TY - JOUR
T1 - Pediculus humanus capitis
T2 - a study of the male genitalia using a combined stereoscopic, confocal laser scanning, and scanning electron microscopy approach
AU - Álvarez-Fernández, Blanca E.
AU - Morales-Suárez-Varela, María
AU - Nogueda-Torres, Benjamín
AU - Valero, M. Adela
N1 - Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - Background: The male genital structures of arthropods are key features in the taxonomic and phylogenetic study of these organisms. The male genitalia of the head louse Pediculus humanus capitis are complex organs which are partly composed of structures that dynamically extrude during copulation. Methods: Here, we describe the morphology of the genitalia of P. humanus capitis at the copulation stage, and at rest, by using stereoscopic microscopy, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM). Results: CLSM and SEM images revealed that the vesica is composed of two distinct anatomical parts, the proximal lobe and the distal lobe. Both lobes have short and narrow spines, as well as long and wide scales with either sharp or rounded tips. The rounded scales vary in size and have a wavy base and rounded tips, and thus resemble a tongue in appearance. We identified a gland-like area on the penis with 11 shallow circular depressions, and a flat area with 14–16 exit orifices. The apical end of the penis has a foliaceous trifurcation and serves to expel the contents of the ejaculatory duct. These characteristics were recorded for all the specimens analyzed, indicating that these structures are highly conserved; to our knowledge, they have not been previously reported for any suborder of lice. Conclusions: To the best of our knowledge, our results reveal for the first time the morphological details, and complexity, of the male genitalia of the head louse P. humanus capitis at different stages of copulation. The new approach described here provided information that should be taken into consideration in future research on the genitalia of lice. Application of this approach will also impact the taxonomic and phylogenetic study of other insect taxa. Graphical Abstract: [Figure not available: see fulltext.].
AB - Background: The male genital structures of arthropods are key features in the taxonomic and phylogenetic study of these organisms. The male genitalia of the head louse Pediculus humanus capitis are complex organs which are partly composed of structures that dynamically extrude during copulation. Methods: Here, we describe the morphology of the genitalia of P. humanus capitis at the copulation stage, and at rest, by using stereoscopic microscopy, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM). Results: CLSM and SEM images revealed that the vesica is composed of two distinct anatomical parts, the proximal lobe and the distal lobe. Both lobes have short and narrow spines, as well as long and wide scales with either sharp or rounded tips. The rounded scales vary in size and have a wavy base and rounded tips, and thus resemble a tongue in appearance. We identified a gland-like area on the penis with 11 shallow circular depressions, and a flat area with 14–16 exit orifices. The apical end of the penis has a foliaceous trifurcation and serves to expel the contents of the ejaculatory duct. These characteristics were recorded for all the specimens analyzed, indicating that these structures are highly conserved; to our knowledge, they have not been previously reported for any suborder of lice. Conclusions: To the best of our knowledge, our results reveal for the first time the morphological details, and complexity, of the male genitalia of the head louse P. humanus capitis at different stages of copulation. The new approach described here provided information that should be taken into consideration in future research on the genitalia of lice. Application of this approach will also impact the taxonomic and phylogenetic study of other insect taxa. Graphical Abstract: [Figure not available: see fulltext.].
KW - Confocal laser scanning microscopy
KW - Copulation
KW - Dilator
KW - Genital chamber
KW - Genitalia
KW - Pediculus humanus capitis
KW - Scanning electron microscopy
KW - Vesica
UR - http://www.scopus.com/inward/record.url?scp=85119284989&partnerID=8YFLogxK
U2 - 10.1186/s13071-021-05082-w
DO - 10.1186/s13071-021-05082-w
M3 - Artículo
C2 - 34789330
AN - SCOPUS:85119284989
SN - 1756-3305
VL - 14
JO - Parasites and Vectors
JF - Parasites and Vectors
IS - 1
M1 - 577
ER -