Copulatory Piece Research Articles

The development of extremely large male genitalia under spatial limitation.

Extensive research in evolutionary biology has focused on the exaggeration of sexual traits; however, the developmental basis of exaggerated sexual traits has only been determined in a few cases. The evolution of exaggerated sexual traits may involve the relaxation of constraints or developmental processes mitigating constraints. Ground beetles in the subgenus Ohomopterus (genus Carabus) have species-specific genitalia that show coevolutionary divergence between the sexes. Here, we examined the morphogenesis of the remarkably enlarged male and female genitalia of Carabus uenoi by X-ray microcomputed tomography. The morphogenetic processes generating the male and female genitalia at the pupal stage were qualitatively similar to those in closely related species with standard genital sizes. Higher growth rates contributed to the exaggeration of both the male and female genital parts of C. uenoi, possibly related to a gene network commonly upregulated in both sexes. Additionally, the length of the copulatory piece (CP), the enlarged male genital part stored in the aedeagus (AD), reached close to that of the AD at the later developmental stages and thereafter decelerated to grow in parallel with the AD, suggesting a structural constraint on the CP by the outer AD. Then, unlike related species, the lengths of the CP and AD increased at eclosion, suggesting a mechanism leading to further elongation of the male genitalia. These observations suggest that a developmental process allows continuous growth of the male genitalia even under the spatial limitation. These results revealed the spatio-temporal dynamics of the development of exaggerated genital structures under structural constraints.

A new subgenus of Epaphiopsis Uéno, 1953 (Coleoptera: Carabidae: Trechini) discovered in the mountains of South-East Asia, and a new species of the subgenus Allepaphiama with atypical characteristics

Summary The Epaphiopsis complex, a complex of trechine ground beetle genera, is composed of the genus Epaphiopsis and six other genera, all of which are endemic to the Far East. Since an exhaustive definition of this genus complex has not been available to date, the general morphology of all the constituent genera of the Epaphiopsis complex is presented here. A new subgenus of Epaphiopsis, Shunichiepaphius n. subgen., is created for a new species, E. unidentata n. sp., discovered from northern Vietnam. This monotypic new subgenus, and its type species, are characterized by the strongly transverse microsculpture covering the nearly entire dorsal surface of head; by the first discal setiferous pore of elytra located in interstria 4; by the preapical pore of elytra located before the level of the anterior end of recurrent stria; by the large copulatory piece of endophallus which is doubled and knot-shaped with the apical part rounded; and above all by the male protarsi with only the first segment dilated and denticulate inwards. A new species of the subgenus Allepaphiama, E. (A.) beni n. sp., was collected in the Solukhumbu district of Nepal, which is the border between the range of the Trechus rolwalingensis species-group and the previously known range of the subgenus Allepaphiama. This new species bears a reduced chaetotaxy, i.e. only one seta on each side of the clypeus, and, as in the species described by Schmidt in 2016, only two discal setae in stria 3 (or interval 4) but without discal seta in stria 5. Finally, to help a better understanding of the systematics of the Epaphiopsis complex, a preliminary overview of the female ectodermic genital tract of the taxa belonging to the Epaphiopsis complex and several other taxa of Trechini is presented.

Heterochrony and growth rate variation mediate the development of divergent genital morphologies in closely related Ohomopterus ground beetles.

The rapid divergence of genital morphology is well studied in the context of sexual selection and speciation; however, little is known about the developmental mechanisms underlying divergence in genitalia. Ground beetles in the subgenus Ohomopterus genus Carabus have species-specific genitalia that show coevolutionary divergence between the sexes. In this study, using X-ray microcomputed tomography, we examined the morphogenesis of male and female genitalia in two closely related Ohomopterus species with divergent genital morphologies. The morphogenetic processes generating the male and female genitalia at the pupal stage were qualitatively similar in the two species. The male aedeagus and internal sac and female bursa copulatrix were partially formed at pupation and developed gradually thereafter. The species-specific genital parts, male copulatory piece, and female vaginal appendix differed in the timing and rate of development. The relatively long copulatory piece of Carabus maiyasanus began to develop earlier, but subsequent rates of growth were similar in the two species. The timing of the formation of the vaginal appendix and initial growth rates were similar, but subsequent rapid growth led to a longer vaginal appendix in C. maiyasanus. Thus, substantial interspecific differences in the size of genital parts were mediated by different underlying developmental mechanisms between the sexes (i.e., a shift in the developmental schedule in males and a change in growth rate in females). These results revealed the spatio-temporal dynamics of species-specific genital structure development, providing a novel platform for evo-devo studies of the diversification of genital morphologies.

Knockdown of rotund gene through larval RNA interference affects genital and elytral morphology in the ground beetle Carabus maiyasanus (Coleoptera: Carabidae)

AbstractInterspecific variation in genital morphology contributes to prezygotic reproductive isolation in many insect species. However, developmental genes affecting genital morphology are poorly understood. We undertook larval RNA interference (RNAi) experiments with rotund (rn) gene in the ground beetle Carabus (Ohomopterus) maiyasanus to examine the knockdown effects of this gene on genital development. We injected double‐stranded RNA (dsRNA) into third instar larvae of C. maiyasanus. The injection of rn dsRNA resulted in the absence or deformation of the copulatory piece in the male genitalia, which is a characteristic part playing a role in species‐specific genital coupling between the sexes. In addition, the rn dsRNA injection resulted in shortened elytra in both sexes, which is related to the known role of rn in forewing formation in Drosophila. Our study suggests that rn plays a previously underappreciated role in male genital development and potentially contributes to genital diversity in this beetle group.

Dactylogyrid monogeneans parasitising Cyphocharax voga (Hensel) (Teleostei: Curimatidae) from the Pampas region, Argentina: new and previously described species.

Most studies on dactylogyrid monogeneans in Argentina have been carried out during 1980s and 1990s. Many of these species have been later synonymised and other remain under a confusing taxonomic status, particularly those parasitising Cyphocharax voga (Hensel) (Teleostei: Curimatidae). In order to clarify the identity of dactylogyrids, new material was collected from fishes in Lake Chascomús, Buenos Aires Province, Argentina. A total of four species was found in the gills of C. voga. Two known species, Curvianchoratus singularis (Suriano, 1980) Suriano, 1986 and Palombitrema triangulum (Suriano, 1981) Suriano, 1997, are redescribed and their generic and specific status discussed, and two new species are described. Urocleidoides surianoae n. sp. can be distinguished from its congeners by having an anterior medial projection in the ventral bar and a laminar ligament connecting the base of the male copulatory organ and accessory piece. Annulotrematoides bonaerensis n. sp. differs from its congeners principally by having a ventral bar with an anterior medial projection. The diversity of dactylogyrids harboured by C. voga indicates the need of further studies in the Pampas region, which will provide interesting and valuable sources of evidence for future zoogeographical and evolutionary research on dactylogyrids in the Neotropics.

How the length of genital parts affects copulation performance in a carabid beetle: implications for correlated genital evolution between the sexes

To identify factors leading to the correlated evolution of exaggerated male and female genitalia, we studied the effects of the variable dimensions of corresponding functional genital parts (male copulatory piece and female vaginal appendix) on copulatory performance in the polygamous carabid beetle Carabus (Ohomopterus) maiyasanus. We used mating pairs of individuals from two populations to increase the variances in genital dimensions and determined the copulation performance (insemination and spermatophore replacement, and copulation time) in single- and double-mating situations. In single mating, insemination success was not affected by genital dimensions, although the copulation time was significantly shorter when the male aedeagus was longer. In the double-mating experiment, insemination and replacement of spermatophores by the second male succeeded more frequently when the copulatory piece was shorter and the vaginal appendix was longer, and when the difference between the length of the copulatory piece and the vaginal appendix was smaller. Thus, a matching of the corresponding genital parts between the sexes increases the male's reproductive success in sperm competition, but elongation of the copulatory piece cannot be explained simply by the improvement in male reproductive success. We discuss possible factors for the elongation of genital parts in terms of sexual conflict and reproductive interference through interspecific copulation.

A NEW SPECIES OF TRECHUS FROM THE ETHIOPIAN PLATEAU (Coleoptera, Carabidae)

A new species of <em>Trechus</em> from the Oromia Province (Ethiopia) is described in the present note. This new taxon shows some peculiar characters, such as a much swollen abdomen of pseudophysiogastric aspect, a feature shared by other high altitude Trechinae, as for instance <em>Queinnectrechus</em> Deuve, 1992 from Asia. The integuments are glabrous; the antennae are short; the pronotum is larger than long, with regularly rounded sides and hind angles; the elytrae are short and rounded (pseudophysiogastric) with the first six striae well engraved, on the third of them two discal foveolate setae are well visible. The aedeagus is big and stout, abruptly narrowing at the tip (in lateral view), with a small botton slanting upwards; the copulatory piece is big and well sclerified, triangular, with a more or less sharpened tip. Well recognizable for the “pseudophysiogastric” aspect, <em>Trechus (Trechus) ericalis</em> n.sp. belongs to the <em>bipartitus</em> group.

A NEW SUBGENUS AND TWO NEW SPECIES OF TRECHUS FROM ETHIOPIA (Coleoptera, Carabidae)

Two new species of <em>Trechus</em> from the Oromia Province (Ethiopia) are described in the present note. In the first part we describe <em>Archeotrechus</em>, a new microphtalmic <em>Trechus</em>, characterized by the dilation of only the first tarsal segment in males and by the aedeagus with the dorsal part amost completely divided into two lobes: a sclerified connection exists only in the region of the basal ostium. To this subgenus we ascribe the new species <em>Trechus</em> (<em>Archeotrechus</em>) <em>relictus</em>, from the area of Mt. Sgona (Batu), of yellow-brown colour, rather flattened, with non sinuate pronotum and blunt fore and hind angles; two discal setae in the third stria. The aedeagus is much elongated, with a spherical apical button, copulatory piece triangular, lanceolate, with a sharp apex, little sclerified and very simple, typical of ancestral forms, like for instance <em>Minitrechus</em> Vigna Taglianti & Magrini, 2009. The female gonostyli, short and curved, bear at the apex two big setae on the inner edge. In the second part of the note we describe <em>Trechus</em> (s. str.) <em>oromiensis</em>, a new species of <em>bipartitus</em> Group (sensu novo), characterized by the presence of only one discal seta on elytra and by peculiar features of the aedeagus.

Stenomastigus pseudofranzi sp. n., from South Africa (Staphylinidae, Scydmaeninae)

A new species of the endemic South African genus Stenomastigus Leleup (Staphylinidae, Scydmaeninae, Mastigini), S.pseudofranzi sp. n. is described. Because some morphological structures of the new species highly resemble those of S.franzi Leleup, description of the latter species is supplemented with previously unknown details of the aedeagus (includingthe copulatory piece). Habitus, aedeagi, modified fore legs of males and other diagnostic characters of both species are illustrated.

A new genus and a species of trechine ground beetles (Coleoptera: Carabidae: Trechinae) from the Republic of Srpska (Bosnia and Herzegovina)

A new genus (Punctoduvalius gen. n.) and a species of trechine ground beetles (Punctoduvalius orlovacensis sp. n.) from Bosnia and Herzegovina have been described and diagnosed. Punctoduvalius gen. n. is clearly distinct from all other phenetically close genera in many important respects, such as: the presence of depigmented reduced eyes, the presence of a pigmented eye border, the presence of deep and complete frontal furrows, the presence of tiny setae on the genae, the presence of distinct longitudinal fissures on the protibias, the ratio of length/width of the first protarsal article in males, the presence of two elytral discal setae, the presence of numerous setiferous punctures in interstrial spaces, the specific position of the humeral setae, and the specific shape of the copulatory piece. This new genus comprises four species: Punctoduvalius pilifer (Ganglbauer, 1891) (endogean from Mts. Treskavica and Bjelasnica, and from a cave on Mt. Visocica, Bosnia and Herzegovina), P. protectus (Winkler, 1926) (from the Pecina kod Ostojica Cave, Mt. Treskavica, and endogean from Mt. Jahorina, Bosnia and Herzegovina), P. brevipilosus (Knirsch, 1927) (endogean from Lupoglav Peak, Mt. Prenj, Bosnia and Herzegovina), and P. orlovacensis sp. n. (from the Orlovaca Cave, village of Donje Bisevo, near Pale, Bosnia and Herzegovina). The four species clearly differ in many important respects. The following three taxonomic changes are proposed: Punctoduvalius pilifer (Ganglbauer, 1891), comb. n., P. protectus (Winkler, 1926), comb. n., and P. brevipilosus (Knirsch, 1927), comb. n. The new genus and its members belong to an old separate phyletic lineage, distinct from all other existing species groups. Additionally, these forms are relict and endemic to the deep soil and caves of Bosnia and Herzegovina.

Dactylogyrus robisoni n. sp. (Monogenoidea: Dactylogyridae) from the Bluehead Shiner, Pteronotropis hubbsi (Bailey and Robison), 1978 (Pisces: Cyprinidae)

Abstract Dactylogyrus robisoni n. sp. is described from the bluehead shiner, Pteronotropis hubbsi (Bailey and Robison), 1978, in Arkansas, U.S.A. Dactylogyrus robisoni is morphologically most similar to Dactylogyrus moorei Monaco and Mizelle, 1955, and Dactylogyrus ornatus Rogers, 1967, by possessing a long, slender, often sinuous copulatory accessory piece. The accessory piece of D. robisoni differs from those of the other 2 species by lacking a medial ramus and terminating in an elongate bulb.

QTL for the species‐specific male and female genital morphologies in Ohomopterus ground beetles

Animals with internal fertilization often exhibit marked diversification in genital morphology among closely related species. However, our knowledge of the genetic architecture underlying genital evolution is still limited. We constructed genetic linkage maps and analysed quantitative trait loci (QTL) for F(2) hybrids of two closely related species of the carabid beetles Carabus (Ohomopterus) iwawakianus and C.(O.) maiyasanus, which show matching male and female genital shapes within species, but marked differences in genital morphologies between species. The linkage maps comprised both amplified fragment length polymorphism and microsatellite markers. Composite interval mapping to detect QTL for three traits of male copulatory piece (length, width, weight) and two traits for female vaginal appendix (length, width) resulted in the detection of one to five significant QTL for each trait. The QTL explained large proportions of phenotypic variance. Thus, the interspecific difference in the genital morphologies appeared to be determined by relatively small numbers of genes with large genetic effects. QTL of different traits for the same or different sexes co-occurred on five of eight linkage groups with significant QTL; in particular, three QTL for different male and female genital traits occurred almost at the same position. Each of the male genital traits showed uniform signs of additive genetic effects, suggesting that directional selection has led to species-specific morphologies. However, the signs of additive genetic effects in each female genital trait were not uniform, suggesting that coevolution between sexes is not necessarily concerted. This result requires further assessment because the sample size of F(2) females was small.

Microncocotyle bicoccae n. gen., n. sp. (Monogenoidea: Dactylogyridae) from the Gills of the Longtail Silverbiddy, Gerres longirostris (Teleostei: Gerreidae), in the Red Sea, Egypt

Abstract Microncocotyle bicoccae n. sp. (Monogenoidea; Dactylogyridae) is described from the gill filaments of the longtail silverbiddy, Gerres longirostris (Teleostei: Gerreidae), collected from Ras Mohammed National Park near Sharm El-Sheikh, Egypt. The monotypic Microncocotyle gen. n. is proposed for this species and is characterized, in part, by its members possessing a cup-shaped haptor armed with a ventral anchor/bar complex (dorsal complex absent); 14 hooks with pairs 2–4, 6 and 7 marginal and pairs 1 and 5 central in the haptor; one pair of eyespots; confluent intestinal ceca lacking diverticula; tandem gonads; a vas deferens looping the left intestinal cecum; articulated male copulatory organ and accessory piece; and a dextromarginal vaginal pore. Maximum parsimony and Bayesian interference analyses of the 18S rDNA gene suggest that Microncocotyle originated independently of two other dactylogyrid genera, Dactylogyrus and Pseudodactylogyrus, in which species possess a single anchor/bar complex.

A NEW SUBGENUS AND A NEW SPECIES OF TRECHUS FROM ETHIOPIA (COLEOPTERA, CARABIDAE)

In the present note Minitrechus, a new subgenus of <em>Trechus</em>, characterized in the 75 male by only the first tarsal segment dilated and dentate, and by much enlarged paramera, bearing three apical setae, clearly isolated from each other, is described. The new species, <em>Trechus</em> (<em>Minitrechus</em>) <em>gypaeti</em>, is light yellow in colour, rather flattened, with little eyes, pronotum not sinuate, with fore and hind angles blunt; third elytral stria with two discal setae. The median lobe of the aedeagus is short, stout, little arcuate, with a copulatory piece triangular, lanceolate and sharpened at the tip, little sclerified. Female gonostyli short and curved, bear a stout and long ensiform seta on the inner edge, flanked by two smaller ones.

Genital lock-and-key system and premating isolation by mate preference in carabid beetles (Carabus subgenus Ohomopterus)

The shapes and lengths of copulatory pieces and vaginal appendices of the carabid beetle subgenus Ohomopterus (genus Carabus) vary among species. In Japan, the species in the group with a medium body size (C. yaconinus, C. iwawakianus, C. maiyasanus, C. uenoi, C. arrowianus, C. esakii, and C. insulicola) are usually allopatric or parapatric, except at Mt Kongosan, where C. uenoi, C. iwawakianus, and C. yaconinus are sympatrically distributed. The degree of premating isolation by mate preference was high between sympatric populations, irrespective of the genetic distance between them. However, premating isolation was absent between parapatric populations. The degree of premating isolation for allopatric populations spanned a wide range of isolation values. Thus, mate discrimination by males seems to have evolved mostly between sympatric pairs. These results suggest two hypotheses. First, premating isolation has evolved through reinforcement or through reproductive character displacement after sympatric contact. Second, premating isolation has evolved in allopatry, and as a result of premating isolation, the species can coexist in sympatry. We also examined the degree of mechanical isolation between C. uenoi and C. iwawakianus (a sympatric pair), which have a very large difference in the length of the copulatory piece. The insertion success was low and only one female produced viable offspring among 15 crosses; however, death in females due to copulation was rare. For sympatric matings between C. uenoi and C. iwawakianus, a large difference in the genital size might reduce the gene flow with small mating costs. Gene flow that was significantly reduced by genital difference might cause either the evolution of premating isolation through reinforcement/reproductive character displacement or through the maintenance of a high degree of premating isolation following sympatric contact. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87, 145–154.

Kosaniniella javorensis n. gen., n. sp., from southwest Serbia, with notes on the evolutionary status of Knirschiella Guéorguiev, Cholevidae, Coleoptera

A new genus and species of endogen cholevid beetles (Kosaniniella javorensis n. gen., n. sp) has been diagnosed and described from under stones in the valley of Suvodol, village of Debelja, near Nova Varos, Mt. Javor southwestern Serbia. This new genus clearly differs from all other closely related genera in the following correlative traits: Body size presence/absence of eye spots; length of distalmost antennomere; form of antennomere VIII; punctuation of elytra; presence/absence of sutural striae shape of elytra; form of aedeagus; shape of aedeagal sides; shape of parameral apex; form of paramerae; distribution of parameral setae; shape of anterior inner parameral seta; form of median part of copulatory piece length of basal bulbus; and form of spermatheca. Kosaniniella n. gen. belongs to a separate phyletic lineage which includes two other phenetically close genera, Magdelainella Jeannel and Knirschiella Gu?orguiev. The new genus is present in southwestern Serbia only, while Magdelainella inhabits Serbia and Bosnia and Herzegovina. Knirschiella is given full generic status in the present paper; its members are known from Albania. The Kosaniniella-Magdelainella-Knirschiella complex is probably of early Tertiary age, its species having originated during the Alpine Orogeny, which affected vast areas of the Balkan Peninsula, including the Dinarids otherwise their terra typica.

Javorella, a new genus of endemic ground beetles (Trechini, Carabidae, Coleoptera) from west and southwest Serbia

A new genus and species of cave ground beetles (Javorella javorensis n. gen. n. sp) has been described from the Pecina pod Kapilijama Cave, village Trudovo, nr. Nova Varos, southwestern Serbia. This new genus is clearly distinct from all other genera in many important respects such as: the presence of unfunctional flattened reduced eyes, the presence of 10-14 depigmented ommatidia, the presence of a pigmented oval eye border, the presence of deep and complete frontal furrows (but shallow and less visible in their posterior thirds), the presence of completely smooth cheeks, the presence of distinct furrows on fore tibias along their length, the ratio of the length/breadth of the first article of protarsomere in male; the presence of 2 elytral discal setae, the specific position of humeral setae and the unique shape of the copulatory piece. This new genus comprises also an additional species, J. suvoborensis (Pavicevic and Popovic), described elsewhere from the Pecina u Brezacima Cave, village Brezaci, Rajac, Mt. Suvobor, near Valjevo, western Serbia. The two species clearly differ in many important respects; the new genus and its members belong to an old and separate phyletic lineage, distinct from all other existing species groups. Additionally, these forms are relic and endemic to Serbian caves.

Mating behavior, insemination and sperm transfer in the ground beetle Carabus insulicola.

Mating behavior and the processes of insemination and sperm transfer in the ground beetle Carabus insulicola were analyzed. C. insulicola has elaborate genitalia, in which the strongly sclerotized male copulatory piece is inserted into the female vaginal appendix in copula. During mating, I observed pre-copulatory struggles of males and females, as well as delays in ejaculation, suggesting the presence of intersexual conflicts. Insemination was achieved with a spermatophore, which strongly adhered to the openings of the spermatheca, common oviduct, and vaginal appendix. The spermatophore dissolved after copulation, and sperm were transferred into the spermatheca within three hours after copulation. Sperm bundles were contained within the testes and spermatophores, but free spermatozoa were found in the spermatheca.

Consequences of hybridization between Ohomopterus insulicola and O. arrowianus (Coleoptera, Carabidae) in a segmented river basin: parallel formation of hybrid swarms

A putative hybrid zone between flightless carabid beetles, Carabus (Ohomopterus)insulicola and C. (O.) arrowianus nakamurai in the Ina Valley, central Honshu, Japan, was studied using experimental hybridization and morphological analysis. The principal morphological character analysed was a functional part of the male genitalia (the copulatory piece), which is also the key diagnostic character in taxonomy. The habitat of the carabid beetles is fragmented by the Tenryu River, which runs through the Ina Valley, and its tributaries. Ohomopterus insulicola and O. a. nakamurai occur in the upstream and downstream areas of the river basin, respectively, and a putative hybrid swarm (O. insulicola ssp. pseudinsulicola) is found in the boundary area on the east side of the Tenryu River. Experimental hybridization between O. insulicola and O. a. nakamurai resulted in F1offspring that were morphologically similar to O. i. pseudinsulicola. Pre-zygotic reproductive isolation was incomplete, although the F1males had a dysfunction in sperm production and were almost sterile. Only a single F1pair produced F2. Backcrosses of F1females of males of the parental species resulted in offspring that were similar to the parental species in genital morphology. Based on the discriminant function for the shape of the copulatory piece resulting from the experimental hybridization, we demonstrate that similar hybrid swarms exist on both sides of the Tenryu River, but in locations 25 km apart. This demonstrates parallelism in hybridization events with similar consequences. The hybrid swarms consisted of beetles with intermediate morphological characters and did not contain obvious parental forms. The establishment of such intermediate populations may have been facilitated by selection for fertile hybrids in segregated local sites in the absence of frequent immigration of parental species. This study suggests that a segmented river basin provides an opportunity for establishing novel evolutionary lineages resulting from hybridization.

Atheta (Badura) ehnstroemi n.sp. (Coleoptera: Staphylinidae), with short review of other known species of Badura

AbstractAtheta (Badura) ehnstroemi n.sp. is described from material collected in central and northern Sweden. The lectotype of A. macrocera (Thomson) is designated. A key to the known species of Badura is given. Their diagnostic characters and taxonomic relationship to each other is discussed. Species of Badura can easily be distinguished by the shape of median lobe and copulatory piece of aedeagus but a number of other important characters are also mentioned. Ecological and distributional information is given for each species.