1991/05/01 by Philip L. Miller · 39 citations
Biochemistry, Genetics and Molecular Biology · Environmental Science · #Lepidoptera: Biology and Taxonomy #Freshwater macroinvertebrate diversity and ecology #Ecology and Vegetation Dynamics Studies #Biology #Penis #Sperm #Sperm competition #Anatomy #Female sperm storage #Flagellum #Odonata #Zoology #Sexual selection #Paleontology #Botany
paper · doi:10.1111/j.1096-3642.1991.tb01536.x
published in Zoological Journal of the Linnean Society 102(1), 43-73 (Oxford University Press)
openalex publication_date 1991/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/11
An outline of the morphology of the secondary genitalia of libellulid dragonflies is given together with a more detailed treatment of the components of the fourth (distal) segment of the penis. The variations of penis structure in 70 species, representing ten of the 11 subfamilies, are surveyed and catalogued. There is remarkable diversity in the presence and form of penis structures, particularly those associated with the medial process, namely the flagelium, cornua and inner lobes. A comparable survey of females shows that they can be provisionally divided into ten types according to the number and size of their sperm-storage organs. Comparisons of penis structures with the sperm-storage organs of females suggests that in species whose females store large amounts of sperm, usually doing so in one or a pair of organs, males possess highly extensible, lobate and bristly penes, commonly equipped with cornua. By contrast, in those species in which the females store small volumes of sperm, usually doing so in three organs, the penes bear either flagella equipped with proximally directed spines or with large terminal barbs, or they have narrow, spiny inner-lobes which resemble flagella. Some functional interpretations are proposed in the light of sperm competition. The variability of genital structure can be interpreted adaptively and does not closely reflect phylogenetic relationships. Functionally convergent structures have evolved a number of times from different origins.