title: Sperm dimorphism in the Triatoma brasiliensis species complex and its applications.
abstract: Morphological and structural features of the sperm of the Triatoma brasiliensis Neiva, 1911 (Hemiptera: Reduviidae) species complex were examined in this first study investigating the sperm of Heteroptera and the genus Triatoma. Males were dissected and their seminal vesicles removed. For measurement, seminal vesicles were squashed on glass slides, spread, fixed and observed under a photomicroscope. The images were analysed and measures of sperm were made. Data were analysed using one-way analysis of variance and Tukey's test to detect differentiation among taxa. Furthermore, seminal vesicles were prepared for studies of transmission electron microscopy. All taxa studied showed polymorphic (short and long) sperm. The sperm of Triatoma brasiliensis macromelasoma was significantly longer (in total length) than that of the other four members of the complex, which supports the hypothesis of hybrid speciation of this member of the complex as an increase in the size of typical hybrids under heterosis was previously shown. The sperm cells of the five taxa have similar ultrastructural morphology. The ultrastructural features observed confirm the hypothesis, raised by previous studies, that they are synapomorphic to the suborder Heteroptera.
authors.affiliation: Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.|Laboratório de Insetos Aquáticos, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: A F
authors.initials: AF
authors.lastname: Baffa
authors.affiliation: Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.
authors.forename: D C P
authors.initials: DCP
authors.lastname: Camara
authors.affiliation: Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.
authors.forename: J R
authors.initials: JR
authors.lastname: Santos-Mallet
authors.affiliation: Laboratório de Insetos Aquáticos, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: E R
authors.initials: ER
authors.lastname: DA Silva
authors.affiliation: Laboratório de Biodiversidade Entomológica, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Costa
authors.affiliation: Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.
authors.forename: S P C
authors.initials: SPC
authors.lastname: Freitas
mesh_terms: D000818:Animals; D007303:Insect Vectors / Q000145:classification* / Q000648:ultrastructure*; D008297:Male; D046529:Microscopy, Electron, Transmission; D013094:Spermatozoa / Q000648:ultrastructure; D014224:Triatoma / Q000145:classification* / Q000648:ultrastructure*
keywords: Heteroptera; insect vector; male reproductive system; reproduction