Distal Genitalia Research Articles

First record of Hygromia cinctella (Draparnaud, 1801) (Gastropoda: Hygromiidae) in Ukraine outside Crimea

The second record of Hygromia cinctella in Ukraine is described, which is also the first record of this species in its western part. The snails were found in March 2023 in Uzhhorod, Transcarpathian region. Live specimens, their shells, and distal genitalia are shown. Possible sources for the H. cinctella population at the studied site are discussed.

Three introduced Monacha species (Gastropoda: Hygromiidae) in and near Lviv with remarks on M. cartusiana spreading in Ukraine and its Western part

The distribution of three introduced Monacha species in Lviv and its immediate environs was analysed. For this, adult snails collected at 33 sites from 2011 to 2022 were studied anatomically. We found Monacha fruticola in two sites (Lviv, Briukhovychi), two cryptic species M. cartusiana and M. claustralis in 4 sites (Lviv, Yampil), only M. claustralis in one site in Lviv, and only M. cartusiana (single individuals or populations) in the remaining 26 cases. The distal genitalia of M. claustralis from new discoveries in and near Lviv, the variability of the vagina shape in M. cartusiana and M. claustralis from the studied area are shown. The possible role of private cars in the rapid spread of M. cartusiana in the study area is discussed. The chronology of registration of M. cartusiana in Western Ukraine is shown in a tabular format. A significant expansion of the range of M. cartusiana in Ukraine was noted, although almost until the very end of the 20th century this species was mentioned only for the southern part of the country, including Crimea.

Case Report : Cervical Cellular Angiofibroma

Background: Cellular angiofibroma is a rare benign tumor in the distal genitalia introduced by Nucci et al in 1997 that can occur in both women and men with an age range of 46 – 54 years. In women it usually occurs in the vulva and vagina. These tumors are often diagnosed as Bartholin cysts, vulvar cysts, myomas, and unspecified complex tumors.
 Objective: Report a case of cellular angiofibroma previously diagnosed with cervical myoma
 Case: A 51-year-old female patient para 5 abortion 0 with complaints of lumps that have been felt to come in and out since 4 months but since 1 week it feels enlarged and cannot be inserted again, and diagnosed as cervical tumor. History of menopause since 1 year ago. The general condition of the patient is good with vital signs within normal limits. On physical examination of the abdomen, there was no tumor mass, tenderness or flux. On inspection, there was a reddish mass coming out of the vaginal introitus with some blackish necrotic appearance. On vaginal examination, a mass with a solid consistency was found with the impression of the cervix with a border of the tumor stalk that was not palpable. In this patient, Total Abdominal Hysterectomy and Bilateral Salpingoophorectomy were performed and the tissue was examined for anatomical pathology with cervical angiofibroma results with non-specific chronic inflammation and atypical complex endometrial gland hyperplasia. 
 Conclusion : Cellular angiofibroma is a rare tumor that usually occur in the vulva and vagina, which is often diagnosed as Bartholin's cyst, vulvar cyst, myoma and unspecified complex tumor. Action in the form of total excision of tumor tissue gives a low recurrence.
 Keywords : Cervical angiofibroma, cervical tumor

Weltersia obscura, a new slug from the island of Montecristo (Tuscan Archipelago, Italy): a hitherto undiscovered endemic or a recent alien? (Mollusca, Pulmonata, Limacidae)

Unexpectedly, an unknown limacid slug was found in damp meadows and granite trails on the western side of Montecristo, a small island of the Tuscan Archipelago (N Tyrrhenian Sea, Italy), the malacofauna of which has been extensively studied in the last 50 years. It is distinguished from all other anatomically studied limacid species: its duct of the bursa copulatrix joins to the female distal genitalia while in all other limacids except Limacus flavus, it joins to the penis (or the genital atrium). Several other features distinguish the Montecristo slug from L. flavus: body colour, structure of ovispermiduct and free oviduct (with a peculiar sphincter in the new slug), internal structure of the penis and female distal genitalia. Analysis of the nucleotide sequences of several mitochondrial (COI, 16S rDNA) and nuclear (ITS2, 28S rDNA) gene fragments supported the assignation of the Montecristo slug to the family Limacidae, but also its distinction from all molecularly characterized species from the genera Limax, Ambigolimax, Bielzia, Lehmannia, Limacus and Malacolimax. Therefore we decided to describe it within a new genus as Weltersia obscura sp. nov. The origin of this slug is obscure – it is not clear if it is an endemic species overlooked in previous field studies or an alien species introduced to the island very recently. http://zoobank.org/urn:lsid:zoobank.org:act:0C5A2CC2-A94D-4B1D-8DF9-04FA54374E93: http://zoobank.org/urn:lsid:zoobank.org:act:0C6E4F69-E3E3-494F-BC1E-F7F49E9B529F

The introduced terrestrial slugs Ambigolimax nyctelius (Bourguignat, 1861) and Ambigolimax valentianus (Férussac, 1821) (Gastropoda: Limacidae) in California, with a discussion of taxonomy, systematics, and discovery by citizen science

ABSTRACTAmbigolimax valentianus and Ambigolimax nyctelius are synanthropic terrestrial slugs that have been dispersed widely by human activity. Herein, these species are reported from Los Angeles County, California, as a result of contributions to SLIME (Snails and Slugs Living in Metropolitan Environments), a citizen science project initiated by the Natural History Museum of Los Angeles County and hosted online by iNaturalist. Importantly, collected specimens and specimen data of A. nyctelius are the first of this species in California and the first records to document it in North America since 1960. Species identifications of A. valentianus and A. nyctelius, which are phenotypically similar, were made by examination of specimens’ distal genitalia and analysis of their mtDNA barcoding gene, COI (A. nyctelius, n = 18 and A. valentianus, n = 11). Slug radulae and jaws were examined and are figured, but were not diagnostic to species. Phylogenetic analyses of COI haplotypes from both Ambigolimax species and six other limacids resolve A. nyctelius and A. valentianus as monophyletic sister taxa. However, morphological and molecular data from taxa not included in this study are needed to substantiate this relationship and inform a revision of at least 10 genera in the family Limacidae. Inconsistencies in the literature regarding the year of Férussac’s species description of A. valentianus (as Limax valentianus) are also discussed and resolved.

How can two soft bodied animals be precisely connected? a miniature quick-connect system in the slugs, Arion lusitanicus and Arion rufus.

Among stylommatophoran gastropods, many species have simplified or reduced their copulatory organs, for example, within the Arionidae, many species lack penes. In this study, I ask two questions 1) How are soft bodied slugs which do not possess a penis connected during copulation? and 2) Is there a mechanical isolating barrier between related sympatric slug species? Observations on the mating behavior and the functional morphology of the distal genital apparatus were made in a mixed population of Arion lusitanicus and Arion rufus. The investigated Arion species exhibit an elaborate copulation process with a quick genital coupling. Prior to full eversion of the distal genitalia, the genital coupling proceeds inside the atrium cavity of one of the partners. This is in contrast to the symmetrical mutual eversion in penis-bearing species. The donor-recipient channels are tightly connected to one after another and fit precisely. During copulation, the jelly-coated spermatophore of the donor is pressed out into the connected channel of the partner, where it is implanted only with its frontal part. In the field, successful interspecific matings in terms of spermatophore transfer were rarely observed. The observations presented indicate a mechanical barrier which may profoundly influence the intraspecific and interspecific mating success.

Descripción de un nuevo limácido de Menorca (Islas Baleares): Gigantomilax (Vitrinoides) benjaminus sp. n. (Gastropoda, Pulmonata)

We describe a new endemic limacid slug, Gigantomilax (Vitrinoides) benjaminus n. sp. and we compare it with the nearest species, particularly with Gigantomilax (V.) majoricensis, another Balearic endemism. Characteristic features of this new species include its small size, translucid and smooth body, and totally grey dorsum with no bands or spots. The reproductive system shows a well developed vas deferens surrounded by the distal part of prostatic gland, a thin penial retractor muscle, swollen prostate and small distal genitalia. The recent redescription of Limax majoricensis by Wiktor et al. (2007) is discussed and we consider that these authors refer to G. benjaminus n. sp., and so we dessign the neotype of Gigantomilax (V.) majoricensis.

On a new species of Isomeria Beck and redescription of species of Labyrinthus Beck from South America (Gastropoda: Stylommatophora: Camaenidae)

The Camaenid genera Labyrinthus Beck, 1837 and Isomeria Beck, 1837 are mainly distributed in northern South America. Current anatomical information available for both genera is scarce, particularly that concerning Isomeria species. The morphology of the pallial organs, genital and digestive systems of three species of Labyrinthus [L. subplanatus (Petit, 1843), L. dunkeri (Pfeiffer, 1852), L. tarapotoensis Moricand, 1858] and a new species of Isomeria are described. The morphology of hooked denticles that topped wall ridges inside penis and vagina in some species of Labyrinthus and in Isomeria are species-specific characters, differing in shape and size. These structures were not sufficiently studied either in Isomeria or in Labyrinthus and are absent in all anatomically studied species of Solaropsis Beck, 1837, their sister genus. The presence of a bursa copulatrix sac reflexed over its duct is a character shared by all Labyrinthus species in which soft anatomy is known, and it was identified as a synapomorphy in a published phylogeny. Isomeria awa. n.sp. differs from other species of the genus mainly in shell morphology and characters of the distal genitalia. The presence of a stimulator-like structure in the vagina as well as the presence of a glandular pouch in the vagina are diagnostic characters of this new species, not present in the closely Camaenid related genera.

Arion Distinctus Mabille, 1868 (Gastropoda: Pilmonata: Arionidae) in Lithuania

New data on the spreading of Arion distinctus Mabille, 1868 as a new species in the Lithuanian fauna are presented. The analysis of the literature data shows that A. hortensis (usually confused with A. distinctus) is absent in Lithuania. This paper contains a description of two forms of A. distinctus (form A – with tripartite oviduct; form B – with bipartite oviduct) and also illustrations of this species. Significant differences in the body length between the two forms (one-way ANOVA: df = 76; F = 44, 27; p < 0.0001) were found. The occurrence of spermatophores in slugs (n = 7) of form B suggests that young slugs (up to 13–14 mm in body length – form A) function as males, while those of form B – as females. Our observations allowed us to assume that different forms of the distal genitalia change during onthogenesis, and this process is connected with a reciprocal outcrossing. In general, our hypothesis needs more investigations – a practical study of reproduction behaviour.

The perivaginal gland in Oxychilus (Drouetia) atlanticus (Morelet & Drouët, 1857) (Pulmonata: Zonitidae): a histological and histochemical approach

Summary The perivaginal gland of Oxychilus atlanticus presents two different types of secretory cells. They have voluminous cell bodies, placed externally with respect to the muscular wall of the vagina, and release their secretions into the lumen of the vagina through very long necks. The PVG1 secretory cells are the larger ones and are placed in the outermost layer of the gland, while the PVG2 does not reach the outer surface of the gland, outlying the muscular layer of the vagina. The PVG1 secretions are composed primarily of proteins. The main components of the PVG2 secretions are mucopolysaccharides and calcium. The possible function of each one of these two cells in the formation of the egg shell, in the stimulatory process, in sperm activation, or in the lubrication and protection of the different organs of the distal genitalia, are discussed.

Variation of distal genitalia in the simultaneously hermaphroditic land snail Arianta arbustorum (Pulmonata, Stylommatophora) caused by sexual selection?

The most likely explanation for genitalic extravagance may be sexual selection acting either before, during, or after copulation. In promiscuous species, the intensity of postmating sexual selection may be a function of population density. In this study we examined the variability of the distal genitalia involved in spermatophore production, reception and manipulation of 113 adult individuals of the simultaneously hermaphroditic land snail Arianta arbustorum (L.) from six natural populations in the Eastern Alps (Gesause, Austria). We investigated the hypothesis that these genitalia increase in relation to shell size with increasing population density (range: 0.9 to 39.8 individuals/m2) and expected a higher variance of the genitalia compared to shell dimensions due to sexual selection. Genitalic size was unexpectedly inversely related to population density, probably due to increased inhibitory effects of snail mucus. Patterns of variation of female and male characters did not differ. Coefficients of variation of the genitalia were significantly higher than those of the shell dimensions as predicted. This was due to a higher dispersion around the regression lines rather than higher allometric values. However, the influence of sexual selection on genitalic size and variance cannot be unambiguously determined. We discuss different scenarios emphasizing the importance of sexual selection to differing degrees and conclude that sexual selection has probably played only a minor role.

Variation of distal genitalia in the simultaneously hermaphroditic land snail Arianta arbustorum (Pulmonata, Stylommatophora) caused by sexual selection?

The most likely explanation for genitalic extravagance may be sexual selection acting either before, during, or after copulation. In promiscuous species, the intensity of postmating sexual selection may be a function of population density. In this study we examined the variability of the distal genitalia involved in spermatophore production, reception and manipulation of 113 adult individuals of the simultaneously hermaphroditic land snail Arianta arbustorum (L.) from six natural populations in the Eastern Alps (Gesäuse, Austria). We investigated the hypothesis that these genitalia increase in relation to shell size with increasing population density (range: 0.9 to 39.8 individuals/m2) and expected a higher variance of the genitalia compared to shell dimensions due to sexual selection. Genitalic size was unexpectedly inversely related to population density, probably due to increased inhibitory effects of snail mucus. Patterns of variation of female and male characters did not differ. Coefficients of variation of the genitalia were significantly higher than those of the shell dimensions as predicted. This was due to a higher dispersion around the regression lines rather than higher allometric values. However, the influence of sexual selection on genitalic size and variance cannot be unambiguously determined. We discuss different scenarios emphasizing the importance of sexual selection to differing degrees and conclude that sexual selection has probably played only a minor role.

Snail sperm production characteristics vary with sperm competition risk

Sperm competition is widespread and influences both male investment in spermatogenic tissue and ejaculate characteristics. Sperm competition models assume trade-offs between sperm size and number, although such trade-offs may be difficult to detect. This study examines the effects of sperm competition risk on the sperm production characteristics of the freshwater snail Viviparus ater. In this prosobranch, females mate frequently and store sperm, generating sperm competition. Males produce two sperm morphs, fertile eupyrene sperm and non-fertilizing oligopyrene sperm. Non-fertilizing sperm may play a role in sperm competition and therefore, like fertilizing sperm, the number produced could vary relative to sperm competition risk. In addition, trade-offs between sperm number and sperm size may be expected. We manipulated the sex ratio of sexually mature snails and found the presence of rivals affected the ratio of oligopyrene/eupyrene sperm males produced. In experimental and natural populations, the number of oligopyrene sperm produced, but not the number of eupyrene sperm, was significantly higher when the sex ratio was male biased. Testis mass did not vary between experimental treatments. We also found a negative relationship between the number and size of oligopyrene sperm produced, which is consistent with evolutionary models of sperm competition, and is, to our knowledge, the first intraspecific demonstration of a trade-off between these traits.

Geographic variation of distal genitalia in the landsnail Helix aspersa (Mollusca: Gastropoda)

Intraspecific differentiation in Helix aspersa Müller, which essentially occurred in North Africa, was until now investigated using only conchological and biochemical features. In this study, 972 specimens were scored for 10 metric characters (nine describing the terminal genitalia, one which represents the shell size) in order to complement our knowledge of the geographic patterns of divergence between populations from the whole natural area of the species. Multivariate analyses, involving principal components and discriminant functions, emphasized the high degree of differentiation in Maghreb (east versus west pattern) and indicated that the most reliable anatomical features to distinguish individuals, which generally have a giant size in North Africa, were the penis and diverticulum (to a lesser extent, flagellum) lengths. Thus, snails from eastern Maghreb were characterized by the smallest distal genitalia, especially a short diverticulum, although their shell size was far larger than that of European snails. This reduction was less perceptible in specimens from west Maghreb and, when present, concerned only some organs; penis length, not affected by this decrease, became then an important factor of discrimination in Maghreb. Moreover, it seemed that a large part of anatomical divergence between European and north‐western African populations was only attributable to a difference in shell size (larger snails with larger genitalia), whereas isolation of populations from eastern Maghreb was based on independent changes, involving different allometric relations between terminal genitalia and shell size. Furthermore, this phenomenon was observed in colonies from north‐western Greece, which were also close to some populations from east Maghreb on the basis of allozyme data; such results would suggest exchanges between both areas.

Observations on distal genitalia and mating activity in three conchologically distinct forms of the land snail Helix aspersa Müller

Observations on distal genitalia and mating activity in three conchologically distinct forms of the land snail <i>Helix aspersa</i> Müller

Differentiation of large arionid slugs (Mollusca, Pulmonata) using ligula morphology

A study of the ligula (a holdfast/stimulatory device associated with the distal genitalia) in the species aggregates Arion ater and A. lusitanicus, common in NW Europe, suggests that examination of this organ may permit rapid and reliable differentiation to the sub‐specific level. This study describes the ligula and its taxon‐specific characteristics, illustrated by three‐dimensional stereo photographs, which clearly reveal its structure and can be readily compared with dissected material. The bizarre and intricate variations some taxa exhibit in the form of this organ are interpreted in terms of mating behaviour.

An investigation of the status of the terrestrial slugs Arion ater ater (L.) and Arion ater rufus (L.) (Mollusca, Gastropoda, Pulmonata) in Britain

Three types of evidence, variation in external coloration and patterning. characters of the distal genitalia and biochemical variation, were used to determine if A. a. ater and A. u. rufus could be recognized in Britain. From these studies it was possible to recognize the two taxa, but the variation of the morphological characters was continuous between them. The range of variation, in particular that of the distal genitalia of A. a. ater, was much wider than indicated by previous studies. The biochemical results from the use of zone electrophoresis and staining for non‐specific esterases indicated that there was a high level of similarity between the taxa. It was not possible to determine whether the continuity in the variation resulted from hybridization or an overlap between two separate ranges. Consequently, although the results agreed with A. ater being two subspecies, more work is needed both in Britain and on the Continent to extend these observations and to determine the status of the two taxa.

Observations on variation in body coloration and patterning inLimax flavus LandLimax pseudoflavusEvans

Summary L. flavus and L. pseudoflavus can be distinguished and separated by the differences in the patterning of the external body coloration. The light coloration was expressed as small speckles in L. flavus causing the animals to have a dusky appearance and in L. pseudoflavus of blotches causing a mottled appearance. The two species overlapped in the range of coloration although L. pseudoflavus from Ireland tended to be darker and greener than L. flavus. In L. flavus the juvenile keel stripe persisted longer than in L. pseudoflavus and could persist, in some animals, until they were a third to a half, grown. Coloration could be affected by keeping animals in the laboratory: L. pseudoflavus originating from material collected from Ireland became much darker than the original material, with a wider range of mottling. Despite the two species having much greater similarity in external appearance than originally reported, there was no overlap in the diagnostic characters of the distal genitalia.