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.

Sperm ultrastructure of Pycnoderes incurvus (Hemiptera: Miridae)

“…The infraorder Cimicomorpha comprises 17 families, Miridae being the most specious, with more than 11,000 species (Weirauch & Schuh, 2011). However, only Reduviidae, Cimicidae and Anthocoridae had the sperm ultrastructure studied (Baffa et al, 2017; Báo & De Souza, 1994; Dallai & Afzelius, 1980; de Oliveira et al, 2019; Dolder, 1988; Santos & Lino‐Neto, 2018). The sperm of Pycnoderes incurvus (Bryocorinae) was previously described using light microscopy by Rezende et al (2021), which showed some interesting features worth further investigation (Figure 1).…”

Chitin Biosynthesis Inhibitors in Euschistus heros Fabr. (Hemiptera: Pentatomidae): Morphometric Alterations in Testes and Nuclei of Testicular Accessory Cells of Adults

“…In Heteroptera, many works that assess the morphology and morphometry parameters studied on the germ line cells, with a major focus on the spermatogenesis final processes (Araújo, Lino-Neto, Ramalho, Zanuncio, & Serrão, 2011;Araújo, Báo, & Lino-Neto, 2012;Baffa et al, 2017;Novais, Dias, & Lino-Neto, 2017;Santos & Lino-Neto, 2018). However, none of them presents focus in the TACs morphometry.…”