Malacologia

Xenophora (Xenophora) crispa (konig, 1825) (Gastropoda: Xenophoridae) is a marine mollusc with a shell of medium size and with wide geographical and bathymetric distribution. In this work are provided biometric unpublished data on this species that is compared with X. (X.) senegalensis P. Fischer, 1873, the species more similar morphologically.

Se presenta una síntesis y nueva información sobre
faunística, distribución, taxonomía y conservación de la
malacofauna uruguaya de Gastropoda marinos y
estuarinos costeros bentónicos (0-50 m). La misma está
compuesta por al menos 140 especies, de las cuales solo
siete son estuarinas (incluyendo las exóticas Rapana venosa
y Myosotella myosotis). Los géneros Olivancillaria (Olividae)
y Buccinanops (Nassariidae) son particularmente diversos
en especies y están distribuidos en una variedad de
fondos inconsolidados. En el Río de la Plata y y otros
ambientes estuariales el género Heleobia (Cochliopidae)
está ampliamente distribuido y es considerado aquí como
máxima prioridad de investigación. Otros grupos prioritarios
son aquellos generalmente compuestos por
microgasterópodos que poseen diversos grados de asociación
y simbiosis con poríferos, antozoos, poliquetos,
crustáceos, equinodermos y briozoos (Epitoniidae,
Eulimidae, Triphoridae, Cerithiopsidae, Pyramidellidae
y Nudibranchia), así como Trochoidea y Vitrinellidae. Se
insiste en la necesidad de nuevas técnicas de muestreo y
enfoques de investigación, formación de colecciones y
recursos humanos como elementos particularmente críticos
para llenar vacíos de información. El manejo adecuado
del agua de lastre y del químico tributiltina (TBT),
la reglamentación y control de la extracción de algunas
especies, la implementación de áreas protegidas y el enfoque
ecosistémico en pesquerías son considerados de
particular relevancia para la conservación de esa fauna.

We provide here a catalogue of all available species nomina of Orthalicoidea occurring in Argentina. Ongoing taxonomic revisions on the genera Bostryx Troschel, 1847, Clessinia Doering, 1874, Pilsbrylia Hylton Scott, 1952, and Spixia Pilsbry & Vanatta, 1898, highlighted the necessity of an updated catalogue for the region. A total of 101 orthalicoidean species classified into four families, Bothriembryontidae, Bulimulidae, Odontostomidae and              Simpulopsidae are present in Argentina. The catalogue provided here is based on examination of primary literature, available revisions and monographs, comparative studies within and among
species and revision of museum data, including most type specimens. Additional collection of specimens in various localities of the country was carried out for more than a decade to be
able to accurately state distributional information on the species treated. Nomenclatural details are provided for all nominal species. Name-bearing types were located for 86 species-group
taxa, and six lectotypes were designated for the stabilization of the taxonomy. We propose the following nine new combinations: Bulimulus fourmiersi (d’Orbigny, 1835), Clessinia cordovana (Pfeiffer, 1855), Drymaeus flossdorfi (Holmberg, 1909), Cyclodontina (Ventania) avellanedae (Doering, 1881), Simpulopsis (Eudioptus) eudioptus (Ihering in Pilsbry, 1897),
Spixia champaquiana (Doering, 1875), S. charpentieri (Grateloup in Pfeiffer, 1850), S. minor (d’Orbigny, 1837) and S. parodizi (Hylton Scott, 1951). The following four new synonymies are
proposed: Bostryx sophieae Breure, 1979, with Bulimus cordillerae (Strobel, 1874) (current name Bostryx cordillerae); Cyclodontina (Clessinia) gracilis Hylton Scott, 1956, with Bulimus
cordovanus Pfeiffer, 1855 (current name Clessinia cordovana); Spixia estherae Fernández, 1971, with Odontostomus (Spixia) costellifer Hass, 1936 (current name Spixia costellifer);
Kuschelenia simulans Hylton Scott, 1951, with Helix tupacii d’Orbigny, 1835 (current name Scutalus tupacii). Bulimulus sporadicus gracilis Hylton Scott, 1948, is changed from subspecific to specific status.
Key words: South America, Pulmonata, Stylommatophora, available nomina.

A synthesis and new data on faunistics, distribution, taxonomy and conservation of the Uruguayan malacofauna of coastal benthic marine (0-50 m) and estuarine Gastropoda is presented. It is composed by at least 140 species, of which only seven are estuarine (including the exotics Rapana venosa and Myosotella myosotis). The genera Olivancillaria (Olividae) and Buccinanops (Nassariidae) are particularly well represented and distributed in varied unconsolidated bottoms. In the the Río de la Plata and other ...

During the study of the Pliocene malacofaunas of the Mediterranean Basin, it was ascertained that the name Spondylus ferreolensis Fontannes, 1882 cannot be used as a substitute for S. concentricus Bronn, 1831 of which the type material is here represented for the first time. The validity of Acanthocardia perrugosa (Fontannes, 1882) is also proposed, of which it was possible to view the type material, a species previously considered synonymous with A. paucicostata (GB Sowerby, 1841), or A. bianconiana (Cocconi, 1873) or A. aculeata (Linnaeus, 1758).

En el presente trabajo de Tesis se realizó un estudio filogeográfico sobre las especies endémicas y amenazadas del género Aylacostoma Spix, 1827 de la región del Alto Paraná (Argentina-Paraguay) enfocado en comprender la estructura genética e historia de sus poblaciones, con el fin último de aportar información fundamental para el desarrollo de estrategias de conservación y manejo de las especies. En la década de 1950 fueron formalmente descriptas tres especies para esta región, las que habitaban ambientes altamente oxigenados del río Paraná como lo eran los rápidos del Apipé, sitio actual de emplazamiento de la Represa Binacional Yacyretá. La construcción y llenado de Yacyretá, provocó un cambio ambiental drástico y nocivo para la subsistencia de estas especies, y en la actualidad se encuentran catalogadas en la Lista Roja de las Especies Amenazadas como “extinguidas en la naturaleza”. Al presente, dos de las formas pueden considerarse extintas: A. guaraniticum (Hylton Scott, 1953) y A. stigmaticum (Hylton Scott, 1954). Sin embargo, A. chloroticum Hylton Scott, 1954 aún persiste en la naturaleza aunque en situación crítica. De esta manera, y a los efectos de recabar la mayor información posible sobre las especies del Alto Paraná, en el presente trabajo se utilizaron básicamente tres ejes de análisis: conchillas, caracteres endosomáticos y secuencias de ADN mitocondrial.

Diverse biogeographic regions have been proposed in Argentina using different approaches of biogeography and different criteria. However, none of these proposals has considered freshwater gastropods in estimating biodiversity values, although gastropods from continental waters have great ecological importance and are a useful group to characterize freshwater environments. For this reason, our aim is to define freshwater gastropod provinces and to compare them with the available information on biogeographic regions previously defined using other data sets. The gastropod database comprises approximately 4,000 georeferenced records from museum collections, bibliographic records, and collections of our research team. A similarity analysis among basins was carried out using the species as characters and applying Jaccard's coefficient and UPGMA clustering with the MVSP program to obtain the resulting phenogram. Eight provinces were identified: I, Misionerean; II, Middle Paraná; III, Uruguay River; IV, Lower Paraná — Río de la Plata; V, Central; VI, Cuyo; VII, Northern Patagonia; and VIII, Southern Patagonia. Between Provinces V and VI lies a Transitional Zone that shows a higher faunal similarity with the Del Plata basin than with the Patagonian basins. The provinces with the highest diversity were I and IV (H = 1.92 and 1.89 respectively), while Province III shows the highest richness (S = 51) and quantity of endemic and vulnerable species. These provinces are the most densely populated in the country and therefore include the areas with the highest environmental degradation level.

Fósiles de Quitones (Mollusca: Polyplacophora) del Pleistoceno Medio (Formación Bermont) del sur de la Florida, EEUU. Edgardo A.R. Ortiz Corps y Cedar I. García Ríos. Departamento de Biología, Universidad de Puerto Rico en Humacao, Estación Postal CUH, 100 Carr 908, Humacao, PR 00791-4300 La formación Bermont fue depositada durante el Pleistoceno medio, entre 1.6 millones y 750 mil años antes del presente, al sur de la Florida, EE. UU. Petuch y Roberts (2007) han reconocido tres miembros de la formación con características estratigráficas y litológicas distintas. Dos de esos miembros representan condiciones de deposición marina, cuando el nivel del mar era más alto que el actual; el otro miembro contiene depósitos de agua dulce, cuando el nivel del mar era más bajo. El grupo mejor representado de fósiles en esta formación son los moluscos; sin embargo, no existe récord de poliplacóforos para la formación. La muestra de sedimentos estudiada, posiblemente del miembro superior de esa f...

This paper compiles the pre-Linnean iconography of freshwater mussels or naiads and provices an understanding of the historical framework in which they were created. The first book providing a figure of a freshwater mussel would seem to be Hortus sanitatis, an anonymous ...

The 46 names of species of marine bivalves and gastropods made available by Grabau & King in 1928 are discussed. Probable or possible type material for all but 13 of these taxa has been located in the Institute of Oceanology, Chinese Academy of Sciences. Of these taxa, nine are regarded as valid, the rest being junior synonyms. The valid taxa are: Verilarca interplicata, Collisella peitaihoensis, Rissoina barbara, Rissoina bureri, Epitonium scalare minor, Gradatiscala gradata pygmaea, Nassarius gregarius, Terebra bellanodosa and Mangelia dobsoni, all Grabau & King, 1928. Brief biographies of Amadeus William Grabau (1870-1946) and Chinese malacologist Sohtsu Gee King (1886-1949) are provided.

O presente estudo analisou a ocorrência e densidade populacional de Corbicula fluminea nas Unidades de Conservação: RPPN Mata do Uru, Parque Estadual de Vila Velha e APA do Rio Verde. Foram realizadas campanhas amostrais no período julho de 2016 a julho de 2017. A vistoria dos ambientes foi realizada por busca ativa e nos locais de ocorrência foi realizada demarcação de área de 1m2 para análise da densidade. As amostras foram fixadas em formol 10% e conservadas em etanol 70%. De cada exemplar, foram obtidas medidas
morfométricas das valvas para análises de correlação entre variáveis. Para a RPPN Mata do Uru foi registrada a ocorrência de C. fluminea com amplitude de classe de comprimento entre 7 e 23 mm e densidade
entre 11 e 47 ind./m2. Na APA do Rio Verde, a espécie apresentou amplitude de comprimento entre  13 e 25 mm e densidade de 331 ind./m2. No Parque Estadual de Vila Velha não houve registro de ocorrência da espécie  para os rios Guabiroba e Quebra Perna. Nos três ambientes vistoriados foram registradas populações de espécies nativas do gênero Diplodon e Anodontites. Considerando os efeitos da espécie invasora para o ambiente  e para a fauna de moluscos límnicos nativos recomenda-se o monitoramento contínuo da espécie para estas
UC’s e o estudo de seus efeitos para a densidade de bivalves nativos.

O material malacológico oriundo de escavação realizada no Sambaqui da Tarioba (Rio de Janeiro, Brasil) foi classificado e descrito pelos índices quantitativos tradicionais de zooarqueologia (NISP, MNI), bem como testada a hipótese de diferenças em riqueza e abundância de espécies ao longo das camadas arqueoestratigráficas. Datações de radiocarbono indicaram uma ocupação do Sambaqui da Tarioba de pelo menos 550 anos durante o Holoceno Recente (4070 - 3520 AP). Foram identificadas 34 espécies de moluscos, 18 bivalves e 16 gastrópodes, e
mais duas famílias pertencentes à classe Bivalvia (Mytilidae e Ostreidae). No total, foram amostrados 7360 NISP e 3675 MNI. Os Testes de Mann-Whitney indicaram diferenças significativas para os valores de MNI e NISP entre as camadas arqueoestratigráficas do Sambaqui da Tarioba, as quais podem ser explicadas por vieses culturais e fatores tafonômicos, ambientais e/ou outros fatores intrínsecos às populações de moluscos daquela época.

En este trabajo se presenta un ejemplar de concha de molusco marino recuperado como parte de un depósito funerario de época altoimperial. El elemento procede de una tumba excavada en la ciudad de Mérida (España). El análisis taxonómico indica su pertenencia a la especie Cypraea pantherina. Se trata de un elemento exótico de procedencia indopacífica incluido muy ocasionalmente en depósitos funerarios en el mundo romano desde el s. I a. C. La especie suele aparecer asociada a tumbas femeninas por sus connotaciones relativas a la fertilidad, la procreación y el buen parto. El caso emeritense es el único del que se tiene noticia hasta el momento en la Península Ibérica, permitiendo así ampliar nuestro conocimiento sobre la distribución de especies exóticas procedentes de mares lejanos mediante la actividad humana.

Schistosomiasis remains a major parasitic disease, endemic in large parts of South America. Five neotropical species of Biomphalaria have been found to act as intermediate hosts of Schistosoma mansoni in natural populations, while others have been shown to be susceptible in experimental infections, although not found infected in the field. Among these potential intermediate hosts, Biomphalaria peregrina represents the most widespread species in South America, with confirmed occurrence records from Venezuela to northern Patagonia. In this study, we report the southernmost record for the species at the Pinturas River, in southern Patagonia, which finding implies a southward reassessment of the limit for the known species of this genus. The identities of the individuals from this population were confirmed through morphological examination, and by means of two mitochondrial genes, cytochrome oxidase subunit I (COI) and 16S-rRNA. With both markers, phylogenetic analyses were conducted in order to compare the genetic background of individuals from the Pinturas River with previously genetically characterized strains of B. peregrina from various South-American locations. In addition, we produced a potential distribution model of B. peregrina in South America and identified the environmental variables that best predict that distribution. The model was estimated through a maximum entropy algorithm and run with occurrence points obtained from several sources, including the scientific literature and international databases, along with climatic and hydrographic variables. Different phylogenetic analyses with either the COI or 16S-rRNA sequences did not conflict, but rather gave very similar topological organizations. Two major groups were identified, with sequences from the Pinturas River grouping together with haplotypes from subtropical and temperate regions. The model developed had a satisfactory performance for the study area. We observed that the areas with higher habitat suitability were found to be mainly linked to subtropical and temperate regions of South America between 15° and 45° south latitude, with different moderate-and low-suitability areas outside this range. We also identified the coldest temperatures as the main predictors of the potential distribution of this snail. Susceptibility surveys wouldbe required to evaluate if southern populations of B. peregrina still retain their potential as intermediate hosts of S. mansoni.

The Atlantic Forest represents one of
the global priority eco-regions for biodiversity conservation. In Argentina, this is represented by the Paranense
Forest, which occupies much of the Misiones Province. In this paper, an updated list of land mollusks from
Misiones Province is presented, and its species richness was evaluated comparing protected and unprotected
areas. For this, we reviewed La Plata Museum Mollusk Collection, updated the literature review, and developed
some field work between 2009 and 2010. For the areographic work, a grid (50x50km) was applied to a
Misiones province map. In this region, large areas of native vegetation constituting the Paranaense Forest still
persist, and include protected areas such as the Iguazú National Park and Puerto Península Provincial Park.
These areas have been the most explored at the malacological level (both terrestrial and aquatic environments),
a fact that is consistent with the greater number of records found, which may also be the explanation for the
highest number of species recorded in the region. A database containing 497 records was compiled. The number
of species occurring in this Province was increased from 28 to 56; 11 of which were exotic species. A total of
38 of the species occurred in protected areas and 53 in unprotected areas; and 25 species were micro-mollusks.
Orthalicidae was the family with the highest species number (10) and the widest distribution, occupying 16/20
sampling units. Megalobulimus was the genus found in a greater number of sampling units (14/20). The highest
values of specific richness of land gastropods were found in Northern Misiones (R=32). This richness was
similar to that previously reported for the Tucumán Province, although species occurring in both provinces were
mostly different. The richness in Misiones Province border areas, as the Republic of Paraguay and the state of
Santa Catarina (Brazil), was about twice that found in the province. The present study showed the existence of
poorly explored areas at malacological level, especially in Central and Eastern Misiones. Data presented here
will allow focus future sampling efforts on such areas, so patterns of species distribution can be better defined