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Esperanza Parada - One of the best experts on this subject based on the ideXlab platform.

  • Nuclear DNA content in two Sphaeriidae species from Southern Chile (Bivalvia: Veneroida)
    Molluscan Research, 2017
    Co-Authors: Pedro Jara-seguel, Esperanza Parada, Santiago Peredo, Claudio Palma-rojas, Elisabeth Von Brand
    Abstract:

    ABSTRACTThe family Sphaeriidae is a group of cosmopolitan freshwater clams that inhabit temporary and permanent fluvial and lacustrine environments around the world. In Chile, Sphaeriidae is represented by 11 species belonging to the genera Musculium, Pisidium and Sphaerium. In this study, the nuclear DNA content (or 2C-value) of Musculium argentinum (d’Orbigny, 1835) and Pisidium llanquihuense Ituarte, 1999 was estimated for the first time. Musculium argentinum showed a 2C-value of 3.7 ± 0.38 pg, whereas P. llanquihuense showed a 2C-value of 3.57 ± 0.36 pg. These 2C-values are within the range previously reported for Sphaeriidae (2.35–5.7 pg), which includes diploids and polyploids, amounting to 13 of the species examined around the world. Of the cytological data available for the family, the nuclear DNA content can have a unifying role in understanding the magnitude of the chromosome polymorphisms within this polyploid complex.

  • gonadal organization and gametogenesis in musculium argentinum veneroida Sphaeriidae from a population in southern chile
    Journal of Shellfish Research, 2010
    Co-Authors: Santiago Peredo, Esperanza Parada, Pedro Jaraseguel, Elisabeth Von Brand
    Abstract:

    ABSTRACT The gonadal organization and cytological characteristics of gametogenesis in a population of the freshwater clam Musculium argentinum (d'Orbigny, 1835) are described. Sections of the rather small gonad demonstrate the existence of hermaphroditic specimens, and is composed of hermaphrodite follicles among the intestine coils in the posterior dorsal region of the body. Follicles contain male and female germ cells at different stages of maturation, which can be recognized by their shape, size, and nuclear features. Male germ cells are organized in cysts, and spermatocytes do carry out meiosis. Within follicles, male and female germ cells occupy different regions. Gonad activity throughout the year is coincident with the life cycle pattern of the M. argentinum population studied previously.

  • Nuclear DNA Content in Two Chilean Species of Pisidium (Veneroida: Sphaeriidae)
    Journal of Shellfish Research, 2010
    Co-Authors: Pedro Jara-seguel, Esperanza Parada, Santiago Peredo, Claudio Palma-rojas, Elisabeth Von Brand
    Abstract:

    ABSTRACT The pill clams Pisidium chilense (d'Orbigny, 1846) and Pisidium huillichum (Ituarte, 1999) showed a 2C DNA content of 4.04 ± 0.4 pg and 2.35 ± 0.24 pg, respectively. The somatic DNA content of these 2 Chilean Pisidium Pfeiffer 1821 species is within the range described previously for diploid Heterodonta, despite the fact that both showed a high chromosome number (> 100–120 chromosomes) equivalent to the polyploid level described for other species of the genus. The nuclear DNA content is shown here for the first time for species of the family Sphaeriidae. The Pisidium, like other species, are not economically important as edible species, but they play a significant role in the dynamics of nutrient and energy cycles in freshwater bodies similar to that described for other Sphaeriidae species.

  • registro de poliploidia en la almeja dulceacuicola musculium argentinum d orbigny 1835 Sphaeriidae veneroida
    Gayana, 2005
    Co-Authors: Pedro Jaraseguel, Santiago Peredo, Esperanza Parada
    Abstract:

    La poliploidia es un caracter inusual en moluscos bivalvos. Sin embargo, datos citogeneticos documentados para especies de la subfamilia Sphaeriinae (familia Sphaeriidae) del hemisferio norte muestran numeros cromosomicos que varian desde 36 hasta ca. 247. La almeja dulceacuicola Musculium argentinum (D'Orbigny 1835) presenta un numero cromosomico 2n = ca. 130, lo cual muestra que la poliploidia tambien estaria presente en esferidos sudamericanos. Estos antecedentes citogeneticos sugieren que Sphaeriinae podria constituir un complejo poliploide maduro

  • registro de poliploidia en la almeja dulceacuicola musculium argentinum d orbigny 1835 Sphaeriidae veneroida record of polyploidy in the freshwater clam musculium argentinum d orbigny 1835 Sphaeriidae veneroida
    2005
    Co-Authors: Pedro Jaraseguel, Santiago Peredo, Esperanza Parada
    Abstract:

    The polyploidy is an unusual character in bivalve mollusks. However, cytogenetic data documented for north-hemispheric species of the subfamily Sphaeriinae (family Sphaeriidae), showed chromosome numbers ranging from 36 to ca. 247. The freshwater clam Musculium argentinum (D‘Orbigny 1835) has a polyploid chromosome number 2n = ca. 130, which shows that polyploidy likewise may be present in South American sphaeriids. These cytogenetic data suggest that the subfamily Sphaeriinae could constitute a mature polyploid complex.

Santiago Peredo - One of the best experts on this subject based on the ideXlab platform.

  • Nuclear DNA content in two Sphaeriidae species from Southern Chile (Bivalvia: Veneroida)
    Molluscan Research, 2017
    Co-Authors: Pedro Jara-seguel, Esperanza Parada, Santiago Peredo, Claudio Palma-rojas, Elisabeth Von Brand
    Abstract:

    ABSTRACTThe family Sphaeriidae is a group of cosmopolitan freshwater clams that inhabit temporary and permanent fluvial and lacustrine environments around the world. In Chile, Sphaeriidae is represented by 11 species belonging to the genera Musculium, Pisidium and Sphaerium. In this study, the nuclear DNA content (or 2C-value) of Musculium argentinum (d’Orbigny, 1835) and Pisidium llanquihuense Ituarte, 1999 was estimated for the first time. Musculium argentinum showed a 2C-value of 3.7 ± 0.38 pg, whereas P. llanquihuense showed a 2C-value of 3.57 ± 0.36 pg. These 2C-values are within the range previously reported for Sphaeriidae (2.35–5.7 pg), which includes diploids and polyploids, amounting to 13 of the species examined around the world. Of the cytological data available for the family, the nuclear DNA content can have a unifying role in understanding the magnitude of the chromosome polymorphisms within this polyploid complex.

  • gonadal organization and gametogenesis in musculium argentinum veneroida Sphaeriidae from a population in southern chile
    Journal of Shellfish Research, 2010
    Co-Authors: Santiago Peredo, Esperanza Parada, Pedro Jaraseguel, Elisabeth Von Brand
    Abstract:

    ABSTRACT The gonadal organization and cytological characteristics of gametogenesis in a population of the freshwater clam Musculium argentinum (d'Orbigny, 1835) are described. Sections of the rather small gonad demonstrate the existence of hermaphroditic specimens, and is composed of hermaphrodite follicles among the intestine coils in the posterior dorsal region of the body. Follicles contain male and female germ cells at different stages of maturation, which can be recognized by their shape, size, and nuclear features. Male germ cells are organized in cysts, and spermatocytes do carry out meiosis. Within follicles, male and female germ cells occupy different regions. Gonad activity throughout the year is coincident with the life cycle pattern of the M. argentinum population studied previously.

  • Nuclear DNA Content in Two Chilean Species of Pisidium (Veneroida: Sphaeriidae)
    Journal of Shellfish Research, 2010
    Co-Authors: Pedro Jara-seguel, Esperanza Parada, Santiago Peredo, Claudio Palma-rojas, Elisabeth Von Brand
    Abstract:

    ABSTRACT The pill clams Pisidium chilense (d'Orbigny, 1846) and Pisidium huillichum (Ituarte, 1999) showed a 2C DNA content of 4.04 ± 0.4 pg and 2.35 ± 0.24 pg, respectively. The somatic DNA content of these 2 Chilean Pisidium Pfeiffer 1821 species is within the range described previously for diploid Heterodonta, despite the fact that both showed a high chromosome number (> 100–120 chromosomes) equivalent to the polyploid level described for other species of the genus. The nuclear DNA content is shown here for the first time for species of the family Sphaeriidae. The Pisidium, like other species, are not economically important as edible species, but they play a significant role in the dynamics of nutrient and energy cycles in freshwater bodies similar to that described for other Sphaeriidae species.

  • registro de poliploidia en la almeja dulceacuicola musculium argentinum d orbigny 1835 Sphaeriidae veneroida
    Gayana, 2005
    Co-Authors: Pedro Jaraseguel, Santiago Peredo, Esperanza Parada
    Abstract:

    La poliploidia es un caracter inusual en moluscos bivalvos. Sin embargo, datos citogeneticos documentados para especies de la subfamilia Sphaeriinae (familia Sphaeriidae) del hemisferio norte muestran numeros cromosomicos que varian desde 36 hasta ca. 247. La almeja dulceacuicola Musculium argentinum (D'Orbigny 1835) presenta un numero cromosomico 2n = ca. 130, lo cual muestra que la poliploidia tambien estaria presente en esferidos sudamericanos. Estos antecedentes citogeneticos sugieren que Sphaeriinae podria constituir un complejo poliploide maduro

  • registro de poliploidia en la almeja dulceacuicola musculium argentinum d orbigny 1835 Sphaeriidae veneroida record of polyploidy in the freshwater clam musculium argentinum d orbigny 1835 Sphaeriidae veneroida
    2005
    Co-Authors: Pedro Jaraseguel, Santiago Peredo, Esperanza Parada
    Abstract:

    The polyploidy is an unusual character in bivalve mollusks. However, cytogenetic data documented for north-hemispheric species of the subfamily Sphaeriinae (family Sphaeriidae), showed chromosome numbers ranging from 36 to ca. 247. The freshwater clam Musculium argentinum (D‘Orbigny 1835) has a polyploid chromosome number 2n = ca. 130, which shows that polyploidy likewise may be present in South American sphaeriids. These cytogenetic data suggest that the subfamily Sphaeriinae could constitute a mature polyploid complex.

Peruzzo Rubén - One of the best experts on this subject based on the ideXlab platform.

  • Aplicación de índices de calidad de agua en un arroyo pampeano utilizando macroinvertebrados bentónicos como bioindicadores (Gualeguaychú, Entre Ríos, Argentina)
    2014
    Co-Authors: Crettaz-minaglia, Melina C., Aguer Irene, Borro Esteban, Juárez Ricardo, Peruzzo Rubén
    Abstract:

    Water quality can be evaluated through a set of physical, chemical and environmental variables that characterize the water body under study. These variables, along with the climate impact,hydrological regime and land use, determine the diversity of organisms. Santa Barbara Stream is a loworder stream and is located in the Gualeguaychú Departament, Entre Ríos, in the Pampean Ecorregion. In order to study the water quality, benthonic macroinvertebrates and physical chemical variables were studied, between March and October 2012. Sixteen orders, 1 suborder and 27 invertebrates families were found. The most abundant families were Cochliopidae, Paleomonidae, Caenidae, and Sphaeriidae. BMWP, IBF, IMRP and IBPamp biotic indices and diversity index of Shannon-Weaver were applied. These showed different results suggesting the need for further studies of water bodies of the Pampas Ecorregion and adjustment of indices for the region. The combined application of different rates indicates that the stream shows signs of seasonal organic pollution associated with land use in the basin.Facultad de Ciencias Naturales y Muse

  • Aplicación de índices de calidad de agua en un arroyo pampeano utilizando macroinvertebrados bentónicos como bioindicadores (Gualeguaychú, Entre Ríos, Argentina)
    Instituto de Limnología "Raúl A. Ringuelet" Facultad de Ciencias Naturales y Museo (UNLP), 2014
    Co-Authors: Crettaz-minaglia, María Celeste, Juaréz, Ricardo Ariel, Aguer Irene, Borro Esteban, Peruzzo Rubén
    Abstract:

    La calidad del agua se puede evaluar a través de un conjunto de variables físicas, químicas y ambientales que caracterizan el cuerpo de agua en estudio. Estas variables, junto con el impacto climático, el régimen hidrológico y el uso de la tierra, determinan la diversidad de los organismos. El arroyo Santa Barbara es un ambiente lótico de bajo orden y está ubicado en el Departamento de Gualeguaychú, Entre Ríos, en la Ecorregión Pampeana. Para estudiar la calidad del agua se estudiaron macroinvertebrados bentónicos y variables fisicoquímicas, entre marzo y octubre de 2012. Se encontraron 16 órdenes, un suborden y 27 familias de invertebrados. Las familias más abundantes fueron Cochliopidae, Paleomonidae, Caenidae y Sphaeriidae. Se aplicaron los índices bióticos de BMW P, IBF, IMRP e IBPamp y el índice de diversidad de Shannon-Weaver. Estos mostraron resultados diferentes que sugieren la necesidad de estudios adicionales de cuerpos de agua de la Ecorregión de Pampas y el ajuste de los índices para la región. La aplicación combinada de diferentes tasas indica que la corriente muestra signos de contaminación orgánica estacional asociada con el uso del suelo en la cuenca.Water quality can be evaluated through a set of physical, chemical and environmental variables that characterize the water body under study. These variables, along with the climate impact, hydrological regime and land use, determine the diversity of organisms. Santa Barbara Stream is a low-order stream and is located in the Gualeguaychú Departament, Entre Ríos, in the Pampean Ecorregion. In order to study the water quality, benthonic macroinvertebrates and physical chemical variables were studied, between March and October 2012. Sixteen orders, 1 suborder and 27 invertebrates families were found. The most abundant families were Cochliopidae, Paleomonidae, Caenidae, and Sphaeriidae. BMWP, IBF, IMRP and IBPamp biotic indices and diversity index of Shannon-Weaver were applied. These showed different results suggesting the need for further studies of water bodies of the Pampas Ecorregion and adjustment of indices for the region. The combined application of different rates indicates that the stream shows signs of seasonal organic pollution associated with land use in the basin

Pedro Jaraseguel - One of the best experts on this subject based on the ideXlab platform.

Alexei V. Korniushin - One of the best experts on this subject based on the ideXlab platform.

  • Anatomy and reproduction of viviparous Pisidium (Parapisidium) reticulatum Kuiper, 1966: Implications for the phylogeny of Sphaeriidae (Mollusca: Bivalvia: Heterodonta)
    Organisms Diversity & Evolution, 2006
    Co-Authors: Alexei V. Korniushin, Matthias Glaubrecht
    Abstract:

    Abstract The pea clams Sphaeriidae represent a major molluscan freshwater radiation with cosmopolitan distribution in all kinds of lotic and lentic habitats. Their phylogenetic relationships are still controversial, with comprehensive taxonomic sampling and examination of morphological characters still challenging. Here, based on rare and rediscovered original material, we study in detail the anatomy and aspects of brood protection of the African Pisidium reticulatum Kuiper, 1966. Representing the monotypic subgenus Parapisidium Kuiper, 1966, this species is characterized by its peculiar combination of shell and anatomical features of potentially high phylogenetic relevance. While similar to other congeners in several anatomical characters (e.g. reduction of inhalant siphon and descending lamella of outer demibranch, simplified structure of intestine coil and nephridium), P. reticulatum differs from other Pisidium species in retaining both pairs of retractor muscles of the inhalant siphon, and particularly in its peculiar mode of brooding. The yolky eggs are relatively large (160–170 μm in diameter) and are incubated in the gill, albeit in the absence of the formation of brood pouches. During later stages of incubation the larvae are surrounded by large cells similar to nourishing cells in other sphaeriids and probably with similar function. This unique combination of reproductive features is hypothesized to represent an intermediate stage between the typical ovoviviparity of Euperidae and euviviparity (i.e. nourishment by the parent animal) as found exclusively in Sphaeriidae, the latter being characterized by the possession of closed brood pouches. Phylogenetic analyses based on a comprehensive set of morphological characters reveal Parapisidium as the most basal lineage within a clade Pisidium. Evaluating the phylogenetic reconstructions based also on available molecular data for Sphaeriidae, we discuss alternative scenaria of (parallel) evolution of brood pouches and viviparity in this group.

  • phylogenetic analysis based on the morphology of viviparous freshwater clams of the family Sphaeriidae mollusca bivalvia veneroida
    Zoologica Scripta, 2002
    Co-Authors: Alexei V. Korniushin, Matthias Glaubrecht
    Abstract:

    The cosmopolitan viviparous bivalves of the family Sphaeriidae (fingernail clams) comprise not only some of the smallest freshwater molluscs, but also an abundant and ecologically important group that often dominates benthic communities of springs, ponds and swamps. The origin from marine ancestors and their subsequent evolution in limnic environments, in particular the development of distinct reproductive modes including complex parental care repertoires, are largely unresolved. This paper presents the results of a phylogenetic analysis of 69 morphological characters from 57 taxa (54 representing sphaeriids throughout the distribution area plus three outgroups). The heuristic search resulted in 753 most-parsimonious trees of length 154 [consistency index (CI) = 0.682, retention index (RI) = 0.906, rescaled consistency index (RC) = 0.618]. Only Pisidium of the three traditionally regarded constituent genera is supported as a monophyletic group; Sphaerium and Musculium in their traditional deliminations are found to be paraphyletic. Instead, the analysis supports a clade comprising all species of Musculium plus Pisidium as suggested by previous morphology-based classifications. However, the shortest tree alternatively supporting a Sphaerium + Musculium clade suggested by molecular data is only one step longer. Some clades that correspond to the subgeneric divisions of the three traditionally recognized sphaeriid genera are supported. Exclusion is suggested of the taxon Euperidae (Eupera and Byssodonta, both with ovo-viviparous species) from the true Sphaeriidae that then comprises all species with eu-viviparous reproductive mode, i.e. brooding and nourishing their embryos in specialized brood pouches in the gills. The implications for the reconstruction of the evolutionary history of Sphaeriidae and the availability of existing taxonomic names for the systematization suggested by the present analysis are discussed.

  • annotated catalogue of type specimens of Sphaeriidae bivalvia heterodonta veneroida in the mollusc collection of the museum fur naturkunde berlin with a review of their current taxonomic status
    Zoosystematics and Evolution, 2001
    Co-Authors: Alexei V. Korniushin, Matthias Glaubrecht
    Abstract:

    The Sphaeriidae, i.e. fingernail, pea or pill clams, comprise the smallest freshwater bivalves as adequately indicated by their naming. The systematics and phylogeny of the family is currently under revision. In connection with this ongoing work published elsewhere we here present an alphabetical catalogue comprising the types of 46 sphaeriid species, subspecies and varieties in the Malacological collection of the Natural History Museum Berlin, each listed by its original and most used current binomina. Several types not known to previous reviewers, e.g. syntypes of Cyclas capense Krauss, 1848 and of two Baikalian species, were found and included. Lectotypes of 9 species are designated herein (including 3 lectotypes selected earlier by Kuiper but not published). Modern views on taxonomy of all species and forms are briefly commented on. The status of the following taxa is changed: Sphaerium asiaticum (v. Martens 1864) is treated as a valid species. Pisidium obtusale var. magnificum Clessin in Westerlund, 1873 is synonymised with P. globulare auct. which is also treated as a distinct species. We suggest that S. naivashaense Preston, 1912 and S. mutandaensis Preston in Dautzenberg & Germain, 1914 are synonyms of S. capense (Krauss 1848) and confirm the synonymy of P. maculatum (Dybowski, 1902) with Lacustrina dilatata (Westerlund. 1897).

  • Moitessier's pea clam Pisidium moitessierianum (Bivalvia, Sphaeriidae): a cryptogenic mollusc in the Great Lakes
    Hydrobiologia, 2000
    Co-Authors: Igor A. Grigorovich, Alexei V. Korniushin, Hugh J. Macisaac
    Abstract:

    Pisidium moitessierianum Paladilhe, 1866, a small pea clam native to Europe, was identified for the first time from the lower Great Lakes basin based on an examination of historical collections of Pisidium performed by V. Sterki in 1894 and 1903 and new material collected during 1997 and 1998. During recent surveys, P. moitessierianum individuals were found in the St. Clair River delta, Lake St. Clair and western Lake Erie, but were not detected in the Detroit River or western Lake Ontario. Pisidium moitessierianum was collected on sand, silty sand and mud substrata from water depths ranging between 0.6 and 5.4 m. Populations occurred at an average density of 51 ind. m−2 and included juveniles and adults. All individuals were less than 2.0 mm in length. We examined the structure of the umbos and hinge, surface sculpture and shape of the shell, and the anatomy of gills, mantle and nephridia in populations from the lower Great Lakes and Ukrainian inland basins (Dnieper River and Lake Beloye). The results indicated that the Great Lakes' pea clams match European specimens of P. moitessierianum in these conchological and anatomical characteristics. As with other nonindigenous sphaeriids in the Great Lakes, P. moitessierianum was likely introduced through shipping activities into the Great Lakes, possibly as early as the 1890s.

  • Anatomy of New Zealand species of the family Sphaeriidae (Bivalvia, Eulamellibranchia)
    Molluscan Research, 1999
    Co-Authors: Alexei V. Korniushin, Nikolai Glushchenko
    Abstract:

    Abstract Mantle edge, gills, brood pouches and nephridia are described in Musculium novaezelandiae (Deshayes 1854), Pisidium hodgkini (Suter, 1905) and P. novaezelandiae Prime, 1862. Affinity of the first species to the subgenus Sphaerinova Iredale and placement of the second one in the subgenus Afropisidium Kuiper is confirmed by anatomical characters. The problem of identity of P. novaezelandiae and P. casertanum (Poli, 1791) is discussed.