Penis Papilla Research Articles

Two New Species of Freshwater Planarian (Platyhelminthes, Tricladida, Dugesiidae, Dugesia) from Southern China Exhibit Unusual Karyotypes, with a Discussion on Reproduction in Aneuploid Species

Two new species of the genus Dugesia from Southern China are described by applying an integrative approach, including morphological, karyological, histological, and molecular information. In the molecular phylogenetic tree, the two new species, Dugesia pendula Chen & Dong, sp. nov. and Dugesia musculosa Chen & Dong, sp. nov., fall into an Eastern Palearctic/Oriental clade and an Oriental/Australasian clade, respectively, while sharing only a rather distant relationship. The separate specific status of the two new species is supported also by their genetic distances. Dugesia pendula is characterized by the following features: symmetrical openings of the oviducts into the bursal canal, a duct between seminal vesicle and diaphragm, small diaphragm, dorsally located seminal vesicle, a penis papilla suspended from the dorsal wall of the male atrium, and mixoploid karyotype with diploid complements of 2n=2x=14+0−1 B-chromosome and triploid complements of 2n=3x=21+0−1 B-chromosome, with all chromosomes being metacentric. Dugesia musculosa is characterized by the following features: asymmetrical openings of the oviducts into the bursal canal; a ventrally displaced ejaculatory duct with a terminal opening; two diaphragms; a bursal canal provided with a strong, thick layer of circular muscle, which extends from the copulatory bursa to the common atrium and gonoduct; the left vas deferens opening at the midlateral wall of the seminal vesicle, while the right sperm duct opens at the dorsolateral wall of the seminal vesicle; and karyotype consisting of complicated diploid and aneuploid mosaicism, with diploid complements of 2n=2x=16 and 2n=2x=16−17th-18th, with all chromosomes being metacentric. The uncommon karyotypes, combined with the asexual reproduction of aneuploid animals, are evaluated in the context of the relationship between ploidy levels and reproductive modalities in the genus Dugesia.

Integrative description of a new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from southern China, with its complete mitogenome and a biogeographic evaluation

A new species of freshwater flatworm of the genus Dugesia from Guangdong Province in China is described through an integrative approach, including molecular and morphological data, as well as mitochondrial genome analysis. The new species, Dugesia ancoraria Zhu & Wang, sp. nov., is characterised by: (a) a highly asymmetrical penis papilla, provided with a hunchback-like dorsal bump; (b) a short duct between seminal vesicle and ejaculatory duct; and (c) a postero-ventral course of the ejaculatory duct, which opens to the exterior at the subterminal, ventral part of the penis papilla. The molecular phylogenetic tree obtained from the concatenated dataset of four DNA markers (18S rDNA, ITS-1, 28S rDNA, COI) facilitated determination of the phylogenetic position of the new species, which shares a sister-group relationship with a small clade, comprising D. notogaea Sluys & Kawakatsu, 1998 from Australia and D. bengalensis Kawakatsu, 1983 from India. The circular mitogenome of the new species is 17,705 bp in length, including 12 protein coding genes, two ribosomal genes, and 22 transfer RNAs. Via analysis of gene order of mitochondrial genomes, the presently available pattern of mitochondrial gene rearrangement in the suborder Continenticola is discussed.

Integrative description of a new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Shennongjia, Central China.

A new species of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Xiangxi River, Shennongjia Forestry District, Hubei Province, China, is described on the basis of an integrative approach, involving morphology, and molecular systematics. The new species Dugesia saccaria A-T. Wang & Sluys, sp. nov. is characterized by the following features: a dumb-bell-shaped, muscularized hump located just anterior to the knee-shaped bend in the bursal canal; a ventrally displaced ejaculatory duct, which, however, opens terminally through the dorsal portion of the blunt tip of the penis papilla; a ventrally located seminal vesicle, giving rise to a vertically running duct that eventually curves downwards to communicate with the ejaculatory duct via a small diaphragm; oviducts opening asymmetrically into the dorsal portion of the common atrium and at the knee-shaped part of the bursal canal. The phylogenetic position of the new species was determined using four molecular markers (18S rDNA; ITS-1; 28S rDNA; COI), which suggested that it groups with other species of Dugesia from the Australasian and Oriental biogeographical regions.

Theama japonica sp. nov., an Interstitial Polyclad Flatworm Showing a Wide Distribution along Japanese Coasts.

We establish a new interstitial polyclad species, Theama japonica sp. nov., based on specimens collected from coarse-sandy habitats in three Japanese main islands (Hokkaido, Honshu, and Shikoku) along the coasts of the Pacific Ocean and the Sea of Japan. Theama japonica is characterized by i) two pairs of cerebral eyespots and four to six precerebral eyespots; ii) eosinophilic secretion glands distributed in the distal half of the inner ventral part of the prostatic vesicle; iii) a conical penis papilla, bent up dorsally, with a sclerotized inner wall; iv) the prostatic sheath with an inner angular fold on the dorso-distal side; and v) the external cilia longer dorsally than ventrally. Partial sequences of the cytochrome c oxidase subunit I (COI) gene from 20 specimens collected at eight localities along Japanese coasts represented 19 haplotypes. The uncorrected p-distances among these COI haplotypes fell within intraspecific variations observed in other polyclads. A network analysis based on these COI haplotypes suggested a geographically non-cohesive genetic structure of the species, possibly indicating the species' high dispersibility. Molecular phylogenetic analyses based on a concatenated dataset of 18S and 28S rDNA sequences showed T. japonica formed a clade with other Theama species. The resulting tree also indicates that our new species is more closely related to Theama sp. from Colombia than species from Panama and Croatia.

<i>Corrigendum to</i>: Integrative taxonomy increases biodiversity knowledge of <i>Gusana</i> (Platyhelminthes, Tricladida, Geoplanidae) with the description of four new Chilean species

The Chilean land planarian genus <i>Gusana</i> (Platyhelminthes, Tricladida, Geoplaninae) currently comprises three species that were described in the 19th century. Four new species of the genus are described herein, namely <i>G. hualpensis</i> Carbayo, sp. nov., <i>G. lujanae</i> Almeida & Carbayo, sp. nov., <i>G. melipeucensis</i> Almeida & Carbayo, sp. nov. and <i>G. purensis</i> Bolonhezi, Almeida & Carbayo, sp. nov. An integrative taxonomy approach was adopted by combining morphological (anatomy, histology) and molecular (<i>COI</i> and <i>28S</i> genes) information. Additionally, the monophyletic status of <i>Gusana</i> is investigated and the species are delimited by a recently introduced molecular delimitation method based on pairwise genetic distances. All <i>Gusana</i> species are very similar in attributes such as body shape, dorsal colour pattern and internal organs, namely the pharynx and copulatory apparatus and only differ in the details. <i>Gusana</i> is retrieved as monophyletic and the molecular delimitation method recovered the same species recognised morphologically. A re-diagnosis of the genus and replacement of <i>G. lata</i> into <i>Pseudogeoplana</i> are also proposed. A new role of the penis papilla is also suggested based on the spermatophore found in <i>Gusana lujanae</i>.

Biogeography and diversification of the freshwater planarian Crenobia alpina sensu lato (Platyhelminthes, Tricladida): A synthetic review

Through an in-depth study of the literature, as well as some other sources of information, geographical distribution maps of the various taxa of the European freshwater planarian genus Crenobia (Platyhelminthes, Tricladida) are provided, which document their records and distributional ranges in a detail that was previously unavailable. The genus Crenobia ranges across Northern, Western, Southern, and Eastern Europe, including several islands in the Mediterranean region, but is absent from a major part of the Iberian Peninsula; it is distributed also in Turkey. The chromosome portrait of Crenobia is complex, as it exhibits chromosome numbers that are multiples of 7, such as 28, 35, 42, 56, and 63. Sexually reproducing populations are tetraploid or hexaploid, while asexually reproducing populations exhibit high chromosome numbers. All taxa of Crenobia are stenothermic, cold-loving species. Although historical biogeographic scenarios interpreting the taxonomic diversification of the genus as being the result of the vicissitudes of the Last Ice Age are still captivating, it may be the case that the genus already diversified 6-20 million years ago. The paper sketches in some detail the anatomy of the copulatory complex of the various taxa. Previously, it went unnoticed that in two of the taxa (Crenobia alpina and C. anophthalma) the two sperm ducts have different, asymmetrical trajectories. Further, it was largely undocumented that in several taxa the sperm ducts exhibit a pronounced recurvature, as well as a dorsal loop before entering the penis papilla. Neither did previous studies document that in C. montenigrina the mouth opening is not located at the most posterior end of the pharyngeal pocket, but has shifted anteriad for some distance. Polypharyngy is a stable, species-specific character, with C. montenigrina usually exhibiting 11-17 pharynges, while C. anophthalma has never more than three pharynges. Different views have been expressed on the taxonomic status of several geographic and anatomical forms of Crenobia. It is shown here that Crenobia comprises five, well-defined full species, viz., C. alpina, C. corsica, C. montenigrina, C. anophthalma, and C. bathycola.

Two new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the subtropical monsoon region in Southern China, with a discussion on reproductive modalities

BackgroundFreshwater planarians of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) are distributed in a major part of the Old World and Australia, although until recently only very few species were known from China.ResultsTwo new species of Dugesia from Southern China are described on the basis of an integrative taxonomic approach. BI and ML phylogenetic trees based on the independent genes and on the concatenated dataset had similar topologies, only differing in some nodes that were weakly supported. Phylogenetic trees based on the concatenated dataset revealed that D. adunca Chen & Sluys, sp. nov. and D. tumida Chen & Sluys, sp. nov. are not closely related and belong to different clades. The two new species occupy separate long branches with high support values and, thus, are well-differentiated from their congeners. Separate species status of D. adunca and D. tumida is supported also by the genetic distances between the species included in our analysis, albeit that COI distances varied greatly among species. Dugesia adunca from Guangxi Province is characterized by the following features: living mature animals rather small; asymmetrical openings of the oviducts into the bursal canal; penis papilla with shape of an aquiline bill, albeit with a blunt tip; asymmetrical penis papilla, with a large antero-dorsal lip and a much smaller ventro-posterior lip; very large seminal vesicle, provided with trabeculae; small diaphragm; mixoploid karyotype with diploid complements of 2n = 2x = 16 and triploid complements of 2n = 3x = 24, with all chromosomes being metacentric. Dugesia tumida from Guangdong Province is characterized by a penis papilla provided with a large, symmetrical penial valve from the middle of which arises the small, distal section of the papilla; a duct intercalated between the seminal vesicle and the small diaphragm; ventrally displaced ejaculatory duct curving upwards before opening to the exterior; penis papilla highly asymmetrical, having a slim and long ventral portion and a short and stubby dorsal part; vasa deferentia separately opening into antero-dorsal portion of seminal vesicle; oviducts openings symmetrically into ventral portion of the bursal canal, near its opening into the atrium; mixoploid karyotype, with diploid chromosome portraits of 2n = 2x = 16, and triploid complements of 2n = 3x = 24, with all chromosomes being metacentric. In the context of the various kinds of mixoploidy and the sexualization of specimens, reproductive modalities within the genus Dugesia are shortly discussed.ConclusionMolecular, morphological, and karyological markers show that the two populations examined represent members of the genus Dugesia and constitute two new, distinct species.

A new genus of land planarian (Platyhelminthes, Geoplanidae) for a new ‘blind’ species

The morphological and molecular (mitochondrial cytochrome c oxidase subunit I, COI) characterization of a new species of the subfamily Geoplaninae (Geoplanidae) supports the erection of a new genus, Anophthalmoplana gen. nov. The most remarkable feature of Anophthalmoplana horticola sp. nov. is the absence of eyes, a feature so far only recorded in one species of Geoplaninae, Geobia subterranea. Other features of the species are: a narrow, ribbon-shaped body; a gonopore near the posterior tip; a creeping sole almost as wide as body width; cylindrical pharynx; voluminous extrabulbar prostatic vesicle; protrusible penis papilla occupying the whole male atrium; a common ovovitelline duct dorsal to the female atrium; the atrium being lined by an epithelium with a stratified appearance. Based on the mtDNA phylogeny, the specimens studied here form a separate clade from the genus Geobia, thus contradicting its inclusion in this genus or any other of the subfamily Geoplaninae. These results reinforce the morphological differences observed, regarding internal anatomy, from Geobia and other members of Geoplaninae. http://zoobank.org/urn:lsid:zoobank.org:pub:317A4055-BCC8-4B89-A9DC-F96F98E803A5

Integrative taxonomy increases biodiversity knowledge of Gusana (Platyhelminthes, Tricladida, Geoplanidae) with the description of four new Chilean species

The Chilean land planarian genus Gusana (Platyhelminthes, Tricladida, Geoplaninae) currently comprises three species that were described in the 19th century. Four new species of the genus are described herein, namely G. hualpensis Carbayo, sp. nov., G. lujanae Almeida & Carbayo, sp. nov., G. melipeucensis Almeida & Carbayo, sp. nov. and G. purensis Bolonhezi, Almeida & Carbayo, sp. nov. An integrative taxonomy approach was adopted by combining morphological (anatomy, histology) and molecular (COI and 28S genes) information. Additionally, the monophyletic status of Gusana is investigated and the species are delimited by a recently introduced molecular delimitation method based on pairwise genetic distances. All Gusana species are very similar in attributes such as body shape, dorsal colour pattern and internal organs, namely the pharynx and copulatory apparatus and only differ in the details. Gusana is retrieved as monophyletic and the molecular delimitation method recovered the same species recognised morphologically. A re-diagnosis of the genus and replacement of G. lata into Pseudogeoplana are also proposed. A new role of the penis papilla is also suggested based on the spermatophore found in Gusana lujanae.

Integrative taxonomy unveils a new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the southern portion of the Taihang Mountains in northern China, with the description of its complete mitogenome and an exploratory analysis of mitochondrial gene order as a taxonomic character.

A new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from northern China is described on the basis of an integrative approach, involving morphology, karyology, histology, molecular distance, molecular phylogeny, and mitochondrial gene order. Here, we present the complete mitogenome of the new species Dugesia constrictiva Chen & Dong, sp. nov. This new species is mainly characterized by the presence of the following features: asymmetrical openings of the oviducts; large, cuboidal copulatory bursa; vasa deferentia opening through the ventro-lateral wall of the seminal vesicle; laterally compressed seminal vesicle; ventrally displaced ejaculatory duct, opening at the blunt tip of the penis papilla; long duct intercalated between seminal vesicle and diaphragm; chromosome complement diploid, with 16 metacentric chromosomes; mitochondrial gene order as follows: cox1-E-nad6-nad5-S2-D-R-cox3-I-Q-K-atp6-V-nad1-W-cox2-P-nad3-A-nad2-M-H-F-rrnS-L1-Y-G-S1-rrnL-L2-T-atp8-C-N-cob-nad4l-nad4. In triclads, mitochondrial gene order is considerably conserved between freshwater planarians and land flatworms, whereas it is variable between marine planarians and both freshwater and land flatworms. The secondary structures of tRNAs are all equipped with 4 arms, excepting tRNA S1 and tRNA S2, which lack the D arm and have excessively enlarged loops. Numerous transpositions of tRNA are present between D. constrictiva and its congeners. Mitochondrial gene arrangements may form a new, additional tool for taxonomic studies. The phylogenetic tree based on analysis of the mitochondrial genome basically corroborates current classification of the higher taxa of planarian flatworms.

Two new species of the marine flatworm Pericelis (Platyhelminthes: Polycladida) from southwestern Japan with an amendment of the generic diagnosis based on phylogenetic inference

ABSTRACT We describe two new polyclad species, Pericelis lactea sp. nov. and P. maculosa sp. nov., from Japan. Pericelis lactea sp. nov. is characterized by (i) a translucent white body, (ii) the male and female gonopores opening separately and (iii) a conical penis papilla. Pericelis maculosa sp. nov. is distinguished from its other congeners by (i) a translucent white body with white to light blue dots all over the dorsal surface and brown speckles around the pharyngeal area, (ii) the male and female gonopores opening separately and (iii) a long, cylindrical penis papilla. We also infer the phylogeny of 10 species of Diposthidae using a concatenated dataset comprising partial 18S and 28S rDNA sequences from the two new and eight other known species. Our results showed Marcusia alba Cuadrado, Rodríguez, Moro, Grande and Noreña, 2021 was nested within a clade comprising the seven Pericelis species included in the analysis. These findings support the prior synonymization of Marcusia with Pericelis based on the morphology, hence we transferred M. alba to Pericelis. We modified the diagnosis of Pericelis to accommodate such species as P. alba comb. nov. and P. lactea sp. nov., in which marginal eyespots are distributed only anteriorly. http://zoobank.org/urn:lsid:zoobank.org:pub:14906638-970B-4C67-81EE-E6111F98F77F

Two new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the tropical monsoon forest in southern China.

Two new species of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from the tropical monsoon forest in southern China are described on the basis of an integrative taxonomic study involving morphology, karyology, histology, and molecular analyses. The new species Dugesiacircumcisa Chen & Dong, sp. nov. is characterised by asymmetrical openings of the oviducts; right vas deferens opening at anterior portion of the seminal vesicle and the left one opening at mid-lateral portion of the seminal vesicle; two diaphragms in ejaculatory duct, the latter being ventrally displaced and opening at the tip of the penis papilla, which is provided with a nozzle; wide duct connecting male atrium and common atrium; chromosome complement triploid with 24 metacentric chromosomes. The other new species, Dugesiaverrucula Chen & Dong, sp. nov., is characterised by the large size of the living worm, usually exceeding 3.5 cm in length; asymmetrical openings of the oviducts; subterminal opening of ventrally displaced ejaculatory duct; vasa deferentia symmetrically opening into the postero-lateral portion of the seminal vesicle; well-developed duct between the seminal vesicle and diaphragm; single dorsal bump near the root of the penis papilla; bursal canal with pleated wall and spacious posterior section; unstalked cocoons; chromosome complement diploid with 16 metacentric chromosomes. Inter-specific molecular distances and their positions in the phylogenetic tree reveal that D.circumcisa and D.verrucula are clearly separated from their congeners.

Molecular phylogenetic and morphological evidence reveal a rare limacoid snail genus, Khmerquantula gen. nov. (Eupulmonata: Dyakiidae) from Cambodia

An enigmatic land snail species restricted to the karst ecosystem in southern Cambodia and formerly placed in the family Ariophantidae is now reclassified into the family Dyakiidae. Its current systematic position is based on morpho-anatomical characters combined with a molecular phylogeny based on two partial mitochondrial markers (COI and 16S rDNA) and a nuclear gene fragment (28S rDNA). Our results indicate that Khmerquantula gen. nov. is a member of the Dyakiidae with very strong support from both morphological and molecular phylogenetic analyses. The diagnostic characters of this new genus and new species, Khmerquantula leipo are a dextral shell with a well-polished surface, animal with only three dorsal lobes, and reproductive organ without penial verge and amatorial organ papilla. This finding adds a new taxon to current biodiversity and illustrates the growing knowledge of the endemic malacofauna in Cambodia. http://zoobank.org/urn:lsid:zoobank.org:pub:5E5201B1-5BE6-452F-8D1A-B292DBA4AC25 http://zoobank.org/urn:lsid:zoobank.org:act:0D0414A4-FDA5-4E59-BAFE-1E1B68F37E36 http://zoobank.org/urn:lsid:zoobank.org:act:E08633F4-F5E1-4D99-8C70-252DF349C39A

A new species of terrestrial planarian of the genus Microplana (Platyhelminthes: Turbellaria; Tricladida: Continenticola) from Yorkshire, United Kingdom; with a discussion of Microplana humicola Vejdovsky 1890

Two mostly white terrestrial planarians, about 7 mm long, found in a garden in Yorkshire, UK, are described. They have a single pair of eyes and both specimens are fully mature, with a single pair of ovaries, several testes, a conical penis papilla and a genito-intestinal duct, characters of the genus Microplana, but differ in color and size from other species of the genus and are described as Microplana edwardsi sp. nov.

Integrative descriptions of two new species of Dugesia from Hainan Island, China (Platyhelminthes, Tricladida, Dugesiidae).

Two new species of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Hainan Island of China are described on the basis of morphological, karyological and molecular data. Dugesia semiglobosa Chen & Dong, sp. nov. is mainly characterized by a hemispherical, asymmetrical penis papilla with ventrally displaced ejaculatory duct opening terminally at tip of penis papilla; vasa deferentia separately opening into mid-dorsal portion of intrabulbar seminal vesicle; two diaphragms in the ejaculatory duct; copulatory bursa formed by expansion of bursal canal, lined with complex stratified epithelium, which projects through opening in bursa towards intestine, without having open communication with the gut; mixoploid chromosome complement diploid (2n = 16) and triploid (3n = 24), with metacentric chromosomes. Dugesia majuscula Chen & Dong, sp. nov. is mainly characterized by oviducts opening asymmetrically into female reproductive system; hyperplasic ovaries; expanded posterior section of bursal canal; vasa deferentia separately opening into mid-dorsal portion of seminal vesicle; asymmetrical penis papilla due to ventral course of ejaculatory duct, which has subterminal and dorsal opening at tip papilla; mixoploid chromosome complement diploid (2n = 16) and triploid (3n = 24); chromosomes metacentric. Apart from their anatomy, separate species status of the two new species is supported also by their genetic distances and by their positions in the phylogenetic tree. The sexualization process may have been induced by the lower temperatures, in comparison with their natural habitat, under which the worms were cultured in the laboratory.

Taxonomy and phylogeny of Koinocystididae (Platyhelminthes, Kalyptorhynchia), with the description of three new genera and twelve new species.

The taxon Koinocystididae is the third most species-rich family within Eukalyptorhynchia. However, its diversity and phylogeny have been largely neglected in former studies. We introduce three new genera and twelve new species of Koinocystididae including Simplexcystis asymmetrica gen. n. sp. n., Galapagetula cubensis sp. n., eight species of Reinhardorhynchus gen. n. and two species of Itaipusa. This raises the total number of species within Koinocystididae from 51 to 63. We also report on new distribution records for six known species: I. divae (Cuba, Panama and New Caledonia), I. karlingi (Sardinia and Lanzarote), Reinhardorhynchus riegeri comb. n. (Cuba), R. ruffinjonesi comb. n. (Cuba and Panama), Utelga heinckei (Cuba and Lanzarote), and U. pseudoheinckei (Sardinia). Simplexcystis asymmetrica gen. n. sp. n. is characterised by a male duct running eccentrically through the copulatory bulb, lack of any hard structures in the male system, lack of a bursa, and the fact that the epithelia of the female, the male, and part of the common atrium are covered by a brush border. Galapagetula cubensis sp. n. has a caudal gonopore, a divisa-type copulatory bulb with an unarmed penis papilla, and a female duct without a sphincter. The new species of Itaipusa and Reinhardorhynchus gen. n. differ from their congeners in the detailed structure of the copulatory bulb and especially the hard structures associated with it. In a molecular phylogenetic analysis based on all available 18S and 28S rDNA sequences of koinocystidids, we found support for the monophyly of the family and the genus Utelga Marcus, 1949. The genus Itaipusa is not monophyletic in that I. sinensis forms a clade with Rhinolasius dillonicus, while other species of Itaipusa that have a copulatory bulb armed with hooks form a clade together with Sekerana stolzi. As the type species of Itaipusa (I. divae) is in neither of these clades, we erected a new genus for I. sinensis (Koinogladius gen. n.) and one for species of Itaipusa having a hook-bearing copulatory bulb (Reinhardorhynchus gen. n.), respectively. Whether the remaining species of Itaipusa form a monophylum remains uncertain.

Seeing the true colours: three new species of

The genus Obama Carbayo, Álvarez-Presas, Olivares, Marques, Froehlich & Riutort, 2013 currently comprises 41 species, most of them from Brazilian rainforests. This study describes three new species, viz. Obama autumna sp. nov., Obama leticiae sp. nov. and Obama aureolineata sp. nov., from remnants of Mixed Ombrophilous Forest in southern Brazil, based on an integrative approach and analyses their relationships within the genus. Obama autumna and O. aureolineata show distinctive colour patterns, contrasting yellow and black, which is unusual in species of the genus. The three species can be easily distinguished from their congeners by their external features and a combination of anatomical characteristics, such as the pharyngeal shape, shape and arrangement of the prostatic vesicle and anatomy of the penis papilla. The morphological hypotheses are corroborated by three species delimitation methods (ABGD, PTP and GMYC) and by phylogenetic analysis of the cytochrome c oxidase subunit I gene using maximum likelihood estimation and Bayesian inference. Furthermore, our phylogenetic analyses point out that Obama may be subdivided into three main clades, containing a variable number of well supported groups, the relationships of which remain unresolved. Obama autumna belongs to a distinct clade in relation to O. aureolineata and O. leticiae. Obama aureolineata belongs to one of the well supported groups, having a close relationship with O. apeva. Obama autumna may be more closely related to O. anthropophila and O. decidualis and O. leticiae to O. braunsi. However, the low nodal support does not allow the phylogenetic relationships of these species to be clearly established. We discuss morphological knowledge gaps in Obama, as well as issues regarding analyses based on molecular markers, which should be addressed to clarify relationships within the genus. urn:lsid:zoobank.org:pub:9EE7316D-F0BE-49EC-BBFD-5687952D6592

Redescription of Monacha pantanellii (De Stefani, 1879), a species endemic to the central Apennines, Italy (Gastropoda, Eupulmonata, Hygromiidae) by an integrative molecular and morphological approach.

Specimens obtained from ten populations of a Monacha species from the central Apennines were compared with six molecular lineages of Monacha cantiana s. l. (CAN-1, CAN-2, CAN-3, CAN-4, CAN-5, CAN-6) and two other Monacha species (M. cartusiana and M. parumcincta), treated as outgroup, by molecular (nucleotide sequences of two mitochondrial COI and 16S rDNA as well as two nuclear ITS2 and H3 gene fragments) and morphological (shell and genital anatomy) analysis. The results strongly suggest that these populations represent a separate species for which two names are available: the older Helix pantanellii De Stefani, 1879 and the junior M. ruffoi Giusti, 1973. The nucleotide sequences created well separated clades on each phylogenetic tree. Genital anatomy included several distinctive features concerning vaginal appendix, penis, penial papilla and flagellum; instead, shell characters only enabled them to be distinguished from M. cartusiana and M. parumcincta. Remarkably, populations of M. pantanellii show high morphological variability. Shell variability mainly concerns size, some populations having very small dimensions. Genital variability shows a more intricate pattern of all anatomical parts, being higher as regards the vagina and vaginal appendix. Despite this morphological variability, the K2P distance range of COI sequences between populations is narrow (0.2–4.5%), if we consider all but three of the 53 sequences obtained. This research confirmed that the species of Monacha and their molecularly distinguished lineages can only occasionally be recognised morphologically and that they have significant inter- and intra-population variability. The possibility of using an overall approach, including shell, genital and molecular evidence, was taken in order to establish a reliable taxonomic setting.

Three new Neotropical species and a new genus of land flatworms (Platyhelminthes, Geoplaninae)

Three new Neotropical land planarians (Platyhelminthes, Tricladida, Geoplaninae) from the Brazilian Atlantic forest are described. Obama apiguara Oliveira, Almeida & Carbayo sp. nov. presents glandular fossae opening through dorsal epithelium, a structure not documented previously among land flatworms. Paraba tata Bolonhezi, Lago-Barcia & Carbayo sp. nov., is characterized by a prostatic vesicle horizontal with an inconspicuous bifurcate portion, a penis papilla as long as male atrium and a female genital duct projected from the postero-dorsal section of the female atrium. The third new species is distinctive in the extraordinarily thick muscle surrounding the prostatic vesicle, a finger-shaped penis papilla, and a dilated female genital cavity. These attributes stands the species apart from all members of Geoplaninae and Piima ata Carbayo gen. et sp. nov. is proposed.

A new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from China, with an account on the histochemical structure of its major nervous system

By means of an integrated approach, including molecular, morphological, anatomical and histological data, we describe a new species of freshwater flatworm of the genus Dugesia from southwest China, representing the third species recorded for the country. Morphologically, the new species, Dugesia umbonata Song & Wang, sp. nov., is particularly characterised by the presence of a muscularised hump immediately antero-dorsally to a knee-shaped bend in its bursal canal and by an ejaculatory duct that opens subterminally through the dorsal side of the penis papilla. Four molecular datasets (18S rDNA; ITS-1; 28S rDNA; COI) facilitated determination of the phylogenetic position of the new species, which belongs to a clade comprising other species from the Australasian and Oriental regions. We also analysed the structure of its major nervous system by means of the acetylcholinesterase (AChE) histochemical method and compared these results with data available for three other species of Dugesia.