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12 resultados encontrados para: TEMA: Ostracoda
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1.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
Integrative taxonomy of freshwater ostracodes (Crustacea: Ostracoda) of the Yucatán Peninsula, implications for paleoenvironmental reconstructions in the northern Neotropical region
Macario González, Laura (autor) ; Cohuo, Sergio (autor) ; Elías Gutiérrez, Manuel (autor) ; Vences, Miguel (autor) ; Pérez, Liseth (autor) ; Schwalb, Antje (autor) ;
Contenido en: Zoologischer Anzeiger Vol. 275 (July 2018), p. 20-36 ISSN: 0044-5231
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

A three-step integrative taxonomy approach combining molecular, morphological and ecological methods was successfully used to delimit species boundaries within three freshwater ostracode taxa of the Yucatán Peninsula (Mexico): Darwinulidae, Cypretta and Cypridopsis. These species groups were selected because they are well-suited paleobioindicators for late Pleistocene-early Holocene climatic reconstructions in the region, but their high inter-population morphological variability in recent communities represents a challenge for accurate transfer of information to fossil assemblages. As a first step, we analyzed the congruence of two genes of different inheritance, the mitochondrial COI (cytochrome c-oxidase subunit 1), and the nuclear 18S rDNA (small-subunit rDNA). Second, we tested the lineages discriminated for concordant differentiation in morphology, using morphometry of the carapace and typological analysis of the appendages. The third step assessed the association of occurrences and abundances of lineages to environmental variables. The integration of these methods revealed six hidden species within clades previously considered as a single widely distributed nominal species. Of these, Cypretta elongata sp. nov. and Alicenula yucatanensis sp. nov. are herein formally named and described given their morphological distinctness.

Three species of Cypridopsis: Cypridopsis sp. [Ca1 ECO-CH-Z-09396], Cypridopsis sp. [Ca2 ECO-CH-Z-09398], Cypridopsis sp. [Ca3 ECO-CH-Z-09401] and a species that may represent a new genus, Cyprididae sp. [Ca1 ECO-CH-Z-09402], are allocated to a confirmed candidate full species status. Cypretta maya and Cypretta sp., considered a priori as separate species, are recognized as a single species with phenotypic plasticity, attributed to its broad ecological tolerances. For paleoenvironmental reconstructions these results have relevance because the particular carapace morphology of the new species can be correlated with specific ecological traits, thus constituting a potential tool for refining interpretations of fossil assemblages.


2.
Artículo
*Solicítelo con su bibliotecario/a
A new freshwater ostracod genus from the northern Neotropical region and its phylogenetic position in the family Cyprididae (Podocopida)
Yoo, Hyunsu ; Cohuo Durán, Sergio (coaut.) ; Macario González, Laura (coaut.) ; Karanovic, Ivana (coaut.) ;
Contenido en: Zoologischer Anzeiger - A Journal of Comparative Zoology Vol. 266 (January 2017), p. 196–215 ISSN: 0044-5231
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

Manuelcypris n. gen., along with two species M. chetumalensis n. sp. and M. tabascena n. sp., are described from Southern Mexico. Another three species are transferred into the new genus: M. cisternina (Furtos, 1936) comb. nov., known from the Yucatan Peninsula, was originally described in the genus Eucypris Vávra, 1891, while M. punctata (Keyser, 1975) comb. nov., from Florida, and M. antillensis (Broodbakker, 1982) comb. nov., from the West Indies, were originally described in the genus Heterocypris Claus, 1892. The latter two new combinations are based only on the literature data, while for M. cisternina we examined its type material. The new genus is attributed to Cyprinotinae, but with an isolated position based on the absence of any seta on the basal segment of the walking leg and the reduced chaetotaxy of the fifth leg. The validity of this genus is confirmed with molecular markers, 18S rDNA and 28S rDNA which were used in the phylogenetic reconstruction along with several newly obtained sequences and others downloaded from the GenBank belonging to closely related taxa. Two methods, Maximum Parsimony and Maximum Likelihood, used in the analysis support the new genus with 100 bootstrap values. We also provide a taxonomic key for the five representatives of the new genus.


3.
- Artículo con arbitraje
*En hemeroteca, SIBE-San Cristóbal
On Limnocytherina axalapasco, a new freshwater ostracod (Podocopida: Limnocytheridae) from Mexican crater lakes
Cohuo Durán, Sergio ; Pérez, Liseth (coaut.) ; Karanovic, Ivana (coaut.) ;
Contenido en: Revista de Biología Tropical Vol. 62, n. 1 (marzo 2014), p. 15-32 ISSN: 0034-7744
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
53388-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-San Cristóbal
PDF
Resumen en: Español | Inglés |
Resumen en español

Limnocytherina es un género conformado por 12 especies; su distribución en el continente Americano se conoce exclusivamente en el norte (zona neártica), pero se sabe poco de su distribución en México (zona de transición) y Centro América (zona neotropical). Luego de diferentes campañas de muestreo en tres lagos cráter de la región de los Axalapascos en la zona centroeste de México, durante 2008, 2009 y 2011, se encontró a Limnocytherina axalapasco, una nueva especie, que mostró variabilidad intraespecífica entre poblaciones. Un total de 10 muestras de sedimentos (8 del litoral, 2 del punto más profundo) fueron recolectadas de los lagos Alchichica, La Preciosa y Quechulac. L. axalapasco está estrechamente relacionada con dos especies norteamericanas: L. posterolimba y L. itasca, así como con una especie centroamericana Limnocytherina royi comb. nov. Con la inclusión de L. axalapasco y L. royi al género, la distribución de Limnocytherina se extiende hasta Centro América.

Los cuatro caracteres distintivos más importantes de esta nueva especie son: 1) superficie y márgenes de valvas cubiertos por pequeñas proyecciones parecidas a espinas; 2) La mayoría de las setas de A1 tienen una setula muy desarrollada en la zona distal, con apariencia de estar bifurcadas; 3) El ramo superior del hemipene es alargado y por mucho sobrepasa los márgenes dorsal/distal; el lóbulo distal es corto y triangular, mientras que el proceso prensil es prominente, orientado externamente y sobrepasa la longitud del lóbulo distal; 4) el UR está moderadamente desarrollado con la seta f3 alargada y las setas f1 y f2 cortas. Para esta especie se describe también su hábitat, preferencias ecológicas y desarrollo larvario. L. axalapasco prefiere aguas alcalinas dominadas por Cl- o HCO3 - y Na+ o Mg2+, temperaturas entre 19.1 a 20.3°C y concentraciones de oxígeno disuelto de 5 a 6.5 mg/L. Esta especie es más abundante en las zonas profundas (~64m) del lago salino Alchichica, donde la conductividad del agua es de hasta 2 250μS/cm. Arenas con bajos porcentajes de limo parecen ser el sustrato preferido. Aunado a la descripción de L. axalapasco, proveemos información adicional para los hemipenes de L. itasca, L. royi y L. sanctipatricii, y discutimos el tipo de hemipene en Limnocytherina.

Resumen en inglés

Limnocytherina is a genus conformed by 12 species; its distribution in the American continent is known to be exclusively on the North (neartics), but little is reported about its distribution from Mexico (transition zone) and Central America (Neotropics). Different sampling campaigns were undertaken in three crater lakes from the Axalapascos region in east-central Mexico, during 2008, 2009 and 2011. As a product of these campaings, the new species of Limnocytherina axalapasco was found, which displays some intraspecific variability among populations. In this study, we described the taxonomy, the habitat, the ecological preferences and the larval development of this new species. A total of 10 sediment samples (8 littoral, 2 deepest point) were collected from lakes Alchichica, La Preciosa and Quechulac. We found that L. axalapasco is closely related to two North American species: L. posterolimba and L. itasca as well as one Central American species L. royi comb. nov. With the inclusion of L. axalapasco and L. royi to the genus, the distribution of Limnocytherina is extended to Central America.

The four most important distinguishing characters of this new species are: 1) valve surface and margins covered with small, spine-like projections; 2) most of the A1 setae with a highly developed setule at distal part, producing a bifurcate appearance; 3) the upper ramus on the hemipenis is elongated, and by far overpasses dorsal/distal margins, distal lobe is triangular and short, while the hook-like process is prominent, outward orientated, and overpassing the tip of the distal lobe; 4) the UR is moderately developed with seta f3 elongated and setae f1 and f2 short. Considering its ecological characteristics and larval development, L. axalapasco was preferably found in alkaline waters dominated by Cl- or HCO3- and Na+ or Mg2+, temperatures ranging between 19.1 to 20.3°C, and dissolved oxygen concentrations from 5 to 6.5mg/L. This species was abundant in deeper (~64m) areas of the saline Alchichica lake, where surface water displayed conductivity values of up to 2 250μS/cm, and the sand with low percentage of silt resulted the preferred substrate. Along with the description of L. axalapasco, we provide additional information on the hemipenis of L. itasca, L. royi and L. sanctipatricii, and we discuss on the Limnocytherina-type of hemipenis.


4.
- Artículo con arbitraje
*En hemeroteca, SIBE-Chetumal, SIBE-San Cristóbal
Bioindicators of climate and trophic state in lowland and highland aquatic ecosystems of the Northern Neotropics
Pérez, Liseth ; Lorenschat, Julia (coaut.) ; Massaferro, Julieta (coaut.) ; Pailles, Christine (coaut.) ; Sylvestre, Florence (coaut.) ; Hollwedel, Werner (coaut.) ; Brandorff, Gerd Oltmann (coaut.) ; Brenner, Mark (coaut.) ; Islebe, Gerald A. (coaut.) ; Lozano, María del Socorro (coaut.) ; Scharf, Burkhard (coaut.) ; Schwalb, Antje (coaut.) ;
Contenido en: Revista de Biología Tropical Vol. 61, no. 2 (June 2013), p. 603-644 ISSN: 0034-7744
Bibliotecas: Chetumal , San Cristóbal
Cerrar
SIBE Chetumal
35622-30 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
35622-20 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Chetumal, SIBE-San Cristóbal
PDF
Resumen en: Español | Inglés |
Resumen en español

Los quironómidos, diatomeas y microcrustaceos que habitan ecosistemas acuáticos en el norte de los Neotrópicos son abundantes y diversos. Algunas especies son altamente sensibles a cambios en la composición química del agua y en el estado trófico. Este estudio se realizó como el primer paso para desarrollar funciones de transferencia para inferir condiciones ambientales en el norte de las tierras bajas de los Neotrópicos. Es por esto que las abundancias de especies bioindicadoras se relacionaron con múltiples variables ambientales con el fin de explotar al máximo su uso como indicadores ambientales y paleoambientales. Recolectamos y analizamos muestras de agua y de sedimento superficial de 63 cuerpos de agua, ubicados a lo largo de un gradiente trófico y de gradientes marcados de altitud (~0-1 560m.s.n.m.) y de precipitación (~400-3 200mm/año), desde el NO de la Península de Yucatán (México) hasta el sur de Guatemala. Relacionamos 14 variables limnológicas con las abundancias relativas de 282 especies de diatomeas, 66 morfoespecies de quironómidos, 51 especies de cladóceros, 29 especies de ostrácodos no-marinos y seis especies de agua dulce de cladóceros calanoides. La estadística multivariada indicó que el bicarbonato es el principal determinante de la distribución de quironómidos y copépodos.

El estado trófico es el segundo factor más importante en determinar la distribución de quironómidos. La conductividad, que está relacionada con el gradiente de precipitación e influencia marina en la Península de Yucatán, es la principal variable en influir las comunidades de diatomeas, ostrácodos y cladóceros. Las diatomeas, quironómidos y cladóceros (H=2.4-2.6) presentaron diversidades más altas que los ostrácodos y copépodos (H=0.7-1.8). La riqueza de especies y la diversidad fueron más altas en las elevaciones bajas (<450m.s.n.m) que en elevaciones altas en Guatemala. La distribución y diversidad de bioindicadores es afectada por múltiples factores incluyendo la altitud, precipitación, composición química del agua, estado trófico y el impacto humano.

Resumen en inglés

Chironomids, diatoms and microcrustaceans that inhabit aquatic ecosystems of the Northern Neotropics are abundant and diverse. Some species are highly sensitive to changes in water chemical composition and trophic state. This study was undertaken as a first step in developing transfer functions to infer past environmental conditions in the Northern lowland Neotropics. Bioindicator species abundances were related to multiple environmental variables to exploit their use as environmental and paleoenvironmental indicators. We collected and analyzed water and surface sediment samples from 63 waterbodies located along a broad trophic state gradient and steep gradients of altitude (~0-1 560m.a.s.l.) and precipitation (~400-3 200mm/y), from NW Yucatán Peninsula (Mexico) to southern Guatemala. We related 14 limnological variables to relative abundances of 282 diatom species, 66 chironomid morphospecies, 51 species of cladocerans, 29 non-marine ostracode species and six freshwater calanoid copepods. Multivariate statistics indicated that bicarbonate is the strongest driver of chironomid and copepod distribution. Trophic state is the second most important factor that determines chironomid distribution. Conductivity, which is related to the precipitation gradient and marine influence on the Yucatán Peninsula, is the main variable that shapes diatom, ostracode and cladoceran communities. Diatoms, chironomids and cladocerans displayed higher diversities (H=2.4-2.6) than ostracodes and copepods (H=0.7- 1.8). Species richness and diversity were greater at lower elevations (<450m.a.s.l.) than at higher elevations in Guatemala. Distribution and diversity of bioindicators are influenced by multiple factors including altitude, precipitation, water chemistry, trophic state and human impact.


5.
- Artículo con arbitraje
On three new species of Cypretta Vávra, 1895 (Crustacea: Ostracoda) from the Yucatan Peninsula, Mexico
Cohuo Durán, Sergio ; Elías Gutiérrez, Manuel (coaut.) ; Karanovic, Ivana (coaut.) ;
Contenido en: Zootaxa Vol. 3636, no. 4 (2013), p. 501–524 ISSN: 1175-5326
Resumen en: Inglés |
Resumen en inglés

Three new species of the genus Cypretta Vávra, 1985 are described from Southern Mexico, representing the first record of the genus in the country. Cypretta campechensis n. sp. is closely related to Florida and North Carolina species such as C. nigra Furtos, 1936, C. brevisaepta Furtos, 1934 and C. bilicis Furtos, 1936. Cypretta spinosa n. sp. is related to the North and South American species C. intonsa Furtos, 1936 and C. vivacis Würdig & Pinto, 1993, but also to some Australian and South-East Asian Islands ones, such as C. obfuscata Victor & Fernando, 1981 and C. raciborskii (Grochmalicki, 1915). The last species described herein, Cypretta maya n. sp., is closely related to the South-East Asia islands, Australian and north Indian species, in particular to C. hirsuta Henry, 1923, C. longidactyla Victor & Fernando, 1981, and C. patialensis Battish, 1982.


6.
Artículo
Biocenotic characteristics of some Yucatan lentic water bodies based on invertebrate remains in sediments
Smirnov, Nicolai N. ; Elías Gutiérrez, Manuel (coaut.) ;
Contenido en: Inland Water Biology Vol. 4, no. 2 (Apr. 2011), p. 211-217 ISSN: 1995-0829
Resumen en: Inglés |
Resumen en inglés

The Yucatan Peninsula is a karstic environment with almost no permanent surface water flows. All freshwater lentic systems here are supported by underground water. We examined sediments, obtained with an Eckman dredge, from 25 different types of water bodies (sinkholes or cenotes, lagoons, and wetlands), to investigate their biocenotic characteristics. All systems showed differences in their zoocenoses, ostracods being the dominant group in most. Cladocera were scarce in the sediments, represented by only eight genera. It can be partially related to the near absence of a littoral zone in cenotes, due to vertical walls, and the lack of submersed vegetation. In spite of their importance, relatively little work has been done on ostracods from this region of the world.


7.
- Tesis
Caracterización y distribución de ostrácodos en sistemas dulceacuícolas de la Península de Yucatán / Sergio Cohuo Duran
Cohuo Duran, Sergio ;
Chetumal, Quintana Roo, México : Instituto Tecnológico de Chetumal , 2010
Clasificación: TE/592.097267 / C6
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
ECO030007293 (Disponible)
Disponibles para prestamo: 1
Resumen en: Español |
Resumen en español

En México el estudio sistemático de los ostrácodos ha sido tradicionalmente escaso y en la península de Yucatán solo se ha realizado un estudio desde 1936 donde se encontraron 13 nuevas especies. Con el objetivo de revisar la ostrácodofauna actual de la península de Yucatán se muestrearon 49 sistemas dulceacuicolas, encontrándose 25 especies, las cuales se caracterizaron y describieron. Del total de especies encontradas 10 se identificaron a nivel de especie, 4 a nivel de familia y se encontró un complejo de especies Cypridopsis vidua. Se espera que algunas de las especies encontradas sean nuevas para la ciencia y en un primer reconocimiento se consideran que las especies, Cypretta cf. intonsa, Cypretta, Cypridacea 1, Cypria 1 son nuevas especies. Adicionalmente de comprobó la utilidad de los códigos de barra de la vida, como herramienta en la identificación taxonómica de los ostrácodos, donde se obtuvieron 11 secuencias (primeras secuencias en México para este grupo) pertenecientes a 4 especies que coincidieron con el análisis morfológico, sugiriéndose que es un método aplicable a la identificación taxonómica de estos organismos. Con los resultados obtenidos de este método se comparó la ostracodofauna de Canadá y la Península de Yucatán encontrándose diferencias totales, asegurando que la composición de especies es diferente en la región Neártica y Neotropical.


8.
Artículo
*En hemeroteca, SIBE-Chetumal
Distribution, diversity and ecology of modern freshwater ostracodes (Crustacea), and hydrochemical characteristics of Lago Petén Itzá, Guatemala
Pérez, Liseth ; Lorenschat, Julia (coaut.) ; Bugja, Rita (coaut.) ;
Contenido en: Journal of Limnology Vol. 69, no. 1 (2010), p. 146-159 ISSN: 1129-5767
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
48860-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Chetumal
PDF
Resumen en: Inglés |
Resumen en inglés

We analyzed modern ostracode species assemblages and water column physico-chemical characteristics in Lago Péten Itzá, Guatemala. Lake waters are dominated by sulfate, bicarbonate, calcium and magnesium and display a total ion concentration of ~11 meq L-1. Eleven extant ostracode species were identified. We found higher abundances of living ostracodes, as well as relatively higher species richness (eight species) and biodiversity (H of 1.6) between the littoral zone and a water depth of 20 m. At water depths >40 m, these variables all decreased. The thermocline is located at a water depth of ~20-40 m. Cluster analysis revealed three water depth ranges in the lake of importance to ostracode distribution: 1) littoral zone (0.1-3 m), 2) water depths from the base of the littoral zone to the base of the thermocline (3-40 m), and 3) water depths below the thermocline (40-160 m). The assemblage "Darwinula-Heterocypris-Pseudocandona-Strandesia" is characteristic of waters <15 m. The "Cypridopsis-Cytheridella-Limnocythere" assemblage characterizes waters <40 m and "Physocypria" indicates waters >40 m. Ostracode taxa from Lago Petén Itzá show specific ecological preferences related to water depth and associated physico-chemical characteristics, thus illustrating the potential of ostracodes as indicators of lake level changes and hydrodynamics.


9.
Artículo
*En hemeroteca, SIBE-San Cristóbal
Extant freshwater ostracodes (Crustacea: Ostracoda) from Lago Petén Itzá, Guatemala
Pérez, Liseth ; Lorenschat, Julia (coaut.) ; Brenner, Mark (coaut.) ; Scharf, Burkhard (coaut.) ; Schwalb, Antje (coaut.) ;
Contenido en: Revista de Biología Tropical Vol. 58, no. 3 (setiembre 2010), p. 871-907 ISSN: 0034-7744
Bibliotecas: Chetumal , San Cristóbal
Cerrar
SIBE Chetumal
50233-20 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
50233-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-San Cristóbal
PDF
Resumen en: Inglés |
Resumen en inglés

Ostracode taxonomy has been of great interest because of their possible use as indicator species in climate and ecosystem changes. In Central and South America, few studies have been carried out and this study includes a contribution to the group. Eleven ostracode species were collected in Lago Petén Itzá (~100km2), the second largest lowland lake in Guatemala, and from its inflow tributary, Río Ixlú in November 2005 and February 2008. Twenty-seven surface sediment samples were retrieved at water depths from the littoral zone to the lake’s maximum depth (>160m). Hard and soft parts of ostracodes were analyzed, and each ostracode species was described for taxonomy, size, ecology, biology and geographic distribution. Species recorded include: Candonocypris serratomarginata?, Cypretta brevisaepta?, Cypridopsis okeechobei, Cytheridella ilosvayi, Darwinula stevensoni, Heterocypris punctata, Limnocythere opesta, Physocypria globula, Pseudocandona sp., Stenocypris major and Strandesia intrepida. Most of the species have a neotropical distribution, two are distributed world-wide (D. stevensoni and S. major), and C. okeechobei and P. globula display nearctic and neotropical distributions. We present new records of C. brevisaepta?, C. serratomarginata?, S. major, and S. intrepida in Guatemala. Physocypria globula was misidentified previously in Lago Petén Itzá as Cypria petenensis, Pseudocandona sp. was misidentified as Candona sp., and C. okeechobei was identified in the past as C. vidua. Limnocythere opesta is the only endemic species of the Petén Lake District, Guatemala.

The most abundant and widely distributed species in the lake are P. globula, C. okeechobei, and Pseudocandona sp. Species restricted to the littoral zones and water depths <15m are C. brevisaepta?, D. stevensoni, H. punctata, and S. intrepida. Limnocythere opesta, C. ilosvayi, C. okeechobei, and Pseudocandona sp. are distributed from the littoral zone to a depth of 40m. Species collected only in the Ixlú tributary and in a littoral zone on the west side of the lake were C. serratomarginata? and S. major. During November, live adult L. opesta and C. okeechobei were abundant, but no C. brevisaepta? or C. serratomarginata? adults were found. Adult specimens of C. ilosvayi were more abundant in February. In general, ostracodes collected were smaller than those reported in the literature. An accurate taxonomy will improve the use of ostracode fossil assemblages in long sediment cores when reconstructing past climatic and environmental changes in the northern lowland Neotropics.