Ultrastructure and heteromorphism of spermatozoa in five species of bugs (Pentatomidae: Heteroptera)

Abstract

Pentatomidae is one of the largest Heteroptera families, comprising about 10% of the species estimated for the suborder. In spite of existing studies, doubts remain regarding the systematics of Pentatomomorpha. In this study, five species of Pentatomidae spermatozoa were examined to achieve characteristics that enable inferences in the phylogeny of the group and in behavioral issues associated with the presence of polymorphisms. Spermatozoa polymorphisms, characterized by two classes of sizes, are found in Podisus nigrispinus, Podisus distinctus, and Brontocoris tabidus, whereas Thynacanta marginata (Dallas) and Supputius cincticeps have single-size spermatozoa. The head region consists of an acrosome, a nucleus, and part of the centriolar adjunct. In the more anterior region, the nucleus is parallel to the centriolar adjunct. In the nucleus-flagellum transition region, the nucleus overlaps the anterior region of the mitochondrial derivatives, just above the axoneme. The mitochondrial derivatives and the axoneme run the entire extent of the flagellum. In species in which the spermatozoa are polymorphic, the larger spermatozoa have derivatives mitochondrial approximately 3-fold larger than the smaller spermatozoa. Characteristics derived from the morphology of spermatozoa indicate synapomorphies and are promising for systematic studies.

Sperm dimorphism in the Triatoma brasiliensis species complex and its applications

“…The production of more than one type of sperm by the same male, as observed in the T. brasiliensis species complex and in other Hemiptera (Kubo‐Irie et al ., ; Chawanji et al ., , ; Araújo et al ., , ) is attributable to differences in total and nuclear lengths. However, the total lengths of the short and long sperm of the T. brasiliensis species complex are larger than previously described in Hemiptera (Báo & De Souza, ; Kubo‐Irie et al ., ; Araújo et al ., ). Although T. b. brasiliensis and T. b. macromelasoma may be considered the most intimately related of the T. brasiliensis complex, this study shows that both can be differentiated by their sperm length.…”

Lightweight males of Podisus nigrispinus (Heteroptera: Pentatomidae) neglect lightweight females due low reproductive fitness

“…The production of polymorphic sexual cells by P. nigrispinus males might have distinct functions, such as fertilization, nutrition and competition (Araújo et al, 2011). This indicates that the embryos might have components used for parental nutrition (for example) and for maintaining high viabilities.…”

“…Longer copulations by P. nigrispinus were attributed to the protracted movement of the aedeagus to reach the spermatheca and release the sperm, rather than the length of copulation acting as a guarding behavior (Rodrigues et al, 2008). However, the production of polymorphic sexual cells by P. nigrispinus males suggests that there are distinct functions to these cells and indicates the evolutionary importance of intrasexual competition (Araújo et al, 2011).…”

Seven decades of studies with Asopinae predators in Brazil (1933●-○2014)

“…Studies on the possibility of mating (copulation duration and successive copulations) provide morphological changes of the spermatheca and ducts showed that the spermatheca of Asopinae presented elastic characteristics and that the ducts were not affected ("swollen") after 30 min copulations (RODRIGUES et al, 2008). Morphology of the spermatozoa of Asopinae was observed and results may help systematists and taxonomists identify insects of this group (ARAÚJO et al, 2011).…”