riesgo Ana; Roldan Carmen; Giribet Gonzalo; Diaz Cosin Dario J

来源：Zoomorphology, 2012, 131(2): 171-184.

DOI：10.1007/s00435-012-0151-6

• Annelida
• Opisthopora
• Spermathecae
• Spermatozoa
• Sperm digestion
• Transmission electron microscopy
• Secretions

The capacity of storing sperm within the female reproductive tract occurs widely across vertebrate and invertebrate species. Although the type and position of spermathecae have been commonly used as a taxonomic character in Opisthopora, few studies have focused on the ultrastructural description of these interesting storage organs. This study is the first to report on the ultrastructure of the spermathecae and spermatozoa of Hormogaster elisae, an endemism of the central area of the Iberian Peninsula that presents two pairs of tubular spermathecae. Light and electron microscopy showed that the spermathecae are full of highly packed spermatozoa embedded in an electron-dense substance. Two layers constitute the spermathecal wall. The outer layer consists of peritoneal cells, collagenous basal laminae at different levels, several layers of striated muscle, and numerous blood vessels. The inner layer is a monostratified epithelium of prismatic cells presenting long and abundant microvilli probably for the maintenance of a favorable environment for the spermatozoa. The epithelial cells show high activity, and three different types of secretions were detected: holocrine, merocrine, and apocrine, whose hypothetical function on nourishment and/or causing quiescence is discussed here. Although no phagocytotic processes were detected, some sperm cells were observed in digestive vesicles within the cytoplasm of the epithelial cells, and there was also evidence of active sperm entrance into the epithelium. A place for nourishment or a slaughterhouse? Probably both.

• 出版日期2012-6