Sperm bundles and phylogenesis

Structure and ultrastructure of spermatozoa of Chrysomya megacephala (Diptera: Calliphoridae)

“…For Aedes aegypti (Culicidae), it was suggested by Owusu-Daaku et al (2007), that the maximum number of spermatozoa per cyst for this species is probably 512, being the result of nine divisions from the original spermatocyst mother cell (stem cell), according to what has been proposed by Virkki (1969). In the RA mutant of C. capitata the number of germ line cells observed was constant, approximately 250 per cyst ( Báo and Dolder, 1990), the result of eight divisions.…”

“…According to Virkki (1969), archaic orders of insects have a greater number of sperm per bundle than recent orders, in other words, the most recent or specialized groups tend to have a smaller number of sperm per bundle.…”

Fine structural reconstruction on the testicular cyst of the furrow orb weaver,Larinioides cornutusby 3D volume rendering

“…As the number of divisions in a cyst appeared to be constant for a given species, the number of spermatids per cyst may be a characteristic trait for each species and can be expressed as 2 n (Virkki 1969;Phillips 1970). It is known that the number of sperm cells produced per cyst may lead to a better understanding of correlation between sperm number and sperm competition (Gomez Montono et al 2011).…”

“…Nevertheless, it seems that the number of sperms is interconnected with several traits during its lifespan including the difference in habitats and evolutionary consequences (Gomez Montono et al 2011;Tourmente et al 2011). Virkki (1969) suggested in insects that the more advanced orders and specialized groups are characterized by smaller number of sperms than the archaic or the less specialized groups. However, our findings obtained through serial researches among the familial levels of spiders do not seem to coincide with Virkki's proposal since a wandering lycosid spiders P. laura (Kim et al 2014) exhibited smaller number per cyst compared to a specialized group of web-building araneid spiders L. cornutus (Kim et al 2015).…”

“…When the exact number is known, the total number of sperm cells produced per cyst can be calculated accordingly (Virkki 1969). Understanding the exact number of sperm cells per cyst in spiders may be potentially useful in resolving various questions raised in many fields of spider biology, such as behavioral biology and ecology.…”