Desarrollo morfológico e histológico del sistema reproductor de Pomacea patula catemacensis (Baker 1922 (Mollusca, Caenogastropoda: Ampullariidae Morphological and histological development of the reproductive system of Pomacea patula catemacensis (Baker 1922 (Mollusca, Caenogastropoda: Ampullariidae
Full Text Available El "tegogolo" Pomacea patula catemacensis es un gasterópodo dulceacuícola comestible, endémico del Lago de Catemaco en Veracruz, México. En los últimos años las poblaciones naturales se han visto diezmadas debido a que su captura se realiza sin control, a lo que se suma el alto grado de deterioro ambiental que presenta el lago, producto del "azolvamiento", así como por la contaminación por plaguicidas y detergentes. El objetivo del presente estudio fue caracterizar histológica y morfológicamente el sistema reproductor de P. patula catemacensis y determinar las etapas de madurez gonádica en condiciones de laboratorio. Se determinó que la maduración depende de la talla y no de la edad de los organismos, y se identificaron cuatro etapas principales en el desarrollo de machos y hembras: Los estadios y sus longitudes promedio ± intervalo de confianza del 95 % son (1 inmadura o indiferenciada (talla de 0,72 a 7 mm, (2 maduración temprana (18,95 ± 1,96 mm, (3 maduración intermedia (29,29 ± 4,9 mm y (4 madurez total (35,89 ± 3,92 mm. En este molusco los sexos están separados, la fertilización es interna y el desarrollo es ovovivíparo. En las hembras la secreción de albúmina y de carbonato de calcio se realiza en la glándula de la albúmina, característica en la que difiere de otras especies como P. paludosa y P. canaliculata, las cuales poseen además glándula de la cápsula. Es posible identificar el grado de madurez de los caracoles utilizando criterios anatómicos visuales, como la glándula de la albúmina, en el caso de la hembra, y el órgano copulador en el machoThe "apple snail" Pomacea patula catemacensis is an edible freshwater mollusc, endemic to the Catemaco Lake in Veracruz, Mexico. During the past few years, the natural populations of this species have been depleted mainly by uncontrolled fishery, and because of environmental degradation and pollution by pesticides and detergents. In the present study, we carried
Damborenea, C; Brusa, E; Paola, A
Pomacea canaliculata is a common gastropod in freshwater habitats from Central and Northern Argentina, extending northwards into the Amazon basin. Several Platyhelminthes have been reported associated to P. canaliculata, sharing an intimate relationship with this gastropod host. The objectives of this study were to describe the symbiotic species assemblages associated to P. canaliculata in the study area, and to disclose differences among them. Samples were taken in three typical small streams and one artificial lentic lagoon, all connected with the Rio de la Plata estuary. The 81.53% were infested with different symbiotic (sensu lato) species. Among the Platyhelminthes, the commensal Temnocephala iheringi Haswell, 1893 was highly prevalent in all samples, always in the mantle cavity. Four trematode taxa were recognized: (a) metacercariae of Echinostoma parcespinosum Lutz, 1924 in the mantle cavity and sporocysts in the digestive gland; (b) metacercariae of Dietziella egregia (Dietz, 1909) in the pericardial cavity; (c) unidentified xiphidiocercariae and (d) unidentified sporocysts and furcocercariae in the digestive gland. Nematode larvae and oligochaetes were found in two localities in the mantle cavity. Among the Annelida, Helobdella ampullariae Ringuelet, 1945 was found in the mantle cavity and lung of snails only from one locality. Our results show that although some of the symbionts are present in all localities, others are restricted to some particular ones, whether in their absolute numbers or in their relative abundance. Thus, each hosting population at the studied localities may be defined by the particular combination of symbionts that bears. PMID:17375466
Henningsen, Justin P.; Lance, Stacey L.; Jones, Kenneth L.; Hagen, Chris; Laurila, Joshua; Cole, Rebecca A.; Perez, Kathryn E.
Bithynia tentaculata (Linnaeus, 1758), a snail native to Europe, was introduced into the US Great Lakes in the 1870's and has spread to rivers throughout the Northeastern US and Upper Mississippi River (UMR). Trematode parasites, for which B. tentaculata is a host, have also been introduced and are causing widespread waterfowl mortality in the UMR. Waterfowl mortality is caused by ingestion of trematode-infected B. tentaculata or insects infected with parasites released from the snails. We isolated and characterized 17 microsatellite loci from the invasive faucet snail, B. tentaculata (Gastropoda: Caenogastropoda: Bithyniidae). Loci were screened in 24 individuals of B. tentaculata. The number of alleles per locus ranged from 2 to 6, observed heterozygosity ranged from 0.050 to 0.783, and the probability of identity values ranged from 0.10 to 0.91. These new loci provide tools for examining the origin and spread of invasive populations in the US and management activities to prevent waterfowl mortality.
Full Text Available For over 40 years malacologists have been discussing the taxonomical status of Heleobia species, an enigmatic genus from Cochliopidae family (Caenogastropoda: Rissooidea. As with other rissooidean families, the considerable character convergence and the paucity of anatomical synapomorphies has proved to be a problem in resolving cochliopid phylogenetic relations and establishing the validity of several nominal cochliopid species. Here we present a molecular contribution to solve the taxonomical status of one of the most abundant Southern South America cochliopid genera which has many endemic species. We report molecular evidence that supports three of the four Heleobia groups described for this region, the "australis", "parchappii" and "piscium" groups. The fourth, the "hatcheri" group, belongs not to Heleobia but to a different genus which itself should not be considered as part of the family Cochliopidae but closely related to genus Potamolithus Pilsbry & Rush, 1896.
Silvana Carvalho Thiengo
Full Text Available A description of Pomacea sordida (Swainson, 1823 collected in Caxias and Nova Iguaçu, state of Rio de Janeiro, is presented. The shell is globose, heavy, whith greenish or horn-colored periostracum and dark spinal bands; apex subelevated, 4-5 moderately shoudered whorls, increasing rather rapidly and separated by deep suture. Aperture large, moderately round, yellowish or violaceous; lip thick and sometimes dark brown; umbilicus large and deep; operculum corneous and heavy, entirely closing the aperture. Ratios: shell width/shell length = 0.81-0.91 (mean 0.86; aperture length/shell length = 0.66-0.75 (mean 0.70. Testis, spermiduct and penis pouch as in Pomacea lineata (Spix, 1827. Seminal vesicle whitish and bean-shaped. Prostate cylindric and narrow, cream in coloar as the testis. Penis whiplike whith a closed circular spermiduct. Penial sheath elongated and tapered, with its distal tip turned to the right; outer basal gland situated on the left; inner median gland rounded; apical gland elongated and wrinkled. Ovary composed of branched whitish tubules lying superficially on the digestive gland; oviduct and seminal receptacle as in P. lineata; albumen gland yellowish - orange. Vestigial male copulatory apparatus (penis and its sheath present in all females examined.Nesse trabalho é apresentada a descrição de Pomacea sordida (Swainson, 1823, coletada em Caxias e Nova Iguaçu, Estado do Rio de Janeiro. Concha globosa, espessa, com perióstraco esverdeado ou castanho e com faixas espirais escuras; ápice pouco elevado, 4-5 giros moderadamente arredondados, crescendo relativamente rápido, separados por suturas profundas. Abertura grande, moderadamente arredondada, amarelada ou violácea; lábio espesso e algumas vezes marrom escuro; umbílico grande e profundo; opérculo córneo e espesso, fechando completamente a abertura. Razões: largura da concha/comprimento da concha=0.81-0.91 (média 0.86; comprimento da abertura/comprimento da concha=0.66-0.75 (média 0.70. Testículo, espermiduto e bolsa do pênis como em Pomacea lineata (Spix, 1827. Vesícula seminal esbranquiçada e em forma de feijão. Próstata cilíndrica e estreita, de cor creme como o testículo. Pênis em forma de chicote, com espermiduto circular e fechado. Bainha do pênis alongada tendo sua largura diminuída da base para a extremidade, sendo esta última voltada para a direita; glândula basal extrema situada à esquerda; glândula mediana interna arredondada; glândula apical alongada e com sulcos. Ovário composto de túbulos brancos ramificados dispostos superficialmente sobre a glândula digestiva verde. Oviduto e receptáculo seminal como em P. lineata; glândula de albume de cor alaranjada; ovos prismáticos e calcáreos de cor alaranjada. Aparelho copulador masculino vestigial (pênis e sua bainha presente em todas as fêmeas examinadas.
Full Text Available A total of nineteen continental native mollusc species are confirmed for the Santa Catarina State (SC(organized in ten Genera and seven Families, one aquatic Prosobranchia/Caenogastropoda (Ampullariidae,six Pulmonata terrestrial gastropods (one Ellobiidae, three Megalobulimidae and two micro-snails –Charopidae and Streptaxidae and twelve freshwater mussels (eight Mycetopodidae and four Hyriidae. Thesespecies are designated by the International Union for Conservation of the Nature – IUCN as follows: seven as"Vulnerable", six "In Danger" and six “Without Category Established”. The general regional threats that thesespecies are subjected to are briefly analyzed.
Silvana C. Thiengo
Full Text Available This paper deals with the morphology of Pomacea caniculata (Lamarck, 1822 collected at Corrientes, Argentina. Comparison is made with Pomacea lineata (Spix, 1827 and Pomacea sordida (Swainson, 1823. The shell is globose, heavy, with greenish or horn-colored periostracum and dark spiral bands; apex subelevated, 5-6 whorls increasing rather rapidly and separated by very deep suture. Aperture large, rounded to subelongated; lip sometimes reddish; umbilicus large and deep; operculum corneous, entirely closing the aperture. Ratios: shell width/shell length = 0.78-0.96 (mean 0.86; aperture length/shell length = 0.68-0.77 (mean 0.72. Radula similar to other congeneric species. Testis and spermiduct as in P. lineata and P. sordida; prostate cylindric and short, cream in color as the testis. Penial sheath straight bearing a central outer gland deeply embedded in the tissue of its basal portion and a large wrinkled gland occupying 2/3 of the distal tip of its inner surface; the rigth margin of the sheath overlaps the left one until 2/3 of its proximal end. Female reproductive apparatus similar to that P. lineata; vestigial male copulatory apparatus (penis and its sheath present in all females examined.
Silvana C. Thiengo; Carlos E. Borda; J. L. Barros Araújo
This paper deals with the morphology of Pomacea caniculata (Lamarck, 1822) collected at Corrientes, Argentina. Comparison is made with Pomacea lineata (Spix, 1827) and Pomacea sordida (Swainson, 1823). The shell is globose, heavy, with greenish or horn-colored periostracum and dark spiral bands; apex subelevated, 5-6 whorls increasing rather rapidly and separated by very deep suture. Aperture large, rounded to subelongated; lip sometimes reddish; umbilicus large and deep; operculum corneous, ...
YANG Jingwen; ZHANG Suping
The family Nassariidae includes a number of species that are distributed throughout the world.Each species has a characteristic shell shape,tooth shape,and behavior.However,the classification of species in this family of the Rhachiglossa is controversial.We describe the radulae of 22 species from China in detail using optical and scanning electron microscopy.These species are considered to be representatives of two subfamilies,two genera,and 10 subgenera.Our results suggest that the morphology of the central tooth and the pair of lateral teeth and the presence or absence of a pair of intermediate accessory lateral teeth could be used to distinguish among species.We found no support for the subgeneric differentiation of the species.However,the presence or absence of the intermediate lateral accessory plate was characteristic of species divisions.We noted sexual dimorphism in the shape of the teeth in some species,and considerable variability of the shape of teeth within a single species.Based on our results,the genus Nassarius cannot be split into subgenera using radula morphology.
Carlos Paredes; Franz Cardoso
En el presente trabajo se realiza una revisión taxonómica de la familia Calyptraeidae Lamarck, 1809, en la costa Peruana. Se confirma la presencia de 17 especies de las 19 reportadas por diversos autores. Crepidula arenata (Broderip, 1834) es sinónimo de C. excavata (Broderip, 1834). Se da información sobre la distribución geográfica y algunas relaciones ecológicas.
Ana R. A. Coelho; Gonçalo J. P. Calado; Maria T. Dinis
Investigations on the reproductive biology, life cycle and feeding habits of Pomacea bridgesiihave been undertaken to assess its potential as a cultured species for the ornamental trade. The speciesis dioecious and, under optimal culture conditions of temperature and food supply, it can breed all yearround. The total developmental period at 23±1ºC varied from 15 to 24 days after oviposition. Hatchingcan last for up to 20 hours in the same egg cluster. Hatching success was very high (mean94.56...
Ana R. A. Coelho
Full Text Available Investigations on the reproductive biology, life cycle and feeding habits of Pomacea bridgesiihave been undertaken to assess its potential as a cultured species for the ornamental trade. The speciesis dioecious and, under optimal culture conditions of temperature and food supply, it can breed all yearround. The total developmental period at 23±1ºC varied from 15 to 24 days after oviposition. Hatchingcan last for up to 20 hours in the same egg cluster. Hatching success was very high (mean94.56±0.62% and no significant differences were observed in hatching rates between different clutchsizes. Development is direct and juveniles hatch at shell length (SL = 2.4±0.25 mm. Maturity is reached192±1.5 days after hatching and at SL = 32.80±2.03 mm. Two feeding experiments were undertaken toassess the impact of food type on juvenile survival during the first 8 days post-hatching and subsequentgrowth until 90 days post-hatching. Compatibility between other fish and plants fresh-water aquariumspecies were performed. A combination of environmental tolerance, moderately amphibious behavior,fast growth, short development and hatching at an advanced stage, compatibility with other aquariumspecies (fishes or other invertebrates, and simple low cost diet, make P. bridgesii highly suitable forintensive culture for the ornamental trade.
A new species of Temnocephala (Platyhelminthes, Temnocephalida commensal of Pomella megastoma (Mollusca, Ampullariidae from Misiones, Argentina Una especie nueva de Temnocephala (Platyhelminthes, Temnocephalida comensal de Pomella megastoma (Mollusca, Ampullariidae de Misiones, Argentina
Full Text Available Temnocephala lamothei n. sp., a commensal of Pomella megastoma (Sowerby, 1825, is described herein from specimens collected at Arroyo Yabotí-Miní (Misiones province, Argentina. Juveniles and adults were removed from the mantle cavity by host relaxation. Distinctive characters of the new species are: non-partitioned intestine; conical cirrus with 1 face flat and another concave; distal area with spines, as evidenced by a strong, oblique sclerotized ring, and 2 rows of long spines, an internal one with long spines arising from base of introvert and an external one arising from distal end of the introvert. The closest species are T. iheringi, T. rochensis and T. haswelli, which are also commensals of mollusc species. The presence of this new species of Temnocephala, and its similarity to the other species that are commensals of molluscan species, suggest the existence of a morphologically homogeneous group.Temnocephala lamothei n. sp., comensal de Pomella megastoma (Sowerby, 1825, se describe para el arroyo Yabotí-Miní, provincia de Misiones, Argentina. Se extrajeron ejemplares juveniles y adultos de la cavidad paleal, por relajación de los hospederos. Las características distintivas de la nueva especie son: intestino no septado, cirro de forma cónica, con una cara plana y otra cóncava, zona distal con espinas evidente por un fuerte anillo oblicuo esclerosado. Dos hileras de espinas se reconocen en el extremo distal, 1 interna de espinas largas, que surge desde la base del introverso, y 1 externa, que surge del extremo distal del mismo. Las especies más semejantes son T. iheringi, T. rochensis y T. haswelli, especies comensales de moluscos con las que es comparada. El hallazgo de esta nueva especie de Temnocephala y sus características semejantes a las restantes especies del género comensales de moluscos, sugieren que las especies conocidas hasta la fecha formen un grupo morfológicamente homogéneo.
Demian, E S; Yousif, F
The nervous system is ectodermal in origin. All nerve ganglia arise separately by proliferation and later delamination from the ectoderm, not by invagination. They become secondarily connected to one another by commissures and connectives developing as extensions from the peripheral layer of ganglionic nerve cells. Rudiments of the cerebral, pedal, pleural and intestinal (parietal) ganglia arise almost simultaneously at a relatively early stage (Stage V). The cerebral ganglia develop from the ectoderm of the head plates. Rudiments of the pedal and pleural ganglia are separate at their inception. They later fuse (Stage VI) to form a pleuro-pedal ganglionic mass on each side. The 2 intestinal ganglia are symmetrical at the beginning, but they soon lose their symmetry as a result of torsion. The right ganglion crosses to the left over the gut and persists as the supraintestinal ganglion. The left or subintestinal ganglion shifts to the right and forward, and fuses with the right pleural ganglion (Stage VIII), thus obscuring the chiastoneury. The paired buccal and single visceral (abdominal) ganglia start differentiating in Stage VII. The former develop from the ectodermal wall of the stomodaeum, while the visceral ganglion delaminates from the right wall of the visceral sac, then shifts to the left during torsion. The statocysts develop early (Stage V) from 2 ectodermal invaginations on either side of the rudimentary foot. They later separate from the overlying ectoderm and statoconi appear in their lumina. Contrary to earlier reports on related ampullariids, the osphradium proved to be ontogenetically older than the mantle and mantle cavity. It starts differentiating as a thickened ectodermal plate in the right wall of the visceral sac (Stage V). During torsion, it becomes engulfed in the mantle cavity and shifts to the left side, then is carried forward as the mantlegrow. The eyes develop late (Stage IX) as ectodermal invaginations which rapidly separate from the ectoderm to form closed vesicles. Their cells start differentiating before hatching to form the retina, in which pigment is deposited, and the inner cornea. The lens is secreted in the lumen of the eye and grows by addition of concentric layers of secretion. PMID:1221226
Collado, Gonzalo A
In the family Cochliopidae, Heleobia Stimpson, 1865 is the most speciose genus in South America, with about 90 species (Hershler & Thompson 1992; Cazzaniga 2011). A recent molecular and morphological analysis performed in northern Chile (Atacama Desert) showed that the previously undescribed springsnails from Aguada de Chorrillos belong to Heleobia (Collado et al. 2013). In this study I formally describe this new species. Although this paper does not treat morphology in detail, the anatomical characters, in combination with the previously published molecular data provides a strong basis for recognizing this population as a distinct species. PMID:25781755
Full Text Available The minute (adult size 1.3–4.8 mm land snail species of the family Diplommatinidae in the Fiji archipelago are revised based on historical material and modern (1998–99 collections targeting limestone outcrops on the largest island, Viti Levu, and several smaller islands in the Lau group. The forty-two species (including 30 new species belong to the genera Moussonia Semper, 1865, Palaina Semper, 1865 and Diancta Martens, 1867, which are briefly characterized and keyed. The diagnostic structure of the inner lamellar system of each species is illustrated. All species except one are endemic to Fiji. In Viti Levu, the 12 localities surveyed each had 1–13 (average 5 species of Diplommatinidae; ten species were each found at a single site only. In the Lau islands, five islands were visited, with 1–4 species per island; four species are known from single islands. The number of historically known species not recollected in 1998–99 (7 species, the number of single-site occurrences (14 species, and the numerous islands — including limestone islands — that have not been surveyed at all, indicate that the 42 species of Diplommatinidae currently known from Fiji represent perhaps only half of the Fiji diplommatinid fauna. Such numbers approach the diplommatinid diversity of Palau (39 described and more than 60 undescribed species, and surpasses by far the diversity of other South Pacific archipelagos of comparable land area (New Caledonia, Vanuatu, Samoa. Nomenclatural acts: Lectotypes designated: Diplommatina fuscula, D. fuscula var. vitiana, D. godeffroyana, D. godeffroyana var. latecostata, D. tuberosa, D. martensi var. macrostoma, all Mousson, 1870. Neotypes designated: Diplommatina subregularis, D. ascendens, D. quadrata, all Mousson, 1870. New species: Diancta aurea sp. n., Diancta aurita sp. n., Diancta basiplana sp. n., Diancta controversa sp. n., Diancta densecostulata sp. n., Diancta dextra sp. n., Diancta dilatata sp. n., Diancta distorta sp. n., Diancta pulchella sp. n., Diancta rotunda sp. n., Diancta subquadrata sp. n., Diancta trilamellata sp. n., Moussonia acuta sp. n., Moussonia barkeri sp. n., Moussonia brodieae sp. n., Moussonia longipalatalis sp. n., Moussonia minutissima sp. n., Moussonia obesa sp. n., Moussonia polita sp. n., Moussonia uncinata sp. n., Moussonia vitianoides sp. n., Palaina alberti sp. n., Palaina flammulata sp. n., Palaina glabella sp. n., Palaina kitteli sp. n., Palaina labeosa sp. n., Palaina parietalis sp. n., Palaina sulcata sp. n., Palaina truncata sp. n., Palaina tuberosissima sp. n.
Osikowski, Artur; Georgiev, Dilian; Hofman, Sebastian; Falniowski, Andrzej
Bythinella is a minute dioecious caenogastropod that inhabits springs in central and southern Europe. In the Balkans, previous studies have addressed its morphological and genetic differentiation within Greece and Romania while the Bulgarian species have remained poorly known. The aim of the present paper has been to expand the knowledge on the subject in Bulgaria. Shell morphology and anatomy of the reproductive organs were examined, and a fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene and the nuclear ribosomal Internal Transcribed Spacer 1 (ITS-1) were sequenced from 15 populations. Additional sequences from eight previously studied populations were included in our analyses. Phylogenetic analyses revealed five main mitochondrial DNA clades, which were partly confirmed by analyses of the ITS-1 sequences. The genetic differentiation between the clades was found to be in the range p=2.4-11.8%. Most of the populations belonged to clade I, representing Bythinella hansboetersi, and were distributed in SW Bulgaria. Clades II and III inhabit areas adjacent to clade I and were most closely related with the latter clade. Much more distinct were clade V, found at one locality in NW Bulgaria, and clade IV, found at one locality in SE Bulgaria, close to the sea. Four populations were found in caves, but only one of these represented a distinct clade. Considering the observed pattern of interpopulation differentiation of Bythinella in Bulgaria, we can suppose that isolation between clades I, II and III may have been caused by glaciations during the Pleistocene. The time of isolation between the above three clades and clade IV coincides with the Messinian Salinity Crisis, and the time of isolation between the clade V and the other four most probably reflects the isolation of the Rhodopes from western Balkan Mts by the seawater of the Dacic Basin. PMID:26448701
Hausdorf, Bernhard; Röpstorf, Peter; Riedel, Frank
The phylogenetic relationships and the origin of two groups of rissooid freshwater snails endemic to Lake Baikal were investigated using partial mitochondrial COI, 12S rDNA, and 16S rDNA sequences. The Baikalian Benedictiinae proved to be closely related to the Lithoglyphinae. According to a molecular clock estimate the two groups diverged in the Paleogene. The Benedictiinae might have evolved autochthonously in precursors of Lake Baikal. The Baikalian Baicaliidae are probably most closely related to the Amnicolidae and the Bithyniidae. These groups diverged at the latest during the Cretaceous. Thus the origin of the Baicaliidae predates the origin of the Baikal rift zone. The Baicaliidae evolved probably in other Central Asian freshwater reservoirs. However, the radiation of the extant Baicaliidae only started in the Neogene and might have occurred autochthonously in Lake Baikal. The conchological similarity of the Baicaliidae and the Pyrgulidae is due to convergence. The Pyrgulidae diverged from the common stem lineage of the other hydrobiid families at the latest in the Jurassic. The Bithyniidae is derived from hydrobiids and is related to the Amnicolidae. PMID:12644402
Zabala, S.; Hermida, G. N.; Giménez, J.
The ultrastructure of the euspermatozoa and the paraspermatozoa is investigated in Adelomelon ancilla, through histological section observed by transmission electron microscopy. Euspermatozoa of A. ancilla consists of: (1) a conical acrosomal vesicle (with a short basal invagination, constricted anteriorly) which is flattened at the apex and associated with an axial rod, a centrally perforated basal plate and a short accessory membrane, (2) a rod-shaped, solid and highly electron-dense nucleus (with a short basal fossa containing a centriolar complex and a initial portion of a 9 + 2 axoneme), (3) an elongate midpiece consisting of the axoneme sheathed by 5-6 helical mitochondrial elements each exhibiting a dense U-shaped outer layer, (4) an elongate glycogen piece (where the axoneme is sheathed by nine tracts of glycogen granules), (5) a dense annulus at the junction of the midpiece and glycogen piece, and (6) a short free tail region (where the axoneme is surrounded only by plasma membrane). We observed a parasperm in A. ancilla. This is vermiform in shape and is composed of multiple axonemes and extensive cytoplasm with numerous vesicles, and mitochondria are scattered inside the axonemes. Sperm of A. ancilla is characterized by the euspermatozoa type 2 and the paraspermatozoa morphology belongs to type 5. The U shaped electrodense mitochondrial element in the midpiece of the eusperm and the constriction in the acrosomal vesicle present in A. ancilla are exclusive. We suggest that these characteristics could have taxonomic importance, because these was observed in other volutids and have not been observed in the rest of caenogastropods studies. We consider that the morphology of paraspermatozoa in A. ancilla corresponds to the “lancet” type.
First report of Temnocephala haswelli (Platyhelminthes: Temnocephalida in Pomacea canaliculata (Mollusca: Ampullariidae from Brazil: description update based on specimens from the state of Rio Grande do Sul, Brazil
Samantha A. Seixas
Full Text Available The impact of the discovery of Temnocephala haswelli Ponce de Léon, 1989, described as ectosymbionts of ampullariid apple snails outside of Uruguay, motivated us to collect a large number of specimens of Pomacea canaliculata (Lamarck, 1822 from several localities in the southern portion of the state of Rio Grande do Sul. This species was recorded three times after its description: in a study of chromosomes, in a study about the ultrastructure of the collar receptor cells, and in a study of the Haswell glands, all conducted in Uruguay. A total of 301 specimens of P. canaliculata were collected from 1999 to 2007. Temnocephalans found in the pallial cavity were identified as T. haswelli, which occurred in single infestations or concurrently with Temnocephala iheringi Haswell, 1893. Helminths usually showed a light-orange body pigmentation and conspicuous, intense red-eye pigment. Many taxonomic characters evidenced by several techniques were documented photographically for the first time. The typical curved cirrus, approximately 90°, typical of the species, showed some variation in the width of the shaft base, whereas the first longitudinal row of spines of the introvert appeared with shorter spines. The vagina was found to be thick-walled, but not very muscular, and to have a single, large and slightly asymmetrical sphincter, with the posterior portion of slightly larger diameter. Eggs were observed in the umbilicus and along the suture, but predominantly in the body whorl of the shell. Egg peduncles were found to be very short or, most of the time, the eggs were sessile, always with a long apical filament. The rounded shape of the dorsolateral 'excretory' syncytial epidermal plates had external margins reaching the ventrolateral region of the body and eccentric nephridiopores. This is the first record of the species outside Uruguay and in Brazil.
Full Text Available The Assimineidae are a family of amphibious microgastropods that can be mostly found in estuaries and mangroves in South Africa. These snails often occur in great numbers and are ecologically important to the St Lucia Estuary, which forms a crucial part of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Genetic and shell morphometric analyses were conducted on individuals collected from nine localities distributed from the northern lake regions to the southern lake and the mouth of the St Lucia estuarine lake. Mitochondrial (COI and nuclear (28S DNA was used to construct Bayesian Inference, Neighbour-joining, Maximum Parsimony and Maximum Likelihood trees. Principal Component Analysis and Cluster Analysis were performed on standard shell parameter data. Results indicate that two different taxa are present in St Lucia. The taxon comprising individuals from the South Lake and St Lucia Estuary Mouth is identified as Assiminea cf. capensis Bartsch, in accordance with the latest taxonomic consensus. The taxon comprising assimineid individuals from False Bay, North Lake and South Lake, is here tentatively named “A.” aff. capensis (Sowerby. These two taxa exhibit patterns of spatial overlap that appear to vary depending on environmental parameters, particularly salinity. The need to resolve the complex taxonomy of assimineids is highlighted.
Full Text Available The molluscan shell can be viewed as a petrified representation of the organism’s ontogeny and thus can be used as a record of changes in form during growth. However, little empirical data is available on the actual growth and form of shells, as these are hard to quantify and examine simultaneously. To address these issues, we studied the growth and form of a land snail that has an irregularly coiled and heavily ornamented shell–Plectostoma concinnum. The growth data were collected in a natural growth experiment and the actual form changes of the aperture during shell ontogeny were quantified. We used an ontogeny axis that allows data of growth and form to be analysed simultaneously. Then, we examined the association between the growth and the form during three different whorl growing phases, namely, the regular coiled spire phase, the transitional constriction phase, and the distortedly-coiled tuba phase. In addition, we also explored the association between growth rate and the switching between whorl growing mode and rib growing mode. As a result, we show how the changes in the aperture ontogeny profiles in terms of aperture shape, size and growth trajectory, and the changes in growth rates, are associated with the different shell forms at different parts of the shell ontogeny. These associations suggest plausible constraints that underlie the three different shell ontogeny phases and the two different growth modes. We found that the mechanism behind the irregularly coiled-shell is the rotational changes of the animal’s body and mantle edge with respect to the previously secreted shell. Overall, we propose that future study should focus on the role of the mantle and the columellar muscular system in the determination of shell form.
Delicado, Diana; Machordom, Annie; Ramos, Marian A
Hydrobiidae is one of the largest families of freshwater gastropods comprised of approximately 400 genera and 1000 species. Despite this high level of diversity, most hydrobiid species inhabit fragile ecosystems in restricted distribution areas. In this work, we analyze modes of speciation and causes of diversification in the hydrobiid springsnail subgenus Pseudamnicola (Corrosella). Species of this group typically live in nutrient poor springs and streams and are restricted to mountainous regions of the Iberian Peninsula (Spain) and Southern France. Previous morphological and molecular (based only on the cytochrome c oxidase subunit I (COI) gene) studies revealed 11 nominal Corrosella species. In this study, we enhance published molecular results by generating new data from mitochondrial (16S rRNA and COI) and nuclear ribosomal regions (18S and 28S rRNA) from 50 Corrosella populations. As a result of this study we have identified one new species, making a total of twelve recognized species in the subgenus Corrosella. Our phylogenetic results also reveal the existence of three lineages within the subgenus, and the estimation of time divergence indicates the occurrence of three main speciation events during the upper Miocene to Pleistocene. We test the influence of several geographical and ecological variables and observe that diversification patterns are related to habitat fragmentation rather than environmental conditions. This result suggests that the high level of diversity observed within the subgenus may have resulted from a non-adaptive radiation. The formation of the Iberian Peninsula mountain ranges (the Pyrenees in the north and the Betic Cordillera in the south) and the configuration of the Iberian current hydrographic system played important roles in Corrosella speciation. Additionally, during the Miocene the Iberian Peninsula experienced a gradient of increasing temperature and dryness from north to south, which together with a high level of tectonic activity, may have caused the majority of the diversity found in the southern Iberian Peninsula. PMID:23660110
Liew, Thor-Seng; Vermeulen, Jaap Jan; Marzuki, Mohammad Effendi Bin; Schilthuizen, Menno
Plectostoma is a micro land snail restricted to limestone outcrops in Southeast Asia. Plectostoma was previously classified as a subgenus of Opisthostoma because of the deviation from regular coiling in many species in both taxa. This paper is the first of a two-part revision of the genus Plectostoma, and includes all non-Borneo species. In the present paper, we examined 214 collection samples of 31 species, and obtained 62 references, 290 pictures, and 155 3D-models of 29 Plectostoma species and 51 COI sequences of 19 species. To work with such a variety of taxonomic data, and then to represent it in an integrated, scaleable and accessible manner, we adopted up-to-date cybertaxonomic tools. All the taxonomic information, such as references, classification, species descriptions, specimen images, genetic data, and distribution data, were tagged and linked with cyber tools and web servers (e.g. Lifedesks, Google Earth, and Barcoding of Life Database). We elevated Plectostoma from subgenus to genus level based on morphological, ecological and genetic evidence. We revised the existing 21 Plectostoma species and described 10 new species, namely, P. dindingensis sp. n., P. mengaburensis sp. n., P. whitteni sp. n., P. kayiani sp. n., P. davisoni sp. n., P. relauensis sp. n., P. kubuensis sp. n., P. tohchinyawi sp. n., P. tenggekensis sp. n., and P. ikanensis sp. n. All the synthesised, semantic-tagged, and linked taxonomic information is made freely and publicly available online. PMID:24715783
Thor-Seng Liew; Jaap Jan Vermeulen; Mohammad Effendi Marzuki; Menno Schilthuizen
Abstract Plectostoma is a micro land snail restricted to limestone outcrops in Southeast Asia. Plectostoma was previously classified as a subgenus of Opisthostoma because of the deviation from regular coiling in many species in both taxa. This paper is the first of a two-part revision of the genus Plectostoma, and includes all non-Borneo species. In the present paper, we examined 214 collection samples of 31 species, and obtained 62 references, 290 pictures, and 155 3D-models of 29 Plectostom...
Full Text Available We describe three new species of springsnails (genus Pyrgulopsis from the Amargosa River basin, California and Nevada (P. licina sp. n., P. perforata sp. n., P. sanchezi sp. n., each of which was previously considered to be part of P. micrococcus. We also restrict P. micrococcus to its type locality area (Oasis Valley and redefine a regional congener, P. turbatrix, to include populations from the central Death Valley region and San Bernardino Mountains that had been previously identified as P. micrococcus. The five species treated herein form genetically distinct lineages that differ from each other by 4.2–12.6% for mtCOI and 5.2–13.6% for mtNDI (based on previously published and newly obtained data, and are diagnosable by shell and/or penial characters. The new molecular data presented herein confirm sympatry of P. licina and P. sanchezi in Ash Meadows (consistent with morphological evidence and delineate an additional lineage of P. micrococcus (in the broad sense that we do not treat taxonomically owing to the paucity of morphological material. Conservation measures are needed to ensure the long term persistence of populations of P. micrococcus and a genetically differentiated lineage of P. sanchezi which live in disturbed habitats on private lands.
Robert Hershler; Hsiu-Ping Liu; Corbin Bradford
We describe three new species of springsnails (genus Pyrgulopsis) from the Amargosa River basin, California and Nevada (P. licina sp. n., P. perforata sp. n., P. sanchezi sp. n.), each of which was previously considered to be part of P. micrococcus. We also restrict P. micrococcus to its type locality area (Oasis Valley) and redefine a regional congener, P. turbatrix, to include populations from the central Death Valley region and San Bernardino Mountains that had been previously identified a...
Full Text Available Plectostoma is a micro land snail restricted to limestone outcrops in Southeast Asia. Plectostoma was previously classified as a subgenus of Opisthostoma because of the deviation from regular coiling in many species in both taxa. This paper is the first of a two-part revision of the genus Plectostoma, and includes all non-Borneo species. In the present paper, we examined 214 collection samples of 31 species, and obtained 62 references, 290 pictures, and 155 3D-models of 29 Plectostoma species and 51 COI sequences of 19 species. To work with such a variety of taxonomic data, and then to represent it in an integrated, scaleable and accessible manner, we adopted up-to-date cybertaxonomic tools. All the taxonomic information, such as references, classification, species descriptions, specimen images, genetic data, and distribution data, were tagged and linked with cyber tools and web servers (e.g. Lifedesks, Google Earth, and Barcoding of Life Database. We elevated Plectostoma from subgenus to genus level based on morphological, ecological and genetic evidence. We revised the existing 21 Plectostoma species and described 10 new species, namely, P. dindingensis sp. n., P.mengaburensis sp. n., P. whitteni sp. n., P. kayiani sp. n., P. davisoni sp. n., P. relauensis sp. n., P. kubuensis sp. n., P. tohchinyawi sp. n., P. tenggekensis sp. n., and P. ikanensis sp. n. All the synthesised, semantic-tagged, and linked taxonomic information is made freely and publicly available online.
Systematic review of diplommatinid land snails (Caenogastropoda, Diplommatinidae) endemic to the Palau Islands. (1) Generic classification and revision of Hungerfordia species with highly developed axial ribs.
Yamazaki, Kazunori; Yamazaki, Midori; Ueshima, Rei
Diplommatinidae is a family of terrestrial caenogastropod snails that shows extensive species diversity and endemic radiation within the Palau (Belau) Islands. In this paper, we revised the taxonomy of Palauan endemic diplommatinids based on the comparative morphology of shell, operculum, radula, and genitalia. Although the generic classification of Palauan diplommatinids has been confusing, they are currently classified into two genera, Hungerfordia Beddome, 1889 and Palaina Semper, 1865. Palauan diplommatinids of these two genera are primarily distinguished by the radular, genital and operculum morphology. However, shell morphology, on which taxonomy has traditionally been based, does not provide definitive characters for generic identification, because shell shape and sculpture are highly variable within each genus. Although Hungerfordia has long been known as a monotypic genus, the current study redefines the endemic genus to include a wider range of species that were formerly placed in Diplommatina or Palaina. Following species are transferred to Hungerfordia: H. alata (Crosse, 1866) comb. nov.; H. lamellata (Crosse, 1866) comb. nov.; H. pyramis (Crosse, 1866) comb. nov.; H. ringens (Crosse, 1866) comb. nov.; H. polymorpha (Crosse, 1866) comb. nov.; H. inflatula (Crosse, 1866) comb. nov.; H. lutea (Beddome, 1889) comb. nov.; H. aurea (Beddome, 1889) comb. nov.; H. gibboni (Beddome, 1889) comb. nov.; H. crassilabris (Beddome, 1889) comb. nov. Pseudopalaina Moellendorff in Kobelt & Moellendorff, 1898 (synonym nov.) is demoted as a junior synonym of Hungerfordia. Palaina is also redefined based on the internal shell features and operculum morphology, in addition to the external shell characters. Furthermore, Eupalaina Kobelt & Moellendorff, 1898 is restored as a subgenus of Palaina for Palauan species on the basis of a genital character. The taxonomy of Hungerfordia species with highly developed axial ribs is revised. H. pelewensis Beddome, 1889, H. lamellata (Crosse, 1866) comb. nov., and H. alata (Crosse, 1866) comb. nov. are redescribed with new morphological data. Following new taxa are described: H. triplochilus sp. nov., H. expansilabris sp. nov., H. nudicollum sp. nov., H. echinata echinata sp. et subsp. nov., H. echinata tubulispina subsp. nov., H. elegantissima sp. nov., H. goniobasis goniobasis sp. et subsp. nov., H. goniobasis dmasechensis subsp. nov., H. subalata sp. nov., H. pteropurpuroides sp. nov., H. papilio papilio sp. et subsp. nov., H. papilio stenoptera subsp. nov.. PMID:25113222
Hershler, Robert; Liu, Hsiu-Ping; Bradford, Corbin
We describe three new species of springsnails (genus Pyrgulopsis) from the Amargosa River basin, California and Nevada (P. licina sp. n., P. perforata sp. n., P. sanchezi sp. n.), each of which was previously considered to be part of P. micrococcus. We also restrict P. micrococcus to its type locality area (Oasis Valley) and redefine a regional congener, P. turbatrix, to include populations from the central Death Valley region and San Bernardino Mountains that had been previously identified as P. micrococcus. The five species treated herein form genetically distinct lineages that differ from each other by 4.2-12.6% for mtCOI and 5.2-13.6% for mtNDI (based on previously published and newly obtained data), and are diagnosable by shell and/or penial characters. The new molecular data presented herein confirm sympatry of P. licina and P. sanchezi in Ash Meadows (consistent with morphological evidence) and delineate an additional lineage of P. micrococcus (in the broad sense) that we do not treat taxonomically owing to the paucity of morphological material. Conservation measures are needed to ensure the long term persistence of populations of P. micrococcus and a genetically differentiated lineage of P. sanchezi which live in disturbed habitats on private lands. PMID:24146554
Complexo Littorina ziczac (Gmelin) (Mollusca, Gastropoda, Caenogastropoda) no litoral fluminense: análise morfométrica, distribuição vertical e bioquímica The Littorina ziczac (Gmelin) complex (Mollusca, Gastropoda, Caenogastropoda) in the Rio de Janeiro coast: morphometric analysis, vertical distribution and biochemistry
Ricardo Silva Absalão; Renata Alves Pinheiro Roberg
The Littorina ziczac (Gmelin, 1791) species complex was studied in Rio de Janeiro State, southeastern Brazil. The occurrence of three species was confirmed, through the analysis of penis morphology: L. ziczac (Gmelin, 1791), L. lineata d'Orbigny, 1841 and L. lineolata d'Orbigny, 1840. There is a correlation between the morphology of the penis and shell shape, thus it was possible to make a discrimination model based in conchologic data, with an efficiency of 75%. However, this model cannot be...
... States (August 18, 2009; 74 FR 41649); thus, these three species are not included in this finding. In the... from the phylum Mollusca, class Gastropoda, superorder Caenogastropoda (Bouchet and Rocroi 2005, pp....
Literák, I.; Heneberg, P.; Sitko, J.; Wetzel, E. J.; Callirgos, J. M. C.; Čapek, Miroslav; Basto, D. V.; Papoušek, I.
Roč. 62, č. 4 (2013), s. 390-396. ISSN 1383-5769 R&D Projects: GA AV ČR IAA601690901; GA MŠk LC06073 Institutional support: RVO:68081766 Keywords : Birds * Caenogastropoda * Digenea * DNA analysis * Echinostomida * Eye trematode * Fluke Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.111, year: 2013
Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands
Yam, Rita S. W.; Yen-Tzu Fan; Tzu-Ting Wang
Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feedin...
Cugat Melich, Ignasi; Català Forner, Maria del Carme
The apple snail is a freshwater aquatic gasteropod mollusc that belongs to the Ampullariidae family. It is considered one of the 100 more harmful invasive species in the world and it has caused ravage in numerous ricefields around the world. In 2009 the first individuals of the plague were starting to be seen was seen in the ricefields of Delta de l'Ebre, nowadays the plague has already colonized most of the part of the left hemidelta and a small part of the right hemidelta. The calcium cyana...
Full Text Available Abstract Background Gastropod mitochondrial genomes exhibit an unusually great variety of gene orders compared to other metazoan mitochondrial genome such as e.g those of vertebrates. Hence, gastropod mitochondrial genomes constitute a good model system to study patterns, rates, and mechanisms of mitochondrial genome rearrangement. However, this kind of evolutionary comparative analysis requires a robust phylogenetic framework of the group under study, which has been elusive so far for gastropods in spite of the efforts carried out during the last two decades. Here, we report the complete nucleotide sequence of five mitochondrial genomes of gastropods (Pyramidella dolabrata, Ascobulla fragilis, Siphonaria pectinata, Onchidella celtica, and Myosotella myosotis, and we analyze them together with another ten complete mitochondrial genomes of gastropods currently available in molecular databases in order to reconstruct the phylogenetic relationships among the main lineages of gastropods. Results Comparative analyses with other mollusk mitochondrial genomes allowed us to describe molecular features and general trends in the evolution of mitochondrial genome organization in gastropods. Phylogenetic reconstruction with commonly used methods of phylogenetic inference (ME, MP, ML, BI arrived at a single topology, which was used to reconstruct the evolution of mitochondrial gene rearrangements in the group. Conclusion Four main lineages were identified within gastropods: Caenogastropoda, Vetigastropoda, Patellogastropoda, and Heterobranchia. Caenogastropoda and Vetigastropoda are sister taxa, as well as, Patellogastropoda and Heterobranchia. This result rejects the validity of the derived clade Apogastropoda (Caenogastropoda + Heterobranchia. The position of Patellogastropoda remains unclear likely due to long-branch attraction biases. Within Heterobranchia, the most heterogeneous group of gastropods, neither Euthyneura (because of the inclusion of P
Vermeulen, Jaap J.; Liew, Thor-Seng; Schilthuizen, Menno
Abstract We present reviews of the Sabah (Malaysia, on the island of Borneo) species of the following problematical genera of land snails (Mollusca, Gastropoda): Acmella and Anaglyphula (Caenogastropoda: Assimineidae); Ditropopsis (Caenogastropoda: Cyclophoridae); Microcystina (Pulmonata: Ariophantidae); Philalanka and Thysanota (Pulmonata: Endodontidae); Kaliella, Rahula, (Pulmonata: Euconulidae); Trochomorpha and Geotrochus (Pulmonata: Trochomorphidae). Next to this, we describe new species in previously revised genera, such as Diplommatina (Diplommatinidae); Georissa (Hydrocenidae); as well as some new species of genera not revised previously, such as Japonia (Cyclophoridae); Durgella and Dyakia (Ariophantidae); Amphidromus, and Trachia (Camaenidae); Paralaoma (Punctidae); Curvella (Subulinidae). All descriptions are based on the morphology of the shells. We distinguish the following 48 new species: Acmella cyrtoglyphe, Acmella umbilicata, Acmella ovoidea, Acmella nana, Acmella subcancellata, Acmella striata, and Anaglyphula sauroderma (Assimineidae); Ditropopsis davisoni, Ditropopsis trachychilus, Ditropopsis constricta, Ditropopsis tyloacron, Ditropopsis cincta, and Japonia anceps (Cyclophoridae); Diplommatina bidentata and Diplommatina tylocheilos (Diplommatinidae); Georissa leucococca and Georissa nephrostoma (Hydrocenidae); Durgella densestriata, Dyakia chlorosoma, Microcystina microrhynchus, Microcystina callifera, Microcystina striatula, Microcystina planiuscula, and Microcystina physotrochus (Ariophantidae); Amphidromus psephos and Trachia serpentinitica (Camaenidae); Philalanka tambunanensis, Philalanka obscura, Philalanka anomphala, Philalanka rugulosa, and Philalanka malimgunung (Endodontidae); Kaliella eurytrochus, Kaliella sublaxa, Kaliella phacomorpha, Kaliella punctata, Kaliella microsoma, Rahula delopleura, (Euconulidae); Paralaoma angusta (Punctidae); Curvella hadrotes (Subulinidae); Trochomorpha trachus, Trochomorpha haptoderma, Trochomorpha
Winnepenninckx, B; Steiner, G; Backeljau, T; De Wachter, R
Some generally accepted viewpoints on the phylogenetic relationships within the molluscan class Gastropoda are reassessed by comparing complete 18S rRNA sequences. Phylogenetic analyses were performed using the neighbor-joining and maximum parsimony methods. The previously suggested basal position of Archaeogastropoda, including Neritimorpha and Vetigastropoda, in the gastropod clade is confirmed. The present study also provides new molecular evidence for the monophyly of both Caenogastropoda and Euthyneura (Pulmonata and Opisthobranchia), making Prosobranchia paraphyletic. The relationships within Caenogastropoda and Euthyneura data turn out to be very unstable on the basis of the present 18S rRNA sequences. The present 18S rRNA data question, but are insufficient to decide on, muricacean (Neogastropoda), neotaenioglossan, pulmonate, or stylommatophoran monophyly. The analyses also focus on two systellommatophoran families, namely, Veronicellidae and Onchidiidae. It is suggested that Systellommatophora are not a monophyletic unit but, due to the lack of stability in the euthyneuran clade, their affinity to either Opisthobranchia or Pulmonata could not be determined. PMID:9479694
Regina Maria de Fraga Alberto
Full Text Available In order to verify the occurrence of invetebrates associated with macro clusters of Limnoperna fortunei (Dunker, 1857 formed on branches of “sarandi” (Chephalanthus glabratus (Spreng. K. Schum, quantitative samplings (N=28 were conducted for two years (2002 to 2004 at Veludo Beach on Guaíba Lake (municipality of Porto Alegre, RS, Brazil. From the results, the gastropod Heleobia piscium (Orbigny, 1835 was identified as a constant (78.57% species, while Potamolithus jacuyensis Pilsbry 1899 (35.71% and the crustaceous Hyalella curvispina Shoemaker 1942 (26% were indicated as accessory species. The other taxa were accidental (<25%: Ampullariidae (young individuals, Heleobia davisi (Silva & Thomé, 1985, Chilina parva (Martens, 1868 and Corbicula fluminea (Müller, 1774. Currently, the interspecific relationships among these taxa are poorly known.
Winnepenninckx, B; Backeljau, T; De Wachter, R
The 18S rRNA sequences of 12 molluscs, representing the extant classes Gastropoda, Bivalvia, Polyplacophora, Scaphopoda, and Caudofoveata, were determined and compared with selected known 18S rRNA sequences of Metazoa, including other Mollusca. These data do not provide support for a close relationship between Platyhelminthes (Turbellaria) and Mollusca, but rather suggest that the latter group belongs to a clade of eutrochozoan coelomates. The 18S rRNA data fail to recover molluscan, bivalve, or gastropod monophyly. However, the branching pattern of the eutrochozoan phyla and classes is unstable, probably due to the explosive Cambrian radiation during which these groups arose. Similarly, the 18S rRNA data do not provide a reliable signal for the molluscan interclass relationships. Nevertheless, we obtained strong preliminary support for phylogenetic inferences at more restricted taxonomic levels, such as the monophyly of Polyplacophora, Caenogastropoda, Euthyneura, Heterodonta, and Arcoida. PMID:8952075
Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands.
Yam, Rita S W; Fan, Yen-Tzu; Wang, Tzu-Ting
Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents. PMID:26927135
Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands
Rita S. W. Yam
Full Text Available Pomacea canaliculata (Ampullariidae has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents.
Horgan, Finbarr G.; Stuart, Alexander M.; Kudavidanage, Enoka P.
At least 14 species of apple snail (Ampullariidae) have been released to water bodies outside their native ranges; however, less than half of these species have become widespread or caused appreciable impacts. We review evidence for the impact of apple snails on natural and managed wetlands focusing on those studies that have elucidated impact mechanisms. Significant changes in wetland ecosystems have been noted in regions where the snails are established: Two species in particular (Pomacea canaliculata and Pomacea maculata) have become major pests of aquatic crops, including rice, and caused enormous increases in molluscicide use. Invasive apple snails have also altered macrophyte community structure in natural and managed wetlands through selective herbivory and certain apple snail species can potentially shift the balance of freshwater ecosystems from clear water (macrophyte dominated) to turbid (plankton dominated) states by depleting densities of native aquatic plants. Furthermore, the introductions of some apple snail species have altered benthic community structure either directly, through predation, or indirectly, through exploitation competition or as a result of management actions. To date much of the evidence for these impacts has been based on correlations, with few manipulative field or mesocosm experiments. Greater attention to impact monitoring is required, and, for Asia in particular, a landscape approach to impact management that includes both natural and managed-rice wetlands is recommended.
Rundell, Rebecca J
The endemic diplommatinid land snails (Caenogastropoda: Mollusca) of Belau (Republic of Palau, Micronesia) are an exceptionally diverse group of largely undescribed species distributed among rock and leaf litter habitats on most of Belau's 586 islands. Diplommatinid shell morphology (e.g. shell sculpture) reflects habitat type. In this study, I analysed a subset of the 90 diplommatinid species representing a broad geographical spread of islands in order to reveal the species' phylogenetic relationships and biogeography within the Belau archipelago. Diplommatinid species from the islands of Yap, Pohnpei, Kosrae and Guam are also included in the analysis. One nuclear (28S rRNA) and two mitochondrial (16S rRNA, COI) gene regions comprising 1906bp were used for phylogenetic reconstruction. Results show that (i) the Belau Diplommatinidae are not monophyletic, as Guam and Yap species should be included as part of the radiation, (ii) Pohnpei and Kosrae species are highly divergent from Belau diplommatinids, (iii) there is little evidence for in situ radiation within individual Belau islands, (iv) spined and heavily calcified rock-dwelling species form a well-supported clade, and (v) Belau diplommatinid genera are in need of revision. PMID:18765361
In this work we presented a comparative analysis of the mitochondrial genomes in gastropods. Nucleotide and amino acids composition was calculated and a comparative visual analysis of the start and termination codons was performed. The organization of the genome was compared calculating the number of intergenic sequences, the location of the genes and the number of reorganized genes (breakpoints) in comparison with the sequence that is presumed to be ancestral for the group. In order to calculate variations in the rates of molecular evolution within the group, the relative rate test was performed. In spite of the differences in the size of the genomes, the amino acids number is conserved. The nucleotide and amino acid composition is similar between Vetigastropoda, Ceanogastropoda and Neritimorpha in comparison to Heterobranchia and Patellogastropoda. The mitochondrial genomes of the group are very compact with few intergenic sequences, the only exception is the genome of Patellogastropoda with 26,828 bp. Start codons of the Heterobranchia and Patellogastropoda are very variable and there is also an increase in genome rearrangements for these two groups. Generally, the hypothesis of constant rates of molecular evolution between the groups is rejected, except when the genomes of Caenogastropoda and Vetigastropoda are compared.
María José Miranda
Full Text Available Se realizó un inventario y se analizaron parámetros de diversidad de la malacofauna terrestre del Parque Biológico Sierra de San Javier. Se llevaron a cabo muestreos cualitativos y cuantitativos en parcelas de 10x10m tomadas en transectas altitudinales, para un total de 22 169 especímenes recolectados. Las identificaciones taxonómicas se llevaron a cabo a nivel de especie. Se construyó una matriz de especies por parcela para analizar patrones de diversidad y se utilizaron estimadores no paramétricos (ICE, ACE, Chao 1 y Chao 2 para calcular la diversidad del Parque, el grado de completitud del muestreo y la agregación espacial de los datos. Se calcularon los índices de Shannon, Simpson, Whittaker y Jaccard. La riqueza del Parque fue estimada en 32 especies distribuidas en 21 géneros y 13 familias. Solo una especie pertenece a Caenogastropoda, el resto son Pulmonados Stylommatophora y Systellommatophora. La familia más representada fue Charopidae mientras que la especie con mayor abundancia relativa fue Adelopoma tucma. La riqueza y diversidad fue levemente mayor en chaco seco que en bosque húmedo de Yungas. Los valores de diversidad obtenidos fueron elevados en comparación con estudios previos realizados en el noroeste Argentino.
Oliveira-Filho, E C; Paumgartten, F J
The toxicity of Euphorbia milii molluscicidal latex and niclosamide (NCL) to target snails (Biomphalaria glabrata and Biomphalaria tenagophila) and nontarget aquatic organisms is evaluated. Planorbidae snails were killed by very low concentrations of lyophilized latex (48-h LC(50), mg/L: B. glabrata, 0.12; B. tenagophila, 0.09; Helisoma duryi, 0.10). Latex was less toxic (48-h LC(50) or EC(50), mg/L) to oligochaeta (Tubifex tubifex, 0.31), planktonic crustacea (Daphnia similis, 0.38; C. dubia, 1.07; Artemia sp., 0.93), and fishes (Danio rerio, 0.96; Poecilia reticulata, 1. 39), and considerably less toxic to Ampullariidae snails (Pomacea sp. , 10.55) and frog tadpoles (Rana catesbeiana, 7.50). Latex (up to 100 mg/L) was not toxic to bacteria (P. putida and V. fischeri), algae (Selenastrum capricornutum and Chlorella vulgaris), and mosquito larvae (Anopheles albitarsis, Aedes aegypti, Aedes fluviatilis). NCL was very toxic (48-h LC(50) or EC(50), mg/L) to Planorbidae snails (B. glabrata, 0.15, B. tenagophila, 0.13; H. duryi, 0.10), T. tubifex (0.11), crustacea (D. similis, 0.19; Ceriodaphnia dubia, 0.47; Artemia sp. 0.18), fishes (D. rerio, 0.25; P. reticulata, 0.29), R. catesbeiana (0.16), and Pomacea sp. (0.76). NCL was toxic to bacteria, algae (96-h IC(50), mg/L: S. capricornutum, 0.34; C. vulgaris, 1.23) and slightly toxic to mosquito larvae. In conclusion, E. milii latex, as compared with the reference molluscicide niclosamide, presents a higher degree of selectivity toward snails which are intermediate hosts of Schistosoma trematodes. PMID:10903832
W. Lobato Paraense
Full Text Available É registrado o primeiro encontro do molusco planorbideo Biomphalaria glabrata, hospedeiro intermediário do Schistosoma mansoni, no Estado do Piauí, coletado em vários criadouros na cidade de Parnaíba. O exame de 694 exemplares revelou a presença de formas evolutivas de algumas espécies de trematodeos, mas não de Schistosomatidea. Nenhum caso autoctone de xistosomose foi até agora identificado na população humana da cidade. A presença da B. glabrata em Parnaíba amplia em 20 km para leste a área de sua distribuição na Região Litoral Norte da Grande Região Nordeste do Brasil onde era conhecida até em Avaioses no extremo leste da parte maranhense da referida Região. Outros moluscos também coletados nos mesmos criadouros foram Biomphalaria straminea, Drepanotrema lucidum. D. cimex, D. depressissimum, Physidae e Ampullarriidae.The occurrence of Biomphalaria glabrata is recorded for the first time in the state of Piauí, where it was collected from several breeding places in the city of Parnaíba. Examination of 694 specimens showed that a part of them were infected with trematodes other than Schistosomatidae. So far no autochthonous cases of schistosomiasis have been identified in the city. The presence of B. glabrata in Parnaíba extends by 20 Km eastward its range on the Northern Coastal region of the Great Northeastern region of Brazil, where it had been found as far as Araioses, on the eastern extreme of the state of Maranhão. Other snail species collected from the same breeding places were Biomphalaria straminea, Drepanotrema lucidum, D. cimex, D. depressissimum, Physidae and Ampullariidae.
Sothorn Anucherngchai; Thanawan Tejangkura; Thapana Chontananarth
Objective: To investigate the prevalence of cercarial trematode infection in snails and to examine the reconstruction of the phylogenetic relationship to explain the molecular system of cercarial stage trematodes to estimate the infection rate of in the definite host from the Chao-Phraya Basin. Methods: The snails were collected from 10 provinces of the Chao-Phraya Basin, Thailand by stratified sampling method. The snails were examined for cercarial infection by the crushing method. All DNA specimens were amplified with internal transcribed spacer 3 (ITS3) and ITS4 primer based on PCR technique. The sequence data were aligned and used to reconstruct the phylogenetic tree by unweighted pair-group method with arithmetic means with 10 000 bootstraps. Results: The overall rate of cercarial infection was found to be 5.90%(122/2 067). Snails in the family Thiaridae were found to be in the highest prevalence followed by Lym-naeidae, Bithyniidae, Planorbidae, Viviparidae, and Ampullariidae, respectively, while the Buccinidae family (Clea helena) did not reveal any infections. The frequently found species of cercariae were parapleurolophocercous cercariae, cercariae and megarulous cercariae. The monophyletic tree separated the snails into five groups comprised of Heterophyidae, Strigeidae, Lecithodendriidae, Philophthalmidae and Echinostomatidae using the sequence of Angiostrongylus cantonensis as an out-group. Conclusions: This study was the first to report on cercarial infection in the Chao-Phraya Basin, Thailand. This revealed that a high variety of freshwater snails were infected by cercariae stage trematodes with a high prevalence. The sequence data of ITS2 can be used to investigate the phylogenetic relationships of trematodes at the family level and in each clade of different families separated by the definitive hosts.
Colin H Kyle
Full Text Available Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and
Sevigny, Joseph L; Kirouac, Lauren E; Thomas, William Kelley; Ramsdell, Jordan S; Lawlor, Kayla E; Sharifi, Osman; Grewal, Simarvir; Baysdorfer, Christopher; Curr, Kenneth; Naimie, Amanda A; Okamoto, Kazufusa; Murray, James A; Newcomb, James M
, Caenogastropoda, and Heterobranchia) were all monophyletic, and thus appear to be better classifications for this diverse group. PMID:25996944
Joseph L Sevigny
, Neritimorpha, Caenogastropoda, and Heterobranchia were all monophyletic, and thus appear to be better classifications for this diverse group.
Rumi, Alejandra; Gregoric, Diego E Gutiérrez; Núñez, Verónica; Darrigran, Gustavo A
A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km2 is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Buenos Aires; Museo de La Plata, La Plata and Fundación "Miguel Lillo", Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country
Full Text Available This catalogue of 194 gastropod taxa is based on the collection of Danian gastropods from the Baunekule facies, Faxe Formation in eastern Denmark. The gastropod fauna is extremely rich and well preserved. Most of the gastropods (106 species are referred to genus level only, 9 morphotypes to even higher taxonomical levels and 79 gastropods are referred to species level. The gastropods are classified following Bouchet & Rocroi (2005 as 4 different clades: Vetigastropoda (represented by 26 species and 10 superfamilies, Caenogastropoda (represented by 142 species and 17 superfamilies, Heterobranchia (represented by 23 species and 5 superfamilies and Opisthobranchia (represented by 1 species and 1 superfamily. The new species Zaclys? nuetzeli n. sp. is introduced. The Faxe Formation is recognised as a cold-water coral ecosystem with interfingering smaller bryozoan mounds. The Baunekule facies is found in the upper part of the coral mound complex of the Faxe Formation, where it forms isolated lensoidal bodies in the flanks of some of the coral mounds. It is characterised by a high diversity invertebrate fauna that occurs in weakly consolidated coraldominated floatstone to rudstone. The diagenesis of the Baunekule facies is of special significance because a high proportion of the originally aragonite-shelled fauna is preserved by recrystallization to calcite during early burial diagenesis. Most of the gastropods are not known from other parts of the Faxe Fm. The fauna is very important for comparative evolutionary studies of fossil and modern gastropods on cold-water coral mounds. Many of the genera have not previously been recorded from Danian strata. None of the gastropod species found in the Baunekule facies are known for certain to range below the Cretaceous–Palaeogene boundary. The fauna is comparable to gastropods found on modern cold-water coral mounds in the North Atlantic. The gastropod fauna from the Baunekule facies is characterised by a