Male Morphology Research Articles

Eight new species of Dexosarcophaga Townsend, 1917 (Diptera, Sarcophagidae) from the Neotropical Region

Eight new Neotropical species of Dexosarcophaga Townsend, 1917 are described, five from Brazil, Dexosarcophaga phoenix sp. nov., Dexosarcophaga jandainae sp. nov., Dexosarcophaga patiuorum sp. nov., Dexosarcophaga petra sp. nov., and Dexosarcophaga sphaera sp. nov., one from Costa Rica, Dexosarcophaga limon sp. nov., one from Ecuador, Dexosarcophaga napo sp. nov., and one from Colombia, Dexosarcophaga pallida sp. nov. Male and female morphology is documented with photographs and illustrations, including details of the male terminalia for all new species and female terminalia of Dexosarcophaga phoenix sp. nov. and Dexosarcophaga sphaera sp. nov. With the addition of these new species, 58 species of Dexosarcophaga are now known, with records from the American continent spanning from the southern United States to northern Argentina.

From the Ethiopian Bale Mountains hotspotFilopalpinae subfam. nov., a new taxon of Laniatorean harvestmen based on external and genital morphology (Arachnida, Opiliones, Assamiidae).

Filopalpinae subfam. nov. is proposed as a new subfamily within family Assamiidae based on a new genus, Filopalpus gen. nov. and on five new species: F. joschmidti sp. nov., F. bale sp. nov., F. kakaensis sp. nov., F. altomontanus sp. nov. and F. niger sp. nov. All originate from the highlands of Ethiopia, namely the Bale Mountains and adjacent volcanoes in Oromia State. Species of the new subfamily are characterized by dense body cover with pointed tubercles causing a hedgehog appearance of the body (dorsal side, partly ventral side), extreme sexual dimorphism in pedipalps (in males thread-like long and thin surpassing body length by about four to six times, devoid of apophyses and thorns; in females short and stout about body length, with a distal grasping hand formed by apophyses and strong setae of tibia and tarsus, and tarsal claw). Male genital morphology is characterized by a hemolymph-pressure system of truncus penis and glans, a dorsal sub-distal tube-like glans with an inner prickly funnel, which is everted by hemolymph pressure during courtship. These male genital characters place the present species in Assamiidae, but external morphology points to a strongly different separate evolutionary unit within this family. The five species known to date were secured at altitudes between 2830 and 4100 m. At least two of the collecting areas are now devoid of forest due to human impact. To secure the present specimens at high-altitude localities was possible only by searching in remote microhabitats unavailable for cattle and man-made fire. A perspective on current subfamilies of Assamiidae and on pedipalpal morphology and evolution is presented.

Himalaea batanga, a new species from Southwest China (Lepidoptera: Noctuidae: Amphipyrinae: Psaphidini)

A new species of the genus Himalaea Hreblay & L. Ronkay, 1998, Himalaea batanga sp. n. is described from western Sichuan Province of China. The new species is the second known member of the genus well different from the type species in both external and male genitalia morphology. Adults and male genitalia of both species of Himalaea are illustrated.

Taxonomic revision of the Apiomerus maya species group (Heteroptera: Reduviidae: Harpactorinae).

The Apiomerus maya species group of the genus Apiomerus Hahn, 1831 (Hemiptera: Heteroptera: Reduviidae: Harpactorinae: Apiomerini), the bee assassins, is revised. Four species that are native to parts of Mexico and Central America are recognized and redescribed: Apiomerus maya Dispons, 1971, A. pipil Dispons, 1971, A. venosus Stl, 1872, and A. immundus Bergroth, 1898. Intraspecific polychromatism and male genital morphology are documented for the group. The taxonomy of two previously recognized species is updated: A. tristis Champion, 1899 syn. nov. is here synonymized with A. venosus and A. guatemalensis Dispons, 1971 syn. nov. with A. pipil.

Electrocommunication signals and aggressive behavior vary among male morphs in an apteronotid fish, Compsaraia samueli.

Within-species variation in male morphology is common among vertebrates and is often characterized by dramatic differences in behavior and hormonal profiles. Males with divergent morphs also often use communication signals in a status-dependent way. Weakly electric knifefish are an excellent system for studying variation in male morphology and communication and its hormonal control. Knifefish transiently modulate the frequency of their electric organ discharge (EOD) during social encounters to produce chirps and rises. In the knifefish Compsaraia samueli, males vary extensively in jaw length. EODs and their modulations (chirps and rises) have never been investigated in this species, so it is unclear whether jaw length is related to the function of these signals. We used three behavioral assays to analyze EOD modulations in male C. samueli: (1) artificial playbacks, (2) relatively brief, live agonistic dyadic encounters, and (3) long-term overnight recordings. We also measured circulating levels of two androgens, 11-ketotestosterone and testosterone. Chirp structure varied within and across individuals in response to artificial playback, but was unrelated to jaw length. Males with longer jaws were more often dominant in dyadic interactions. Chirps and rises were correlated with and preceded attacks regardless of status, suggesting these signals function in aggression. In longer-term interactions, chirp rate declined after 1week of pairing, but was unrelated to male morphology. Levels of circulating androgens were low and not predictive of jaw length or EOD signal parameters. These results suggest that communication signals and variation in male morphology are linked to outcomes of non-breeding agonistic contests.

Is Internal Rotation Measurement of the Hip Useful for Ruling in Cam or Pincer Morphology in Asymptomatic Males? A Diagnostic Accuracy Study.

Cam and pincer morphologies are associated with limited internal rotation. However, the routine clinical examination for hip rotation has limited reliability. A more standardized method of measuring hip rotation might increase test-retest and interobserver reliability and might be useful as a screening test to detect different hip morphologies without the need for imaging. We developed an examination chair to standardize the measurement of internal hip rotation, which improved interobserver reliability. However, the diagnostic test accuracy for this test is unknown. Is a standardized method of determining internal hip rotation using an examination chair useful in detecting cam and pincer morphology with MRI as a reference standard? A diagnostic test accuracy study was conducted in a sample of asymptomatic males. Using an examination chair with a standardized seated position, internal rotation was measured in 1080 men aged 18 to 21 years who had been conscripted for the Swiss army. The chair prevents compensatory movement by stabilizing the pelvis and the thighs with belts. The force to produce the internal rotation was standardized with a pulley system. Previous results showed that the measurements with the examination chair are similar to clinical assessment but with higher interobserver agreement. A random sample of 430 asymptomatic males was invited to undergo hip MRI. Of those, 244 White European males responded to the invitation and had a mean age of 20 ± 0.7 years and a mean internal rotation of the hip of 33° ± 8.5°. Using MRI as the reference standard, 69% (169 of 244) had a normal hip, 24% (59 of 244) a definite cam morphology (Grades 2 and 3), 3% (8 of 244) an increased acetabular depth, and 3% (8 of 244) a combination of both. One experienced radiologist graded cam morphology as follows: 0 = normal, 1 = mild, 2 = moderate, and 3 = severe. Pincer morphology was defined by increased acetabular depth (≤ 3 mm distance between the center of the femoral neck and the line connecting the anterior and posterior acetabular rims). The intraobserver agreement was substantial (weighted κ of 0.65). A receiver operating characteristic (ROC) curve was fitted, and sensitivity, specificity, and likelihood ratios were estimated for different internal rotation cutoffs. For cam morphology, the area under the ROC curve was 0.75 (95% CI 0.67 to 0.82). Internal hip rotation of less than 20° yielded a positive likelihood ratio of 9.57 (sensitivity 0.13, specificity 0.99), and a value of 40° or more resulted in a negative likelihood ratio of 0.36 (sensitivity 0.93, specificity 0.20). The area under the curve for detecting the combination of cam and pincer morphologies was 0.87 (95% CI 0.74 to 1.0). A cutoff of 20° yielded a positive likelihood ratio of 9.03 (sensitivity 0.33, specificity 0.96). This examination chair showed moderate-to-good diagnostic value to rule in hip cam morphology in White European males. However, at the extremes of the 95% confidence intervals, diagnostic performance would be poor. Nonetheless, we believe this test can contribute to identifying cam morphologies, and we hope that future, larger studies-ideally in more diverse patient populations-will seek to validate this to arrive at more precise estimates of the diagnostic performance of this test. Level III, diagnostic study.

Three new species of the spider genus Liphistius (Araneae, Mesothelae, Liphistiidae) from Thailand.

We diagnose and describe three new species of the primitively segmented spider genus Liphistius from Thailand, based on male palp and female genital morphology: L.hatyai Zhan & Xu, sp. nov. (♂♀), L.keeratikiati Zhan & Xu, sp. nov. (♂♀), and L.inthanon Zhan & Xu, sp. nov. (♂♀). The classification of the three new species of Liphistius is discussed: L.hatyai sp. nov. and L.keeratikiati sp. nov. are assigned to the trang-group, and L.inthanon sp. nov. is placed in the bristowei-group according to male palp and female genital morphology.

Testing Morphological Relationships Between Female and Male Copulatory Structures in Bats.

The lower reproductive tract of female mammals has several competing functions including mating, tract health maintenance, and parturition. Diverse vaginal anatomy suggests interactions between natural and sexual selection, yet despite its importance, female copulatory morphology remains under-studied. We undertook a comparative study across the species-rich mammalian order Chiroptera (bats) with a focus on the suborder Yangochiroptera (Vespertilioniformes) to examine how female vaginal features may have coevolved with male penis morphology to minimize mechanical damage to their tissues during copulation. The penis morphology is diverse, presenting great potential for post-copulatory sexual selection and coevolution with the female morphology, but vaginas have not been carefully examined. Here we test the hypotheses that vaginal thickness and collagen density have coevolved with features of the male penis including the presence of spines and a baculum. We present histological data from females of 24 species from 7 families of bats, and corresponding data on male penis anatomy. We also examine the role of phylogenetic history in the morphological patterns we observe. We found evidence that female vaginal thickness has coevolved with the presence of penile spines, but not with baculum presence or width. Collagen density did not appear to covary with male penile features. Our findings highlight the importance of considering interactions between the sexes in influencing functional reproductive structures and examine how these structures have been under selection in bats.

Clinical Significance of Epstein-Barr Virus and Helicobacter pylori Infection in Gastric Carcinoma.

Epstein-Barr virus (EBV) and Helicobacter pylori (HP) coinfection may synergistically induce severe inflammatory responses in the stomach tissue, increasing the risk of developing gastric cancer. We aimed to analyze the effect of EBV and HP coinfection on the clinicopathologic features and prognosis of gastric cancer, as well as to evaluate the role of EBV infection in non-gastric carcinoma with lymphoid stroma (non-GCLS). Overall, 956 patients who underwent surgery for gastric cancer between September 2014 and August 2015 were eligible and divided into groups, according to GCLS morphology, EBV infection, and HP infection. Clinicopathologic characteristics and oncologic outcomes were analyzed retrospectively. EBV and HP coinfection was significantly associated with male sex, proximal location, GCLS morphology, and equivocal p53 expression (p<0.001). Multivariate analysis revealed that EBV infection alone (hazard ratio [HR], 0.362; 95% CI, 0.131 to 0.996; p=0.049) and lower third location (HR, 0.624; 95% CI, 0.413 to 0.943; p=0.025) were inversely correlated with overall survival. During median follow-up period of 72 months, overall survival rate was not significantly different between the EBV and HP coinfection group and others (97.6% vs 86.8%; log-rank p=0.144). In non-GCLS patients (n=920), overall survival rate was not significantly different between the EBV infection group and others (96.9% vs 86.4%; log-rank p=0.126). EBV and HP coinfection is not an independent prognostic factor for gastric cancer. EBV infection status, regardless of HP infection, affects the clinicopathologic features of all types of gastric cancer. However, it does not lead to a significant difference in overall survival of non-GCLS patients.

Revision of the new Australasian orb-weaving spider genus Salsa (Araneae, Araneidae).

A new Australasian genus in the orb-weaving spider family Araneidae Clerck, 1757 is described to include seven species: Salsafuliginata (L. Koch, 1871) comb. nov. (type species; = Epeirarubicundula Keyserling, 1887) syn. nov.) (Australia, introduced to New Zealand); S.brisbanae (L. Koch, 1867) comb. nov. (Australia); S.canalae (Berland, 1924) comb. nov. (New Caledonia); S.neneba sp. nov. (Papua New Guinea); S.recherchensis (Main, 1954) comb. nov. (Australia); S.rueda sp. nov. (Australia); and S.tartara sp. nov. (Australia; Lord Howe Island endemic). Salsa gen. nov. belongs to the Australasian informal backobourkiine clade and differs from other genera of this clade by a distinct abdominal shape (single posterior abdominal tubercle) and ventral colouration (pale lateral spindle-shaped bands), male pedipalp morphology (C-shaped median apophysis that has teeth-like tubercles inside the basal arch) and the shape of the female epigyne scape (partially translucent and generally shorter than the epigyne plate). Based mainly on male pedipalp morphology within the backobourkiines, Salsa gen. nov. has closest morphological affinities with Acroaspis Karsch, 1878 and Socca Framenau, Castanheira & Vink, 2022.

Revision of Taiwanese and Ryukyuan species of Pristepyris Kieffer, 1905, with description of a new species (Hymenoptera, Bethylidae).

The pristocerine genus Pristepyris comprises 38 valid species recorded worldwide, except in the Australian Region. Of them, three species, namely P.mieae (Terayama, 1995), P.tainanensis (Terayama, 1995) and P.takasago (Terayama, 1996), have been recorded from Taiwan and three species, i.e. P.ishigakiensis (Yasumatsu, 1955), P.minutus (Yasumatsu, 1955) and P.ryukyuensis (Terayama, 1999), from the Ryukyus in Japan. In the present study, the species-level classification of both Taiwanese and Ryukyuan species of Pristepyris was revised using newly-collected specimens by the external and male genital morphological as well as molecular phylogenetic analysis. Overall, six species of Pristepyris were recorded from Taiwan and the Ryukyus. Among these, five were previously recorded for the region and were revised here: P.ishigakiensis, P.mieae, P.ryukyuensis, P.tainanensis and P.zhejiangensis. Additionally, a new species, P.seqalu sp. nov., is herein described and illustrated. Furthermore, the species P.minutus is transferred to Eleganesia and P.takasago is synonymized under P.minutus. Due to the new combination of Pristepyrisminutus, a key to Taiwanese and Ryukyuan species of the genus Eleganesia, based on male morphology, is provided in Appendix 1. We confirmed for the first time the correspondence between the male and female species of P.zhejiangensis by molecular data. High compatibility in species delimitation patterns, suggested by the morphological and molecular phylogenetic approaches, highlighted the significance of the former approach for accurately classifying aged voucher specimens of Pristocerinae in public collections.

Description of a new species of Laelaspis Berlese (Acari: Mesostigmata: Laelapidae) from Brazil, with a key to the species of the Western Hemisphere.

Laelaspis loeckii Duarte Moreira sp. nov. is described based on the morphology of adult females and males collected from soil in a survey carried out in southern Brazil, in the temperate Pampa biome. This is the first species of this genus described from this country. A key to the species that have so far been reported from the Western Hemisphere is provided.

Effects of genetic vs. environmental quality on condition-dependent morphological and life history traits in a neriid fly.

Condition is assumed to reflect both genes and environment, enabling condition‐dependent signals to reveal genetic quality. However, because the phenotypic effects of variation in genetic quality could be masked by environmental heterogeneity, the contribution of genetic quality to phenotypic variation in fitness‐related traits and condition‐dependent signals remains unclear. We compared effects of ecologically relevant manipulations of environmental quality (nutrient dilution in the larval diet) and genetic quality (one generation of inbreeding) on male and female morphology, life history and reproductive performance in the neriid fly Telostylinus angusticollis. We found that larval diet quality had strong, positive effects on male and female body size, male secondary sexual traits, and aspects of male and female reproductive performance. By contrast, inbreeding had weak effects on most traits, and no trait showed clear and consistent effects of both environmental and genetic quality. Indeed, inbreeding effects on body size and male competitive performance were of opposite sign in rich vs. poor larval diet treatment groups. Our results suggest that environmental quality strongly affects condition, but the effects of genetic quality are subtle and environment‐dependent in this species. These findings raise questions about the genetic architecture of condition and the potential for condition‐dependent traits to function as signals of genetic quality.

Evolution of genes involved in the unusual genitals of the bear macaque, Macaca arctoides.

Genital divergence is thought to contribute to reproductive barriers by establishing a “lock‐and‐key" mechanism for reproductive compatibility. One such example, Macaca arctoides, the bear macaque, has compensatory changes in both male and female genital morphology as compared to close relatives. M. arctoides also has a complex evolutionary history, having extensive introgression between the fascicularis and sinica macaque species groups. Here, phylogenetic relationships were analyzed via whole‐genome sequences from five species, including M. arctoides, and two species each from the putative parental species groups. This analysis revealed ~3x more genomic regions supported placement in the sinica species group as compared to the fascicularis species group. Additionally, introgression analysis of the M. arctoides genome revealed it is a mosaic of recent polymorphisms shared with both species groups. To examine the evolution of their unique genital morphology further, the prevalence of candidate genes involved in genital morphology was compared against genome‐wide outliers in various population genetic metrics of diversity, divergence, introgression, and selection, while accounting for background variation in recombination rate. This analysis identified 67 outlier genes, including several genes that influence baculum morphology in mice, which were of interest since the bear macaque has the longest primate baculum. The mean of four of the seven population genetic metrics was statistically different in the candidate genes as compared to the rest of the genome, suggesting that genes involved in genital morphology have increased divergence and decreased diversity beyond expectations. These results highlight specific genes that may have played a role in shaping the unique genital morphology in the bear macaque.

Sattleria enrosadira sp. nov., a new cryptic, high alpine species from Northern Italy revealed by DNA barcodes and morphology (Lepidoptera, Gelechiidae).

Sattleria karsholti Huemer Hebert, 2011 is re-examined based on recently collected material, museum vouchers, and DNA barcodes. Adult and male genitalia morphology and molecular data of the COI barcode region support the existence of two allopatric species, S. karsholti, from the type locality of Pizo Arera in the Orobian Alps (Bergamo Province, Italy), and S. enrosadira sp. nov. from Monte Baldo, Adamello and the Brenta group (Trento and Verona Provinces, Italy). Adults and male genitalia of both species are figured; the females of both species are unknown.

Ecology and behavior of the troglobitic harvestman Jimeneziella decui Avram, 1970 (Arachnida: Opiliones)

The troglobitic harvestman Jimeneziella decui Avram, 1970 is known from four neighboring caves (Cueva de Majana, Cueva de los Golondrinos, Cueva Perla del Agua, and Cueva de Máximo) located in eastern Cuba. We present the first ecological data on a population of this endangered species in Cueva de Máximo. The sex ratio of the population estimated in the main gallery of the cave was not different from 1:1. The spatial distribution observed was uniform, and the density of individuals was 0.48 individuals/m2 (February–March) and 0.84 individuals/m2 (November). We describe morphological differences between the sexes and between males. Preliminary morphological and behavioral data suggests the possible existence of two male morphs in J. decui (“robust” and “slender” males). The slender males possessed less developed armature on leg IV; and the chelicerae, coxa IV and femur IV were less swollen than robust males. Our observations on male-male interactions suggest that robust males are more aggressive than slender males, which never initiated an attack on robust males, but in some occasions responded to attacks from robust males. The non-aggressive behavior exhibited by robust males towards slender males also suggests that the slender morph is not only a sneaker, but potentially a female mimic, which is also consistent with the morphology of slender males. Ecological and behavioral information also suggests the possible existence of territories defended by robust males with their well-developed weapons, and the presence of females inside them.

The role of epigynal setae in mate choice in the orb-weaver Leucauge argyra

Male and female genital morphology may have strong effects on fitness in spiders. Females of some species of Leucauge produce mating plugs that partially or totally block the entrances to their insemination ducts on the epigynum, forming barriers that reduce the probabilities of future inseminations. While in some species both females and males participate in plug formation, the mating plugs in L. argyra are produced exclusively by females. The epigynum of L. argyra (Walckenaer 1841) is unusual in having a prominent ventral process covered on its anterior side and around its base with long, thick setae. We tested whether male stimulation of these epigynal setae affected female plug formation by removing them from some females but not others. Females lacking setae produced mating plugs immediately after copulation less often than unmanipulated females. However, 24 hr later the mating plugs had disappeared in many females of the treatment group. Setae removal did not affect the amount of sperm stored in the female spermatheca, or the frequency of female attacks. The rate of male genital inflations correlated positively, but mating duration was negatively correlated with sperm stored in female’s spermathecae. Females attempted to attack small males more often than large males. These findings contribute to our understanding of the function of the setae associated with the female genitalia, and the effect of their tactile stimulation on plug formation, and transference of spermatozoids.

Immature Stages of Nilio (Micronilio) Pusillus Ihering, 1914 (Coleoptera: Tenebrionidae) with Redescription of Adults and New Distributional Records

The immature stages (larvae and pupae) of Nilio (Micronilio) pusillus Ihering, 1914 are described and illustrated for the first time. A redescription of adults is provided, including the male and female terminalia morphology. Nilio (M.) pusillus is recorded from Paraná State, Brazil, for the first time, while some biological aspects of the species are described. In addition, a lectotype of N. (M.) pusillus Ihering, 1914 is designated.

Multi-modal locomotor costs favor smaller males in a sexually dimorphic leaf-mimicking insect

BackgroundIn most arthropods, adult females are larger than males, and male competition is a race to quickly locate and mate with scattered females (scramble competition polygyny). Variation in body size among males may confer advantages that depend on context. Smaller males may be favored due to more efficient locomotion leading to higher mobility during mate searching. Alternatively, larger males may benefit from increased speed and higher survivorship. While the relationship between male body size and mobility has been investigated in several systems, how different aspects of male body morphology specifically affect their locomotor performance in different contexts is often unclear.ResultsUsing a combination of empirical measures of flight performance and modelling of body aerodynamics, we show that large body size impairs flight performance in male leaf insects (Phyllium philippinicum), a species where relatively small and skinny males fly through the canopy in search of large sedentary females. Smaller males were more agile in the air and ascended more rapidly during flight. Our models further predicted that variation in body shape would affect body lift and drag but suggested that flight costs may not explain the evolution of strong sexual dimorphism in body shape in this species. Finally, empirical measurements of substrate adhesion and subsequent modelling of landing impact forces suggested that smaller males had a lower risk of detaching from the substrates on which they walk and land.ConclusionsBy showing that male body size impairs their flight and substrate adhesion performance, we provide support to the hypothesis that smaller scrambling males benefit from an increased locomotor performance and shed light on the evolution of sexual dimorphism in scramble competition mating systems.

Onyx disparamphis sp. n. (Nematoda, Desmodorida) from South Korea with a taxonomic review of the genus.

A new free-living marine nematode Onyx disparamphis sp. n. (Nematoda, Desmodorida) is described from sandy littoral of Jeju Island, South Korea. The new species differs from all other Onyx species by the unusual amphideal fovea morphology in males (elongated loop). O. disparamphis relates to O. balochinensis, and O. brevispiculatum by having simple non-double terminal pharyngeal bulb and relatively small and straight, non-sigmoid supplementary organs, but differs from them by smaller body length, shorter cephalic setae, smaller terminal pharyngeal bulb, smaller spicules, number of supplementary organs and tail shape expressed as ratio tail length/anal diameter. The genus Onyx is revised with updated genus diagnosis, and an annotated list of 23 valid species is presented. Onyx ferox is considered species inquirenda because the species is known only from a sole immature female specimen, while within Onyx, the males provide the most important distinguishing characters such as enlarged and complicated amphids, supplementary organs and copulatory spicules. For species identification, a pictorial key consisting of illustrations of simplified icons of male heads and posterior body sections, as well as a table of the most important morphometric and numerical characters are provided. Geographical distribution and habitat specifity of Onyx species is analysed briefly.