Phylogeography of Plectostylus Beck, 1837 (Gastropoda: Stylommatophora: Orthalicoidea): Origin and isolation of the Fray Jorge forest relicts in northern Chile

Among the questions surrounding the biogeographical history of the Chilean biota, none has gathered more interest than the origin of the Fray Jorge (FJ) forest relict and its biota. Inserted in a semi‐desert area, this forest enclave exists due to the existence of a very particular microclimate in this region. The age of the disjunction and the historical relationship between the FJ biota with the remaining components of South America are explained by two distinct, competing hypotheses: the first suggests that it would have become isolated during the climatic changes of the Paleogene/Neogene, while the second suggests that the isolation is a product of Quaternary glaciations. To discriminate between these competing hypotheses, we used DNA sequence phylogeny methods and molecular genetic dating to the study of a genus of land snails (Plectostylus) that occurs in the FJ relict and throughout Chile. The phylogeny shows a clear distinction between forest and arid clades, and each of these clades is formed by many geographically circumscribed populations. The FJ fragment snails form a clade that is sister to all other forest clades. The separation between the Fray Jorge clade and the other forest clades dates back to the Paleogene/Neogene. Our data suggest that the FJ forest is a relict from the forests that occupied that landscape during the Paleogene/Neogene and retreated due to the aridification of the region. We also observe that the current taxonomy of the Plectostylus genus must be re‐evaluated.     

Phylogeny and biogeography of the Vitrinidae (Gastropoda: Stylommatophora)

The phylogeny of the Vitrinidae is reconstructed in a cladistic analysis based on characters of the genitalia, the copulation behaviour and the radula. The genera with an atrial stimulator turned out to be the earliest branches of the Vitrinidae, whereas the genera with a glandula amatoria form a monophyletic, taxonomically apomorphic group. The differences between the proposed phylogeny and previous hypotheses are discussed. The ancestral areas of the Vitrinidae and its sister group, the limacoid slugs Boettgerillidae–Limacidae–Agriolimacidae, are estimated using weighted ancestral area analysis. The Vitrinidae and the limacoid slugs might have originated by a vicariance event between Central Europe and the Near East. © 2002 The Linnean Society of London. Zoological Journal of the Linnean Society , 2002, 134 , 347–358.     

Structural diversity of NADPH diaphorase-reactive enteral networks in Stylommatophora (Gastropoda, Pulmonata)

Abstract. In this work we investigated the involvement of putative nitric oxide (NO)-forming neurons in enteric plexuses of stylommatophoran gastropods. The nitric oxide synthase (NOS)-containing cells were detected by NADPH diaphorase (NADPHd) histochemistry in the entreral nervous systems of several stylommatophoran species (Achatinacea: Achatina fulica , Helicacea: Cepaea hortensis, Cepaea nemoralis, Discus rotundatus, Helicella obvia, Helix lucorum, Helix lutescens, Monachoides umbrosa, Trichia hispida, Zebrina detrita , Succineacea: Succinea putris , Vertiliginacea: Clausilia dubia , Zonitacea: Arion ater, Arion subfuscus, Limax maximus ). We detected the NO synthesis of isolated midintestinal segments by Griess's quantification of nitrite, one end product of NO. Effects of the NOS substrate L-arginine and the NOS inhibitor Nω-nitro-L-arginine (NOARG) were also tested on nitrite production. We found NADPHd-reactive neurons and extrinsic nerves with NADPHd-stained fibers within the myenteric and submucosal networks of the midintestine of investigated members of Helicacea, Succineacea, and Vertiliginacea families. These networks innervated the midintestinal musculature and several nerve cells of the myenteric and submucosal plexi. In investigated members of Achatinacea and Zonitacea, NADPHd-stained networks were not detectable within the digestive tract. Administration of 1 mM L-arginine elevated, whereas 2 mM of NOARG diminished, the nitrite levels of the NADPHd-stained networks containing midintestine in C. nemoralis and H. lucorum . Enteral NADPHd staining was not detected in A. ater and L. maximus , and the nitrite production was not affected by L-arginine. Our results indicate a possible, but evolutionarily not conserved, NO-mediated enteral transmission in stylommatophoran gastropods.     

Ultrastructure of spermatozoa in Orthalicidae (Mollusca,Gastropoda, Stylommatophora) and its systematic implications

Sperm morphology of orthalicid gastropods Clessinia pagoda, Spixia tucumanensis, Plagiodontes daedaleus (Odontostominae) and Drymaeus hygrohylaeus, D. poecilus, Bostryx stelzneri (Bulimulinae) are examined and described for the first time using transmission electron microscopy. Spermatozoa show the general characteristic of Pulmonata: an acrosomal vesicle, sperm nucleus helical, mitochondrial derivative forming a continuous sheath with paracrystalline material and coarse fibers associated with axonemal doublets. Features in the acrosomal complex and shape of the nucleus distinguish orthalicid sperms from other stylommatophoran. The acrosomal pedestal is traversed by fine striations in all species examined except in S. tucumanensis. The structure and thickness of the perinuclear sheath with a single or double layer of electron-dense material ensheathing the nuclear apex is characteristic of the group. The presence of a subnuclear ring in Drymaeus, Bostryx and Clessinia species is also reported. A data matrix of eleven species per 34 characters (16 sperm plus 18 anatomical and shell characters) from orthalicids plus other stylommatophoran and systellommatophoran representative species was constructed. Three cladistic analyses (sperm-based, anatomical-based and a combined sperm + anatomical-based) were performed to test the phylogenetic potential of sperm ultrastructure in orthalicid systematics and understand how sperm characters affect the topology and resolution of the obtained trees. Stylommatophora resulted in a monophyletic clade in the sperm-based and in the combined-character analysis. Orthalicidae is monophyletic only in the combined-character cladogram. Within Orthalicidae, Odontostominae is recovered as a monophyletic clade in all analyses, while Bulimulinae is paraphyletic in all trees except in the combined phylogeny. The present study and cladistic analyses performed support the hypothesis that characters on sperm ultrastructure are informative for stylommatophoran systematic and phylogenetic approaches, providing synapomorphies at familiar, subfamiliar and generic level.     

Annotated type catalogue of the Bulimulidae (Mollusca,Gastropoda, Orthalicoidea) in the Natural History Museum,London

The type status is described of 404 taxa classified within the family Bulimulidae (superfamily Orthalicoidea) and kept in the London museum. Lectotypes are designated for Bulimus aurifluus Pfeiffer, 1857; Otostomus bartletti H. Adams, 1867; Helix cactorum d’Orbigny, 1835; Bulimus caliginosus Reeve, 1849; Bulimus chemnitzioides Forbes, 1850; Bulimus cinereus Reeve, 1849; Helix cora d’Orbigny, 1835; Bulimus fallax Pfeiffer, 1853; Bulimus felix Pfeiffer, 1862; Bulimus fontainii d’Orbigny, 1838; Bulimus fourmiersi d’Orbigny, 1837; Bulimus (Mesembrinus) gealei H. Adams, 1867; Bulimus gruneri Pfeiffer, 1846; Bulimus humboldtii Reeve, 1849; Helix hygrohylaea d’Orbigny, 1835; Bulimus jussieui Pfeiffer, 1846; Bulimulus (Drymaeus) binominis lascellianus E.A. Smith, 1895; Helix lichnorum d’Orbigny, 1835; Bulimulus (Drymaeus) lucidus da Costa, 1898; Bulimus luridus Pfeiffer, 1863; Bulimus meleagris Pfeiffer, 1853; Bulimus monachus Pfeiffer, 1857; Bulimus montagnei d’Orbigny, 1837; Helix montivaga d’Orbigny, 1835; Bulimus muliebris Reeve, 1849; Bulimus nigrofasciatus Pfeiffer in Philippi 1846; Bulimus nitelinus Reeve, 1849; Helix oreades d’Orbigny, 1835; Helix polymorpha d’Orbigny, 1835; Bulimus praetextus Reeve, 1849; Bulinus proteus Broderip, 1832; Bulimus rusticellus Morelet, 1860; Helix sporadica d’Orbigny, 1835; Bulimus sulphureus Pfeiffer, 1857; Helix thamnoica var. marmorata d’Orbigny, 1835; Bulinus translucens Broderip in Broderip and Sowerby I 1832; Helix trichoda d’Orbigny, 1835; Bulinus ustulatus Sowerby I, 1833; Bulimus voithianus Pfeiffer, 1847; Bulimus yungasensis d’Orbigny, 1837.The type status of the following taxa is changed to lectotype in accordance with Art. 74.6 ICZN: Bulimulus (Drymaeus) caucaensis da Costa, 1898; Drymaeus exoticus da Costa, 1901; Bulimulus (Drymaeus) hidalgoi da Costa, 1898; Bulimulus (Drymaeus) interruptus Preston, 1909; Bulimulus (Drymaeus) inusitatus Fulton, 1900; Bulimulus latecolumellaris Preston, 1909; Bulimus (Otostomus) napo Angas, 1878; Drymaeus notabilis da Costa, 1906; Drymaeus notatus da Costa, 1906; Bulimulus (Drymaeus) nubilus Preston, 1903; Drymaeus obliquistriatus da Costa, 1901; Bulimus (Drymaeus) ochrocheilus E.A. Smith, 1877; Bulimus (Drymaeus) orthostoma E.A. Smith, 1877; Drymaeus expansus perenensis da Costa, 1901; Bulimulus pergracilis Rolle, 1904; Bulimulus (Drymaeus) plicatoliratus da Costa, 1898; Drymaeus prestoni da Costa, 1906; Drymaeus punctatus da Costa, 1907; Bulimus (Leptomerus) sanctaeluciae E.A. Smith, 1889; Bulimulus (Drymaeus) selli Preston, 1909; Drymaeus subventricosus da Costa, 1901; Bulimulus (Drymaeus) tigrinus da Costa, 1898; Drymaeus volsus Fulton, 1907; Drymaeus wintlei Finch, 1929; Bulimus zhorquinensis Angas, 1879; Bulimulus (Drymaeus) ziczac da Costa, 1898.The following junior subjective synonyms are established: Bulimus antioquensis Pfeiffer, 1855 = Bulimus baranguillanus Pfeiffer, 1853; Drymaeus bellus da Costa, 1906 = Drymaeus blandi Pilsbry, 1897; Bulimus hachensis Reeve 1850 = Bulimus gruneri Pfeiffer, 1846 = Bulimus columbianus Lea, 1838; Bulimus (Otostomus) lamas Higgins 1868 = Bulimus trujillensis Philippi, 1867; Bulimulus (Drymaeus) binominis lascellianus E.A. Smith, 1895 = Bulimulus (Drymaeus) binominis E.A. Smith, 1895; Drymaeus multispira da Costa, 1904 = Helix torallyi d’Orbigny, 1835; Bulimulus (Drymaeus) plicatoliratus Da Costa, 1898 = Bulimus convexus Pfeiffer, 1855; Bulimus sugillatus Pfeiffer, 1857 = Bulimus rivasii d’Orbigny, 1837; Bulimus meridionalis Reeve 1848 [June] = Bulimus voithianus Pfeiffer, 1847.New combinations are: Bostryx montagnei (d’Orbigny, 1837); Bostryx obliquiportus (da Costa, 1901); Bulimulus heloicus (d’Orbigny, 1835); Drymaeus (Drymaeus) lusorius (Pfeiffer, 1855); Drymaeus (Drymaeus) trigonostomus (Jonas, 1844); Drymaeus (Drymaeus) wintlei Finch, 1929; Drymaeus (Mesembrinus) conicus da Costa, 1907; Kuschelenia (Kuschelenia) culminea culminea (d’Orbigny, 1835); Kuschelenia (Kuschelenia) culmineus edwardsi (Morelet, 1863); Kuschelenia (K.) gayi (Pfeiffer, 1857); Kuschelenia (Kuschelenia) tupacii (d’Orbigny, 1835); Kuschelenia (Vermiculatus) anthisanensis (Pfeiffer, 1853); Kuschelenia (Vermiculatus) aquilus (Reeve, 1848); Kuschelenia (Vermiculatus) bicolor (Sowerby I, 1835); Kuschelenia (Vermiculatus) caliginosus (Reeve, 1849); Kuschelenia (Vermiculatus) cotopaxiensis (Pfeiffer, 1853); Kuschelenia (Vermiculatus) filaris (Pfeiffer, 1853); Kuschelenia (Vermiculatus) ochracea (Morelet, 1863); Kuschelenia (Vermiculatus) petiti (Pfeiffer, 1846); Kuschelenia (Vermiculatus) purpuratus (Reeve, 1849); Kuschelenia (Vermiculatus) quechuarum (Crawford, 1939); Naesiotus cinereus (Reeve, 1849); Naesiotus dentritis (Morelet, 1863); Naesiotus fontainii (d’Orbigny, 1838); Naesiotus orbignyi (Pfeiffer, 1846); Protoglyptus pilosus (Guppy, 1871); Protoglyptus sanctaeluciae (E.A. Smith, 1889).Type material of the following taxa is figured herein for the first time: Bulimus cinereus Reeve, 1849; Bulimus coriaceus Pfeiffer, 1857; Bulimulus laxostylus Rolle, 1904; Bulimus pliculatus Pfeiffer, 1857; Bulimus simpliculus Pfeiffer, 1855.     

Anatomical Description of Anctus angiostomus (Wagner, 1827) from Northeastern Bahia,Brazil (Gastropoda,Pulmonata, Bulimulidae)

Anctus angiostomus (Wagner, 1827) is herein described anatomically, based on material collected at Queimadas, BA, caatinga habitat. This species is characterized by closed primary and secondary ureters; salivary glands distant from the buccal bulb; a poorly developed stomac h; a characteristic mode of emergence of the gonad duct from the annexe glandular sac; very long spermoviduct; a short oviduct and vagina; very long and slender penis and epiphallus and a long flagellum with retractor muscle in the tip.     

Polymorphic microsatellite DNA markers in the endangered land snail,Trichia caelata (Gastropoda,Stylommatophora)

Eight novel polymorphic microsatellite loci are presented for the endangered land snail Trichia caelata, a rare species endemic to the Northwestern Jura mountains, Switzerland. The number of alleles per locus ranged from six to 17. At seven loci, the expected heterozygosity differed significantly from observed heterozygosity. No evidence for linkage disequilibrium was detected between locus pairs. We are currently using these markers to investigate the genetic population structure of T. caelata in its restricted distribution area.     

Blasenzellen im Bindegewebe des Schlundrings von Cepaea nemoralis L. (Gastropoda,Stylommatophora)

Zusammenfassung Die Blasenzellen stellen ein typisches Zellelement im Bindegewebe der Gastropoden dar. Licht- und elektronenmikroskopische Untersuchungen an Cepaea nemoralis haben gezeigt, daß der größte Teil einer Blasenzelle mit einer veränderlichen Glykogenmenge angefüllt ist. Diese zentrale Glykogenansammlung verdrängt das Zytoplasma mit seinen Organellen auf den peripheren Bereich der Zelle einschließlich der Zellausläufer und einen schmalen Saum um den Zellkern. Das wichtigste Identifizierungs-merkmal der Blasenzelle ist eine sehr spezialisierte — hier als Spaltenapparat bezeichnete — Oberflächendifferenzierung. Die Auswertung von Serienschnitten hat gezeigt, daß diese Oberflächenstruktur durch eine zum Teil verzweigte Invagination des extrazellulären Raumes gebildet wird, die wiederum von der Blasenzelle durch eine mäanderförmig unterbrochene Platte abgedeckt ist. Zwischen dem Spaltenapparat der Blasenzellen und dem Reusenapparat der Podozyten der Niere scheint eine Ähnlichkeit zu bestehen.

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Globular cells of the ganglionic connective tissue sheath of Cepaea nemoralis L. (Gastropoda, Stylommatophora)I. The ultrastructure of the cells

Summary The globular cells are typical elements of the connective tissue of Gastropods. Light- and electronmicroscopic investigations of Cepaea nemoralis have shown, that these cells are filled with variable contents of glycogen, accumulated in the centre of the cell. This crowds the cytoplasm and the cell organelles into the peripheral area, including the cell processes and a narrow band surrounding the nucleus. The typical element of the globular cell is a special differentiation of the cell surface, the so-called Spaltenapparat. The three-dimensional organisation of the Spaltenapparat has been analysed by serial ultrathin sections. The reconstruction shows, that the Spaltenapparat consists of numerous branched invaginations of the extracellular space covered by very small, winding cell processes; there are tiny clefts between them. There appears to be some similarity between the Spaltenapparat of the globular cells and the pedicels of the podocytes of the renal glomerulus.

Frau Prof. Dr. A. Nolte danke ich für anregende Diskussion, Frau R. Dingerdissen und Herrn Dr. Kappert für technische Hilfe.     

Blasenzellen im Bindegewebe des Schlundrings von Cepaea nemoralis L. (Gastropoda,Stylommatophora)

Zusammenfassung Experimentelle Untersuchungen am Schlundringbindegewebe von Cepaea nemoralis haben ergeben, daß — abgesehen von einigen Blutzellen—allein die Blasenzellen befähigt sind, injiziertes Ferritin aufzunehmen. Diese Substanz gelangt aus der Hämolymphe der Körperhöhle über das Gefäßsystem durch das Endothel der Kapillaren in die interzellulären Räume des Bindegewebes und von dort ausschließlich zu den Blasenzellen. Elektronenmikroskopisch zeigt sich, daß die Blasenzellen das Ferritin wahrscheinlich nur durch Endozytose im Bereich des Spaltenapparates aufnehmen. Das Ferritin wird nicht von der Zelle abgebaut, sondern auf engstem Raum, zum Teil in parakristalliner Anordnung, in Endosomen gespeichert.Die Fähigkeit der Blasenzellen, Fremdstoffe selektiv aufzunehmen, läßt vermuten, daß sie eine analoge Bedeutung für die Gastropoden haben wie die Pericardialzellen für Insekten oder das Retikuloendotheliale System für die Vertebraten.

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Globular cells of the ganglionic connective tissue sheath of Cepaea nemoralis L. (gastropoda, stylommatophora)

Summary Experimental investigations of the ganglionic connective tissue sheath of Cepaea nemoralis have shown, that — except for some blood cells — only the globular cells are capable for the uptake of injected Ferritin. This substance gets out of the hemolymph of the body cavity through the blood-vessels and capillaries, across the collagenous connective tissue into the cytoplasm of the globular cells. The globular cells take up the Ferritin by endocytosis, exclusively by the invagination of the Spaltenapparat. The Ferritin remaines accumulated in endosomes sometimes having a paracrystalline pattern. Because of their capability to incorporate and accumulate injected substances, the globular cells have been compared with the pericardial cells of insects respectively with the reticuloendothelial system of vertebrates.

Frau Prof. Dr. Angela Nolte danke ich für anregende Diskussion, Frau Dingerdissen und Herrn Kappert für technische Hilfe.     

Light and electron microscopy study of the salivary gland secretory cells of Helicoidea (Gastropoda, Stylommatophora)

We have studied the secretory goblet-cells of the salivary gland of six species of Helicoidea: Elona quimperiana, Trissexodon constrictus, Hygromia limbata, Cernuella aginnica, Cepaea nemoralis and Helix aspersa, using light microscopy and transmission electron microscopy. In each of the species studied, we have been able to demonstrate the presence of four cell types. Following a comparative study with the goblet-gland cells present in the six species in question, and the comparison of our data with previously published reports on the entire set of Stylommatophora, we have established the homologies corresponding to the cell types observed. Our hypotheses were based primarily on the morphology of the rough endoplasmic reticulum and of the secretory vesicles. Accordingly, we have defined five cell types for these six species. The first three cell types, A, B and C, appear in the six species studied and seem to be present in all the stylommatophores. In order to standardize the terminology used by the different authors, we propose that these cell types be called: 'swollen RER cisterns mucocyte', 'granular mucocyte' and 'alveolar cell', respectively. The D-cell type or 'basophilous cell' is present only in Hygromia limbata, Cernuella aginnica, Cepaea nemoralis and Helix aspersa. The E-cell type or 'vacuolated cell' appears only in Elona quimperiana and Trissexodon constrictus.     

Redescription of Potamolithus paranensis (Pilsbry, 1911) and Potamolithus simplex (Pilsbry, 1911) (Gastropoda: Tateidae)

Potamolithus Pilsbry &; Rush, 1896 is a species-rich genus, endemic to South America, with many of its species considered Vulnerable due to a restricted distribution; half of them are called into question, since they are known only from their shells. The purpose of this article is to describe the anatomy of P. paranensis (Pilsbry, 1911 Pilsbry, H.A. (1911) Non-marine Mollusca of Patagonia. In: Scott, W.B. (Ed.), Reports of the Princeton University Expeditions to Patagonia, 1896–1899, Vol 3, Zoology, Part V. The University, USA, Princeton, NJ, pp. 513–633. [Google Scholar]) and P. simplex (Pilsbry, 1911 Pilsbry, H.A. (1911) Non-marine Mollusca of Patagonia. In: Scott, W.B. (Ed.), Reports of the Princeton University Expeditions to Patagonia, 1896–1899, Vol 3, Zoology, Part V. The University, USA, Princeton, NJ, pp. 513–633. [Google Scholar]) from the Argentinean Misiones province, and to evaluate the value of anatomical features in this genus. These two species differ in penis morphology and pigmentation, ctenidium length, and relative position of the opening of the pallial oviduct, seminal receptacle and bursa copulatrix. Consequently, it appears that anatomical data could help solve taxonomic conflicts that are currently unresolved by shell morphology alone.     

四川西北部巴蜗牛类研究兼一新种描述(腹足纲:肺螺亚纲:柄眼目)

对川西北陆生贝类巴蜗牛科进行了系统整理.其中对假弯巴蜗牛[Bradybaena (Bradybaena) pseudocampylaea (Moellendorff)]、松山巴蜗牛[Bradybaena (Bradybaena) sueshanensis Pilsbry]、单带反向巴蜗牛[Bradybaena (Bradybaena) controversa monotaeniata Pilsbry]进行了解剖.描述了新种茂县蛇蜗牛Pseudiberus (Pseudiberus) maoensis sp.nov.,其模式标本及其他研究标本均保存于中国科学院动物研究所.     

The status of the genus Bostryx Troschel, 1847, with description of a new subfamily (Mollusca, Gastropoda, Bulimulidae)

The status of the genus Bostryx is discussed and, based on morphological and molecular data, restricted to a group of species related to Bostryx solutus, for which the new subfamily name Bostrycinae is introduced.     

Vergleichende Untersuchungen an Amoebozyten und Blasenzellen von Cepaea nemoralis L. (Gastropoda,Stylommatophora)

Summary The pecten oculi of the sparrow consists of capillaries, pigment cells and a superficial membrane. Because of the loose structure of the first two components broad intercellular spaces occur in the pecten. The capillary wall consists of endothelial cells and a perivascular membrane. The bodies of the endothelial cells are flattened, while the plasmalemma of both their surfaces (basal and luminal) is strongly folded and forms numerous microfolds with an average thickness of 700 Å. The height of the inner microfolds is 1.4–1.8 m, the outer microfolds measure 1.3–1.6 m. They lie densely packed side by side and are separated by recesses of the capillary lumen ca. 500 Å wide. Due to this the surface of the endothelial cell is increased by approximately 20-fold. The adjoining endothelial cells abut or overlap with margins, and are joined by the zonulae adherentes. Pigment cells form numerous processes and microvilli. Some rest on the capillary walls, while others penetrate the superficial membrane of the pecten or fill the intercellular spaces.     

Biogeography of the Limacoidea sensu lato (Gastropoda: Stylommatophora): vicariance events and long-distance dispersal

Aim Reconstruction of the historical biogeography of the Limacoidea sensu lato (including the Staffordiidae, Dyakiidae, Gastrodontoidea, Parmacelloidea, Zonitidae, Helicarionoidea and Limacoidea). Evaluation of the relative importance of dispersal and its consequences. Location World‐wide. Methods Weighted ancestral area analysis. Results The ancestral areas of the individual clades have been delimited using weighted ancestral area analysis and a sequence of possible vicariance and dispersal events has been suggested. The results of the ancestral area analysis have tentatively been correlated with Cretaceous and Tertiary palaeogeography. The widely overlapping distribution patterns of several families of the Limacoidea testify to extensive dispersal events. Dispersal capacity of land snails is correlated with body size. The significant negative correlation between body size and distribution area size corroborates the importance of passive dispersal for the evolution of the distribution patterns. Main conclusions The existence of extensive dispersal events of poor active dispersers like land snails diminishes the importance of recent distribution patterns for the reconstruction of palaeogeography. On the other hand, dispersal ensures that biogeographical data reflect the geographical configurations at a given time and renders the use of palaeobiogeographic data for the reconstruction of palaeogeographic configurations of the respective age possible.