Morphology of the male reproductive system and spermatozoa of Smicridea (Rhyacophylax) iguazu Flint, 1983 (Trichoptera, Hydropsychidae).

The Trichoptera, holometabolous aquatic insects found worldwide except in Antarctica, exhibit a unique feature in their sperm, which are solely nucleated (eupyrene). Current knowledge on Trichoptera sperm is limited to Old World species. To enhance our understanding of their reproductive biology and contribute to systematic discussions, we describe the male reproductive system and spermatozoa of Smicridea (Rhyacophylax) iguazu Flint, 1983 (Hydropsychidae). This species lacks seminal vesicles, possesses piriform to oval-shaped testes with spermatozoa grouped in apical bundles and dense filamentous material filling other areas. The vasa deferentia are long and a pair of elongated accessory glands displays distinct proximal and distal regions. The relatively short (∼40 µm) spermatozoa are nucleated, aflagellated, and immobile. Further research could explore variations and assess the taxonomic utility of these features for genus identification within Hydropsychidae.

Sox21b underlies the rapid diversification of a novel male genital structure between Drosophila species.

The emergence and diversification of morphological novelties is a major feature of animal evolution.1,2,3,4,5,6,7,8,9 However, relatively little is known about the genetic basis of the evolution of novel structures and the mechanisms underlying their diversification. The epandrial posterior lobes of male genitalia are a novelty of particular Drosophila species.10,11,12,13 The lobes grasp the female ovipositor and insert between her abdominal tergites and, therefore, are important for copulation and species recognition.10,11,12,14,15,16,17 The posterior lobes likely evolved from co-option of a Hox-regulated gene network from the posterior spiracles10 and have since diversified in morphology in the D. simulans clade, in particular, over the last 240,000 years, driven by sexual selection.18,19,20,21 The genetic basis of this diversification is polygenic but, to the best of our knowledge, none of the causative genes have been identified.22,23,24,25,26,27,28,29,30 Identifying the genes underlying the diversification of these secondary sexual structures is essential to understanding the evolutionary impact on copulation and species recognition. Here, we show that Sox21b negatively regulates posterior lobe size. This is consistent with expanded Sox21b expression in D. mauritiana, which develops smaller posterior lobes than D. simulans. We tested this by generating reciprocal hemizygotes and confirmed that changes in Sox21b underlie posterior lobe evolution between these species. Furthermore, we found that posterior lobe size differences caused by the species-specific allele of Sox21b significantly affect copulation duration. Taken together, our study reveals the genetic basis for the sexual-selection-driven diversification of a novel morphological structure and its functional impact on copulatory behavior.

Morphology of the male reproductive system and spermatozoa of Mahanarva fimbriolata (Stål, 1854) (Hemiptera: Cercopidae) with evidence of a spermatostyle in the sperm conjugation.

Changes in harvesting methods in the early 1990s led to Mahanarva fimbriolata becoming the most prevalent pest in sugarcane plantations. Encouraged by the scarcity of research on the reproductive system and spermatology of Auchenorrhyncha, we provide a detailed description of the male reproductive system and spermatozoa of this cercopid. This will not only aid in taxonomic purposes but also help in understanding the reproductive biology of the species. The male reproductive system, spermatozoa, and sperm bundles of M. fimbriolata were investigated using light microscopy. Our results reveal a reproductive system consisting of a pair of testes, each with 36 follicles, two vasa deferentia, two well-developed seminal vesicles, a single pair of accessory glands, and an ejaculatory duct. Here, we also describe and explore the particularities of the formation of secondary sperm bundles, where cells interestingly bind only to the apical region of the spermatostyle. We also propose some possible benefits of this unusual organization for the reproductive success of the species.

Rapid divergent evolution of internal female genitalia and the coevolution of male genital morphology revealed by micro-computed tomography.

Animal genitalia are thought to evolve rapidly and divergently in response to sexual selection. Studies of genital evolution have focused largely on male genitalia. The paucity of work on female genital morphology is probably due to problems faced in quantifying shape variation, due to their composition and accessibility. Here we use a combination of micro-computed tomography, landmark free shape quantification and phylogenetic analysis to quantify the rate of female genital shape evolution among 29 species of Antichiropus millipedes, and their coevolution with male genitalia. We found significant variation in female and male genital shape among species. Male genital shape showed a stronger phylogenetic signal than female genital shape, although the phylogenetic signal effect sizes did not differ significantly. Male genital shape was found to be evolving 1.2 times faster than female genital shape. Female and male genital shape exhibited strong correlated evolution, indicating that genital shape changes in one sex are associated with corresponding changes in the genital shape of the other sex. This study adds novel insight into our growing understanding of how female genitalia can evolve rapidly and divergently, and highlights the advantages of three-dimensional techniques and multivariate analyses in studies of female genital evolution.

The evolution of female-biased genital diversity in bedbugs (Cimicidae).

Rapid genitalia evolution is believed to be mainly driven by sexual selection. Recently, noncopulatory genital functions have been suggested to exert stronger selection pressure on female genitalia than copulatory functions. In bedbugs (Cimicidae), the impact of the copulatory function can be isolated from the noncopulatory impact. Unlike in other taxa, female copulatory organs have no function in egg-laying or waste-product expulsion. Males perform traumatic mating by piercing the female integument, thereby imposing antagonistic selection on females and suspending selection to morphologically match female genitalia. We found the location of the copulatory organ evolved rapidly, changing twice between dorsal and ventral sides, and several times along the anteroposterior and the left-right axes. Male genital length and shape varied much less, did not appear to follow the positional changes seen in females, and showed no evidence for coevolution. Female genitalia position evolved 1.5 times faster than male genital length and shape and showed little neutral or geographic signals. Instead, we propose that nonmorphological male traits, such as mating behavior, may drive female genitalia morphology in this taxon. Models of genitalia evolution may benefit from considering morphological genital responses to nonmorphological stimuli, such as male mating behavior or copulatory position.

Morphology of the Female and Male Reproductive Tracts and More Data on the Spermatostyle in the Brazilian Gyretes sp. (Coleoptera, Adephaga, Gyrinidae).

We investigated the male and female reproductive tracts of Gyretes sp. with light and transmission electron microscopies. The male has a pair of testes with a single coiled follicle, followed by short efferent ducts, which have a similar shape and diameter to the testes. Long ducts (epididymides) with differential epithelium open in a pair of long vasa deferentia that lead to the accessory glands. Glycoprotein secretions from the vas deferens epithelium constitute the spermatostyle for spermatozoa aggregation. The female has numerous ovarioles per ovary, a coiled fertilization duct, an accessory gland, and an elongated vagina. Spermatozoa are stored as unaggregated cells in the fertilization duct. In Gyrinidae, the testes and accessory glands show diverse shapes, and the female sperm storage organs vary in shape, size, and type and may play a role in the interaction with sperm aggregates. Testes with a single follicle and vasa deferentia opening in the accessory glands of Gyretes sp. are features shared with other Gyrinidae and other Adephaga. We proposed adding this latter trait to characterize this suborder of beetles. The morphology of the reproductive organs in both sexes contributes to comparative analyses and knowledge of the reproductive biology of Gyretes and may provide additional features for systematics.

Divergence in the internal genital morphology of females and correlated divergence in male intromittent structures among populations of a millipede.

Our understanding of genital evolution comes largely from studies of male genitalia. Females have received far less attention because of the difficulties inherent in quantifying the shapes of their internal genital structures. Here we combine advances in micro-computed tomography with a new landmark free method of quantifying three-dimensional trait shape, to document patterns of divergence in female genital shape, and the correlated divergence of male genitalia among populations of the millipede Antichiropus variabilis. We used single-nucleotide polymorphisms to estimate levels of neutral genetic divergence among seven populations of millipede. Genetic divergence was high and correlated with geographic distance. Comparing phenotypic divergence in genital shape to neutral genetic divergence, we found that genital shape for both females and males has diverged more than would be expected from random drift, consistent with a pattern of directional selection. While there was significant covariation between female and male genital shape across populations, the magnitude of divergence in genital shape between the sexes was not correlated. Our results demonstrate the utility of using three-dimensional scanning technologies to examine female genital traits and add to a small but growing number of studies showing that like male genitalia, female genitalia can be under strong directional selection.

Functional morphology of the praying mantis male genitalia (Insecta: Mantodea).

Male genitalia in praying mantids are highly complex, but we know little of how they function. I combined the micro-computed tomography of a copulating pair of the European mantis (Mantis religiosa) with public videos of copulation in various species of Mantodea and an analysis of literature. The function of each major element is reviewed. Copulation is divided into three phases: opening, anchoring and deposition. The opening is achieved by pulling the female subgenital plate with the male apical process. Multiple cases of female cooperation or resistance were observed and one case of coercion by the male. In species with the reduced apical process, female cooperation is mandatory. The male subgenital plate may participate in the opening as an integral part of the genitalia. After the opening, the conformation of the genitalia drastically changes, revealing activity of the genital papilla. Tight grasp on female genitalia is maintained solely by the clamp on the right phallomere, despite the overall complexity and predictions of sexual conflict theory. Other prominent elements show rhythmic motions, but their functions are not entirely clear and evidently involve spermatophore deposition, female stimulation or rival sperm removal. The opening and anchoring are similar in Mantodea and Blattodea, but achieved with non-homologous elements.

Male reproductive system of the freshwater prawn Macrobrachium brasiliense (Decapoda: Palaemonidae): Notes on spermatophore formation and sperm count.

Studies on the morphology of the reproductive system are essential for understanding the reproduction processes of species or even within genera or families. The present study aimed to describe the functional morphology of the male reproductive system, spermatophore formation, and sperm count of Macrobrachium brasiliense. The anatomy of the reproductive system consists of a pair of testes from which the vasa deferentia (VD) starts, extending to the fifth pair of pereopods. The VD is divided into three regions: proximal (PVD), middle (MVD), and distal (DVD). In the PVD, there is a prominent fold, the typhlosole, formed by columnar cells. The typhlosole disappears in the MVD, being incorporated into one of the faces of the VD wall, identified by its simple columnar epithelium while the remainder of the vessel wall is formed by squamous or simple cubic epithelium. Columnar cells produce type-II and III secretion. The epithelium in the DVD is made up only of cubic cells. Low sperm concentration was observed when compared to other species of the genus Macrobrachium. In conclusion, the typhlosole and columnar epithelium are responsible for the asymmetric spermatophore, which seems the pattern of Macrobrachium that is probably shared with other caridean shrimps.

Resolving between novelty and homology in the rapidly evolving phallus of Drosophila.

The genitalia present some of the most rapidly evolving anatomical structures in the animal kingdom, possessing a variety of parts that can distinguish recently diverged species. In the Drosophila melanogaster group, the phallus is adorned with several processes, pointed outgrowths, that are similar in size and shape between species. However, the complex three-dimensional nature of the phallus can obscure the exact connection points of each process. Previous descriptions based upon adult morphology have primarily assigned phallic processes by their approximate positions in the phallus and have remained largely agnostic regarding their homology relationships. In the absence of clearly identified homology, it can be challenging to model when each structure first evolved. Here, we employ a comparative developmental analysis of these processes in eight members of the melanogaster species group to precisely identify the tissue from which each process forms. Our results indicate that adult phallic processes arise from three pupal primordia in all species. We found that in some cases the same primordia generate homologous structures whereas in other cases, different primordia produce phenotypically similar but remarkably non-homologous structures. This suggests that the same gene regulatory network may have been redeployed to different primordia to induce phenotypically similar traits. Our results highlight how traits diversify and can be redeployed, even at short evolutionary scales.

Male genital organs of the black-crowned dwarf marmoset (Callibella humilis).

This study provides the first morphological description of the male genital organs of black-crowned dwarf marmoset (Callibella humilis). Internal and external genital organs were similar to other species of non-human primates. However, some shape and size differences were noted. The penile shaft was laterally flattened and comprised of two corpus cavernosus. These were split by a septum up to the level of the glans and then merged to form a single structure. The glans penis had small, keratinized spicules arising from epidermal or dermal projections. The small, fully ossified and well-mineralized penile bone, located at the distal end of the penis, consisted of a bone matrix surrounded by sparse osteoblasts and well-developed internal osteocytes. The penile urethra was lined with columnar pseudostratified epithelium, with areas of simple cuboidal epithelium. The testes were small relative to the body compared to other primate species. The findings of this work may support comparative studies of primate reproductive ecology.

Investigation of male genital system anatomy in the New Zealand rabbit (Oryctolagus cuniculus L.).

Rabbits are frequently used in research because of their human-like biological structure. In the present study, 10 male rabbits were preferred. Arterial vascularization of the genital system organs were dissected. Morphometric and macroanatomical results of these organs were taken, and some organs were examined by magnetic resonance imaging (MRI). In this study, right testis length was measured at 67.24 ± 5.36 mm and left testis length was 62.25 ± 6.55 mm in New Zealand rabbits. Testicular weight was 10.21 ± 1.17 g on the right and 9.90 ± 1.15 g on the left. Right caput epididymidis 0.68 ± 0.08 g, left caput epididymidis 0.80 ± 0.13 g; right corpus epididymidis 0.14 ± 0.03 left corpus epididymidis 0.15 ± 0.03 g; right cauda epididymidis 1.87 ± 0.26 g left cauda epididymidis 1.90 ± 0.31 g. In the present study, right ductus deferens weight was 0.30 ± 0.29 g, and left ductus deferens weight was 0.25 ± 0.03 g; the ampulla ductus deferentis weight was 0.35 ± 0.16 g on the right side and 0.37 ± 0.16 g on the left side. The length of the vesicular gland glandula vesicularis was calculated as 18.54 ± 0.35 mm on the right and 17.55 ± 0.59 mm on the left. The width of the vesicular gland was measured as 16.54 ± 0.28 mm on the right and 16.70 ± 0.45 mm on the left. Vesicular gland weight was 0.91 ± 0.07 g on the right side and 0.96 ± 0.09 g on the left side. The prostate length was recorded as 11.68 ± 2.01 mm and width as 13.02 ± 1.38 mm. The length of the bulbourethral gland was 13.36 ± 2.00 mm on the right side and 12.39 ± 1.21 mm on the left. Its width was recorded as 6.73 ± 0.98 mm on the right and 5.80 ± 0.90 mm on the left. Respectively, it weighed 0.40 ± 0.20 g on the right and 0.44 ± 0.24 g on the left. The prostate consisted of three parts in rabbits: the proprostate, the corpus prostate and the paraprostate. The bulbourethral gland was a green lentil-sized gland found in pairs. It is thought that the obtained results will contribute to the scientific researches on male genital system in laboratory animals and other animal species, artificial insemination studies, reproductive system diseases and operations in rabbits.

Two new species of Oxyethira Eaton 1873 (Trichoptera: Hydroptilidae) from Roraima state, Brazil.

Two new species of Oxyethira from Brazil are described: Oxyethira (Dampfitrichia) jiquitaia sp. nov., and Oxyethira (Tanytrichia) librina sp. nov. Illustrations of male genitalia are provided with each description. These results increase the number of Oxyethira species in Brazil from 37 to 39.

Morphology of the male reproductive tract of Eira barbara.

Eira barbara, popularly known as irara, is a medium-sized carnivore member of the Mustelidae family. Despite its important role in the ecosystems in which its lives, data on the internal morphology of E. barbara remains scarce. Therefore, this study aimed to provide knowledge regarding the anatomy of the male reproductive system of this species to improve understanding of its reproduction to inform its conservation. We studied seven specimens who had died after being run over. The specimens were dissected for the evaluation of the reproductive system, which comprised a globular scrotum; a small pendulum covered with light-coloured hair; a pair of testicles of firm consistency and ellipsoid shape and suspended in the scrotum by the spermatic cord; a paired duct system; an ampoule of the deferens duct and prostate constituting the set of attached glands; a urethra divided into pelvic and penile portions; a penis with a baculum having a novel "C" shaped apex; and a prepuce. Microscopically, the testicular parenchyma consisted of seminiferous tubules separated by intertubular spaces formed by loose connective tissue, fibrocytes, Leydig cells, and blood and lymph vessels. The epididymis was surrounded by a capsule of dense connective tissue and extended to form septa. The baculum was microscopically classified as a compact bone containing several bony lamellae with osteocytes and osteoblasts. The macro and microscopic findings were generally similar to those of domestic carnivores, with some notable differences.

Anatomo-histological evaluation of male reproductive system of the juvenile Caiman crocodilus yacare / Evaluación anátomo-histológica del sistema reproductor del Caiman crocodilus yacare macho juvenil

SUMMARY: The Caiman crocodilus yacare was once close to extinction. Studies about the male reproductive tract may aid in their reproduction and conservation. In this work, after sedation and euthanasia, seven young male C. yacare were submitted to necropsy, and macroscopic evaluation of the reproductive system, while the three others were admitted for histological study. The histological sections were stained with Hematoxylin & Eosin and Masson's Trichrome. After opening the pleuroperitoneal cavity it was possible to identify that the testicles were disposed in pairs and attached to its dorsal surface. The epididymis showed elongated and convoluted shapes and were located at the cranial margin of the testicles, following its medial portion, which was the same portion that the "vas deferens" stems from until the opening of the cloaca. The crocodile phallus presented a tubular shape, with conical appearance, displaying little resistance while maintaining its flexibility, compatible with a fibrocartilaginous tissue. On light microscopic analysis it was possible to observe that the testis was delimited by the tunica albuginea. The seminiferous tubules were contorted, and the interstitial space was filled with interstitial tissue and Leydig cells. The epididymal ductus were covered with non-ciliated pseudostratified epithelium with cells varying between cuboidal and prismatic shapes. The ductus deferens were characterized by a narrow girth shrouded with non- ciliated pseudostratified prismatic epithelium. The phallus of the crocodile was covered with a non-keratinized squamous epithelium surrounded by connective tissue. The findings support anatomic and histologic knowledge Alligatoridae reproductive system, enabling further research in the C. yacare reproduction and conservation.

RESUMEN: El Caiman crocodilus yacare ha estado en peligro de extinción. Los estudios sobre el aparato reproductor del macho pueden ser de ayuda en su reproducción y conservación. En este trabajo, fueron sometidos a necropsia y evaluación macroscópica del aparato reproductor, siete machos jóvenes de C. yacare, mientras que otros tres fueron utilizados para su estudio histológico. Las secciones histológicas se tiñeron con hematoxilina y eosina y tricrómico de Masson. Después de examinar la cavidad pleuroperitoneal se pudo identificar que los testículos estaban dispuestos en pares y adheridos a su superficie dorsal. El epidídimo presentaba formas alargadas y contorneadas y se ubicaba en el margen craneal de los testículos, siguiendo su porción medial, que era la misma porción de donde parten los conductos deferentes hasta la apertura de la cloaca. El pene del cocodrilo presentaba forma tubular, de apariencia cónica, mostrando poca resistencia manteniendo su flexibilidad, compatible con un tejido fibrocartilaginoso. En el análisis microscópico óptico se pudo observar que el testículo estaba delimitado por la túnica albugínea. Los túbulos seminíferos estaban contorsionados y el espacio intersticial estaba lleno de tejido intersticial y células intersticiales (células de Leydig). El epidídimo estaba cubierto con epitelio pseudoestratificado no ciliado con células que variaban entre formas cuboideas y prismáticas. Los conductos deferentes se caracterizaron por una circunferencia estrecha envuelta en un epitelio prismático pseudoestratificado no ciliado. El pene del cocodrilo estaba cubierto con un epitelio escamoso no queratinizado rodeado de tejido conectivo. Los hallazgos corroboran el conocimiento de la anatomía del sistema reproductivo de Alligatoridae, lo que permite una mayor investigación sobre la reproducción y conservación de C. yacare.

Pediculus humanus capitis: a study of the male genitalia using a combined stereoscopic, confocal laser scanning, and scanning electron microscopy approach.

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.

Phylogenetic analysis of the family Megalopodidae (Coleoptera: Chrysomeloidea): better taxon-sampling facilitates detection of new relationships and new taxa.

The systematics of Megalopodidae is not adequately known, in spite of it being a relatively small group of phytophagous beetles. The first phylogenetic analysis of Megalopodidae with a comprehensive generic representation (25 genera of 30 described, 10 subgenera and 77 species) is undertaken. A parsimony analysis under equal and implied weights was carried out based on 147 adult and larval morphological characters. Subfamilies Palophaginae and Zeugophorinae were recovered as monophyletic, by contrast with Megalopodinae, which proved to be paraphyletic. Atelederinae are proposed as a new subfamily. Also, three tribes and three subtribes within Megalopodinae are proposed: Leucasteini trib.n., Sphondyliini trib.n. and Megalopodini, the latter including Macrolophina subtrib.n., Temnaspidina subtrib.n. and Megalopodina. The genera Macrolopha, Kuilua, Poecilomorpha, Temnaspis, Antonaria, Agathomerus, Megalopus and Bothromegalopus were recovered as non-monophyletic. New delimitations of the polyphyletic genera Poecilomorpha and Macrolopha are proposed, Clythraxeloma is resurrected, and the subgenera of Agathomerus are suppressed. The following new combinations are proposed: Kuilua apicata (Fairmaire), K. nyassae (Jacoby), Poecilomorpha cribricollis (Pic), P. minuta (Pic), Clythraxeloma assamensis (Jacoby), C. bipartita (Lacordaeri), C. discolineata (Pic), C. downesii (Baly), C. gerstaeckeri (Westwood), C. laosensis (Pic), C. maculata (Pic), C. mouhoti (Baly), C. nigrocyanea (Motschulsky), C. pretiosa (Reineck), Temnaspis tricoloripes (Pic) and Barticaria faciatus (Dalman). Clythraxeloma cyanipennis Kraatz is a restored combination. Distribution patterns of Megalopodidae largely conform to the breakup of Gondwanaland, with its main clades having particular distributions: Andean-Australian (Palophaginae), Ethiopian (Leucasteini, Sphondyliini, and Macrolophina), Neotropical (Ateledrinae and Megalopodina) and Ethiopian-Oriental-Palaearctic (Temnaspidina the result of a secondary expansion. Zeugophorinae present a worldwide distribution, except for the Neotropical and Andean regions, which may be the result of geodispersal. The findings of the present study also shed light on groups with taxonomic issues, where phylogenetic analyses are strongly needed.

Evolution of sexual dimorphism and polychromatism in a lineage of tiger moths (Lepidoptera: Erebidae): advancing knowledge of a taxonomically chaotic group.

Pericopina is divided into 36 genera, with the greatest diversity recorded in the Neotropics. Studies on the taxonomy and systematics of pericopines are scarce, and one of the few phylogenetic hypotheses available in the literature places some Afro-Indo-Malayan lineages among the Neotropical representatives. Through a survey of adult morphological characters, we analyzed the phylogenetic relationships in Pericopina including Nyctemera and other Afro-Indo-Malayan genera as putative members of this subtribe. Additionally, we tested the monophyly of Dysschema, a key genus to understanding the evolutionary patterns of the extreme sexual dimorphism and polychromatism in Pericopina. Our cladistic analysis, based on 162 morphological characters, suggests that Pericopina is a polyphyletic group. Xenosoma is the only genus among the Neotropical pericopines related to the Afro-Indo-Malayan species; Scearctia is closely related to Lithosiini, and Pteroodes shows morphological similarities with Phaegopterina. Additionally, Seileria is a new junior subjective synonym of Thyrgis. The monophyly of Dysschema is supported only if the monotypic genera Myserla and Are are included. These are herein designated new synonyms of Dysschema. Our findings suggest that intersexual polychromatism and intersexual polymorphism for wing characters have arisen multiple times in the evolutionary history of Pericopina. Intersexual polychromatism is also widely distributed within Dysschema, perhaps representing a derived feature with multiple origins in the genus.

Size, shape, and direction matters: Matching secondary genital structures in male and female mites using multiple microscopy techniques and 3D modeling.

Studies of female genital structures have generally lagged behind comparable studies of male genitalia, in part because of an assumption of a lower level of variability, but also because internal genitalia are much more difficult to study. Using multiple microscopy techniques, including video stereomicroscopy, fluorescence microscopy, low-temperature scanning electron microscopy (LT-SEM), and confocal laser scanning microscopy (CLSM) we examined whether the complex sperm transfer structures in males of Megalolaelaps colossus (Acari: Mesostigmata) are matched by similarly complex internal structures in the female. While both LT-SEM and CLSM are well suited for obtaining high-quality surface images, CLSM also proved to be a valuable technique for observing internal anatomical structures. The long and coiled sperm transfer organ on the chelicera of the males (spermatodactyl) largely matches an equally complex, but internal, spiral structure in the females in shape, size, and direction. This result strongly suggests some form of genital coevolution. A hypothesis of sexual conflict appears to provide the best fit for all available data (morphology and life history).

A morphological, histological and histochemical study of the sexual segment of the kidney of the male Chamaeleo calyptratus (veiled chameleon) / Un estudio morfológico, histológico e histoquímico del segmento sexual del riñón del macho Chamaeleo calyptratus (camaleón velado)

SUMMARY: This study aimed to describe the morphology, histology, and histochemistry of the kidneys and the sexual segment of the kidney (SSK) in Chamaeleo calyptratus (Yemen chameleons or veiled chameleons) collected during the active reproductive season. To achieve this objective, a total of 7 mature male Chamaeleo calyptratus were captured from their natural habitats from different areas in the Aseer region of Saudi Arabia and transferred to the reptilian laboratory where their kidneys were dissected out. Next, a morphological examination was conducted on the kidneys and the SSK was processed for light microscopic examinations with the primary focus placed on the morphology and histology of the SSK. The results of the study showed that Chamaeleo calyptratus possess two, reddish-brown, attenuated kidneys divided into lobes and lobules (lobulated). The histological study showed that the chameleons had no distinct limits between the cortex and medulla of the kidneys. In general, similar with other reptiles, this lizard demonstrated that the kidneys have few nephrons, do not show any nephron loop (loop of Henle), and display few glomeruli. The nephron is generally composed of standard components: renal corpuscle, glomerulus surrounded by a double-walled, the glomerular capsule (Bowman's capsule) and renal tubules (six renal tubular segments differentiated as the ciliated neck segment [between the glomerulus and the proximal segment], proximal segment, ciliated intermediate segment instead of nephron loop that connects proximal and distal, distal segment, terminal segment or sexual segment, and all segments emptying into the collecting ducts. The epithelial tissues lining the lumen of these segments vary from simple cuboidal cells to columnar and tall columnar cells in the SSK. Mature male Chamaeleo calyptratus possess hypertrophied parts of the distal renal segments, which are called the SSK. Histologically, the active SSK consists of simple tall columnar epithelial cells with rounded basal nuclei with clear centralized nucleoli and numerous apical coarse secretory granules which are released from the cells by an apocrine process. Histochemically, the secretory granules stain positively for proteins with mercuric bromophenol blue and react intensely to periodic acid-Schiff (PAS) for neutral carbohydrates. This is the first report about the histology of the SSK of the Chamaeleo calyptratus, and this study adds to the knowledge of the reproductive biology, biodiversity, and reproductive strategies of chameleons. Further studies are required to investigate the ultrastructure of the kidneys and SSK.

RESUMEN: Este estudio tuvo como objetivo describir la morfología, histología e histoquímica de los riñones y el segmento sexual en el riñón (SSK) del Chamaeleo calyptratus (camaleones de Yemen o camaleones con velo) recolectados durante la temporada reproductiva. Un total de 7 machos maduros de Chamaeleo calyptratus fueron capturados en su hábitat natural de diferentes áreas en la región de Aseer de Arabia Saudita y transferidos al laboratorio de reptiles donde fueron disecados los riñones. Posteriormente, se llevó a cabo un examen morfológico de los riñones y se procesó la SSK para exámenes con microscopio óptico con el enfoque principal puesto en la morfología y la histología. Los resultados del estudio mostraron que Chamaeleo calyptratus posee dos riñones atenuados de color marrón rojizo divididos en lóbulos (lobulados). En el estudio histológico se observó que los riñones de los camaleones no tenían límites definidos entre la corteza y la médula. En general, y similar a otros reptiles, este lagarto demostró que los riñones tienen pocas nefronas, no muestran ningún asa de Henle y presentan pocos glomérulos. La nefrona está compuesta por componentes estándar: corpúsculo renal (glomérulo rodeado por una pared de doble pared). Cápsula de Bowman y túbulos renales (seis segmentos tubulares renales diferenciados como el segmento del cuello ciliado [entre el glomérulo y el segmento proximal], segmento proximal, segmento intermedio ciliado en lugar del asa de Henle que conecta proximal y distal, segmento distal, segmento terminal o segmento sexual y todos los segmentos que desembocan en los conductos colectores Los tejidos epiteliales que recubren la luz de estos segmentos varían desde células cuboidales simples hasta células columnares y columnares altas en la SSK. Los machos maduros de Chamaeleo calyptratus poseen partes hipertrofiadas de los segmentos renales distales, denominados SSK. Histológicamente, la SSK activa consiste en células epiteliales cilíndricas altas simples con núcleos basales redondeados, nucléolos centralizados claros y gránulos secretores gruesos apicales que se liberan de las células por un proceso apocrino. Histoquímicamente, los gránulos secretores se tiñen positivamente para las proteínas con azul de bromofenol mercúrico y reaccionan intensamente al ácido periódico-Schiff (PAS) para obtener carbohidratos neutros. Este es el primer informe sobre la histología de la SSK de Chamaeleo calyptratus, y se suma al conocimiento de la biología reproductiva, la biodiversidad y las estrategias reproductivas de los camaleones. Se requieren más estudios para investigar la ultraestructura de los riñones y la SSK.