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11 resultados encontrados para: TEMA: Astyanax
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1.
Artículo
*Solicítelo con su bibliotecario/a
A geographical cline in craniofacial morphology across populations of Mesoamerican lake-dwelling fishes
Powers, Amanda K. (autora) ; Garita Alvarado, Carlos A. (autor) ; Rodiles Hernández, María del Rocío (autora) (1956-) ; Berning, Daniel J. (autor) ; Gross, Joshua B. (autor) ; Ornelas García, Claudia Patricia (autora) ;
Disponible en línea
Contenido en: Journal of Experimental Zoology. Part A: Ecological and Integrative Physiology Vol. 333, no 3 (March 2020), p. 171-180 ISSN: 2471-5646
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Resumen en: Inglés |
Resumen en inglés

Together, the complex geological history and climatic diversity of Mesoamerica create a rich source of biodiversity from which evolutionary processes can be studied. Here, we discuss highly divergent morphs of lake‐dwelling fishes distributed across Mexico and Central America, originally recognized as members of different genera (Astyanax and “Bramocharax”). Recent phylogenetic studies, however, suggest these morphs group within the same genus and readily hybridize. Despite genetic similarities, Bramocharax morphs exhibit stark differences in cranial shape and dentition. We investigated the evolution of several cranial traits that vary across morphs collected from four lakes in Mexico and Nicaragua and discovered an ecomorphological cline from northern to southern lakes. Northern populations of sympatric morphs exhibit a similar cranial shape and tooth morphology. Southern populations of Bramocharax morphs, however, showed a larger disparity in maxillary teeth, length and frequency of unicuspid teeth, an elongated snout, and a streamlined cranium compared to Astyanax morphs. This divergence of craniofacial morphology likely evolved in association with differences in trophic niches. We discuss the morphological differences across the four lake systems in terms of geological history and trophic dynamics. In summary, our study suggests that Bramocharax morphs are likely locally adapted members derived from independent Astyanax lineages, highlighting an interesting parallel evolutionary pattern within the Astyanax genus.


2.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

Assessments of trophic diversity are critical for evaluating ecological integrity of habitats, but interpretations of such assessments require an understanding of variation across natural environmental gradients. This can be problematic when comparing structure of assemblages in under-studied regions or habitats, such as watersheds in dry tropical forests. Here,we compared assemblage-wide trophic metrics and intraspecific variation for a subset of consumer traits across rivers and among different ecosystem types within the Grijalva and Usumacinta River basins of Mexico. The two rivers differ with respect to flow-regime alteration and climate: the Grijalva River has been hydrologically altered by a series of dams and has wet and dry tropical forests in its watershed, whereas the Usumacinta River remains unimpounded with a watershed dominated by tropical wet forest. Use of allochthonous resourceswas pervasive in Usumacinta basin tributaries,with stable isotope signatures suggesting that many fishes directly consumed riparian plants and detritus. In contrast, fish assemblages inGrijalva basin tributaries were supported by higher proportions of in-stream production. Food-chain length was highest in a Grijalva River reservoir fish assemblage, although trophic diversity was lowin the impounded systemcompared to the mainstem Usumacinta River, where fishes consumed the broadest variety of food resources. We also observed differences in trophic ecology and body nutrient content within taxa across habitat types and basins. The differences we observed suggest that even in relatively intact watersheds, expectations for trophic structure in tropical streams should be adjusted based on factors such as discharge, climate, and riparian forest cover.


3.
- Artículo con arbitraje
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A revision of Astyanax (Characiformes: Characidae) in Central and North America, with the description of nine new species
Schmitter Soto, Juan Jacobo ;
Contenido en: Journal of Natural History Vol. 51, no. 4 (July 2017), p. 1-94 ISSN: 1536-2442
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Resumen en: Inglés |
Resumen en inglés

Since the restriction of Astyanax fasciatus to Brazil, most authors have assigned Central American and southern Mexican forms of Astyanax to A. aeneus. However, molecular studies support the hypothesis that more than one taxon is involved. With the aim of clarifying the number and status of species hidden behind the name ‘A. aeneus’, this revision comprises 80 populations of Astyanax (and ‘Bramocharax’) from Panama to Texas, with comparative material from South America, based on morphological characters (mostly osteological). Astyanax aeneus is hereby restricted to the Pacific slope, from Río Papagayo, Guerrero, to Honduras. Several species are resurrected from synonymy or redescribed: A. altior (restricted to north-western Yucatán), A. argentatus (Texas and northern Mexico), A. belizianus (central-southern Belize, Izabal, Caribbean Honduras), A. brevimanus (upper Usumacinta and Grijalva, Chiapas, Quiché, Alta Verapaz), A. finitimus (Veracruz, Tabasco, northern Chiapas), A. mexicanus (restricted to Colima and the Balsas River basin), A. nicaraguensis (Caribbean Nicaragua to Sixaola, Panama), A. orstedii (south-eastern Nicaragua, Costa Rica and westernmost Panama), A. panamensis (Pacific Panama), and A. petenensis (Campeche, Petén). Nine species are newly described: A. acatlanensis sp. nov. (inland Oaxaca and Puebla), A. bacalarensis sp. nov. (Quintana Roo, northern Belize, Petén), A. cubilhuitz sp. nov. (Alta Verapaz), A. macal sp. nov. (Maya Mountains, Belize), A. ocotal sp. nov. (Lake Ocotal, highland Chiapas), A. rioverde sp. nov. (San Luis Potosí), A. salvatoris sp. nov. (Tamazulapan, Oaxaca), A. tamiahua sp. nov. (northern Veracruz) and A. tehuacanensis sp. nov. (Papaloapan, Oaxaca). Others were already recognised as different from A. aeneus, among these A. cocibolca and A. nasutus, as well as species included before in the genus Bramocharax.


4.
- Artículo con arbitraje
*Solicítelo con su bibliotecario/a
A phylogeny of Astyanax (Characiformes: Characidae) in Central and North America
Schmitter Soto, Juan Jacobo ;
Contenido en: Zootaxa Vol. 4109, no.2 (May 2016), p. 101-130 ISSN: 1175-5334
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Resumen en: Inglés |
Resumen en inglés

A phylogeny is presented for 34 species of Astyanax , 27 of them once included within A. aeneus or A. fasciatus in Central America and Mexico, based on 52 morphological characters (mostly osteological, but also pigmentation and meristics), with three outgroups. Monophyly is not supported for A. aeneus s. lat., as Brazilian species such as A. fasciatus s. str. and others occur also within that clade. There were only five resolved clades, three of them including both Brazilian and Central American species, one purely Nicaraguan, and one for central-northern Mexico and Texas. Coincidence with previous cladistic hypotheses is only partial. The genus Bramocharax Gill is not recovered, and thus confirmed as a synonym of Astyanax Baird & Girard . The findings point at a more complex biogeographic history of the region than usually recognized.


5.
Artículo
*En hemeroteca, SIBE-San Cristóbal
Reproductive traits and population structure of Astyanax aeneus (Characiformes:Characidae) from a subtropical river in Mexico
Trujillo Jiménez, Patricia ; Sedeño Díaz, Jacinto Elías (coaut.) ; Camargo, Julio A. (coaut.) ;
Contenido en: Revista de Biología Tropical Vol. 61, no. 2 (junio 2013), p. 769-786 ISSN: 0034-7744
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
53016-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-San Cristóbal
PDF
Resumen en: Español | Inglés |
Resumen en español

El Río Champotón es un área de desconocimiento científico dentro del hotspot de Mesoamérica en el sureste de México. Las características reproductivas y la estructura de la población de Astyanax aeneus fueron analizadas a lo largo de un gradiente ambiental en la porción dulceacuícola del río. Se estudiaron tres sitios: en la parte alta del río San Juan Carpizo, en la porción media San Antonio del Río y río abajo en Ulumal, en cinco períodos entre 2007 y 2008. Se registraron diversos factores ambientales en cada sitio de estudio. Los ejemplares de A. aeneus se recolectaron con redes de arrastre de 5 y 10m de largo por 5m de profundidad (0.03m malla) y atarraya (con luz de malla de 0.05m). Las redes fueron lanzadas durante 1 hora en cada sitio. En cada visita se recolectaron un promedio de 80 especímenes en cada sitio de estudio que se preservaron en formaldehído al 10% para su posterior análisis. Para cada sitio de estudio se analizó la estructura de la población por talla, con base en las frecuencias relativas de las clases de longitud estándar. Se determinó la relación peso-talla, se identificaron las etapas del desarrollo gonadal, la época reproductiva, el tamaño de primera madurez sexual, la fecundidad absoluta y relativa, la proporción de sexos y los índices somáticos (gonadosomático, hepatosomático y el factor de condición de Fulton). Se obtuvieron siete clases de talla en la parte alta y media del río y nueve río abajo, con un patrón de distribución estacional y espacial en las frecuencias de clase de tallas. La talla de primera madurez fue de 45.7mm en hembras y 40.8mm en machos. La máxima fecundidad absoluta se registró río abajo y se correlacionó positivamente con el peso corporal y la longitud estándar.

La proporción de sexos (1.8:1 machos: hembras) difiere significativamente de los valores esperados (1:1). Los resultados del índice gonadosomático (IGS) indican que el período reproductivo en el Río Champotón es en julio, durante la temporada húmeda y cálida. El índice hepatosomático se correlacionó negativamente con el IGS, evidenciando la transferencia de energía desde el hígado hacia la producción de gametos. Esta estrategia permitió que A. aeneus mantuviera una condición robusta durante el periodo de estudio con pequeños cambios en el factor de condición. Nuestros resultados indican que A. aeneus en el río Champotón, a diferencia de otras especies del mismo género y de la misma talla en ríos de Sudamérica, presenta una maduración sexual precoz, una temporada reproductiva corta con elevados valores del IGS, y una elevada fecundidad, lo que compensa la temporada de reproducción corta. También se percibe una tendencia a la segregación espacial y temporal: los reproductores se congregan aguas abajo y los juveniles prefieren las partes más altas. Este patrón permite a A. aeneus tener éxito en un río con una alta frecuencia de huracanes.

Resumen en inglés

Champotón River is an unknown area within the Mesoamerican hotspot in Southestern México. Reproductive traits and population structure of Astyanax aeneus were analyzed along an environmental gradient of the upper, middle and lower sections of the river, where diverse environmental factors were recorded. For this, nets were cast for 1h at each site and A. aeneus were collected from all sections with sweep nets (5 and 10m long by 5m deep, 0.03m mesh size) and a casting net (0.05m mesh size). At each study site and campaign, a total of 80 specimens (in average) were collected and were fixed in 10% formaldehyde for further analysis. Population structure by size was analyzed for each study site, based on the relative frequencies by standard length classes. The length-weight relationship was determined, and the identification of gonadal developmental stages, reproductive period, size at first sexual maturity, relative fecundity, sex ratio and somatic indexes (gonadosomatic, hepatosomatic and Fulton’s condition factor) were also assessed. Seven size classes were found in the upper and middle sections, and nine downstream, with seasonal and spatial pattern in size-class frequency distribution. Size at first maturity was 45.7mm for females and 40.8mm for males.

The maximum relative fecundity was recorded at the downstream site and was positively correlated with body weight and standard length. Sex ratio (1.8:1 males: females) differed significantly from expected values (1:1). Gonadosomatic index scores indicated that the reproductive period of this species in the Champotón River was from April to July, during the warm and wet season. Hepatosomatic index was negatively correlated with the Gonadosomatic index, evidencing transfer of energy from the liver towards gamete production. This strategy enabled A. aeneus to maintain robustness during the study period with tiny changes in condition factor. A. aeneus in the Champotón River, as opposed to South American river congeneric species of similar size, shows early sexual maturity, a short reproductive period with high gonadosomatic index values, and high fecundity, a trade-off for the short reproductive period. Spatio-temporal segregation was evident: breeders congregate downstream, while juveniles prefer the upper reaches. This pattern allows A. aenus to be successful in a river with high frequency of hurricanes.


6.
- Artículo con arbitraje
*En hemeroteca, SIBE-Chetumal
Astyanax armandoi, a junior synonym of Astyanax aeneus (Teleostei: Characidae)
Schmitter Soto, Juan Jacobo ; Valdéz Moreno, Martha (coaut.) ; Rodiles Hernández, María del Rocío (coaut.) (1956-) ; González Díaz, Alfonso Ángel (coaut.) ;
Contenido en: Copeia Vol. 2008, no. 2 (June 2008), p. 409-413 ISSN: 0045-8511
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
26395-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Chetumal
Resumen en español

Astyanax armandoi Lozano-Vilano and Contreras-Balderas, 1990, un carácido descrito como endémico de un pequeño arroyo en el sur de México, se considera en este trabajo como sinónimo de A. aeneus (Günther, 1860), especie de amplia distribución en el norte de Centroamérica. La diagnosis de A. armandoi se basa en su labio inferior expandido, junto con un conjunto de caracteres osteológicos. La expansión labial se ha observado también en otras poblaciones de Astyanax (en Campeche y en Chiapas, México) y se trata de un ecofenotipo, una adaptación a condiciones de hipoxia. Los caracteres osteológicos, merísticos, y morfométricos de A. armandoi son compatibles con la notable variación intra- e interpoblacional de A. aeneus. La localidad tipo ha sido visitada repetidamente durante la última década sin que se hayan encontrado más especímenes identificables como A. armandoi, sólo el típico A. aeneus. Esta conclusión implica que A. armandoi debe borrarse de la Norma Oficial Mexicana (NOM-059-SEMARNAT-2001) y de listas similares de especies en peligro.

Resumen en inglés

Astyanax armandoi Lozano-Vilano and Contreras-Balderas, 1990, a characid described as endemic to a small stream in southern Mexico, is hereby synonymized with A. aeneus (Günther, 1860), a species widespread in northern Central America. Astyanax armandoi was diagnosed by its expanded lower lip, in combination with a suite of osteological characters. The labial expansion has been shown in other Astyanax populations (in Campeche and Chiapas, Mexico) to be an ecophenotype, an adaptation to hypoxia. The osteological, meristic, and morphometric characters of A. armandoi are compatible with the remarkable intra- and interpopulational variation of A. aeneus. The type locality has been repeatedly visited in the last decade; no further specimens identifiable as A. armandoi have been found, only typical A. aeneus. This conclusion implies that A. armandoi should be taken off the Mexican list of endangered species (NOM-059-SEMARNAT-2001) and similar lists.


7.
- Artículo con arbitraje
Skull osteology of the characid fish astyanax mexicanus (teleostei: characidae)
Valdéz Moreno, Martha ; Contreras Balderas, Salvador (coaut.) ;
Clasificación: AR/597.0972 / V3
Contenido en: Proceedings of the Biological Society of Washington Vol. 116, no. 2 (August 2003), p. 341-355
Bibliotecas: Campeche , Chetumal , San Cristóbal
Cerrar
SIBE Campeche
ECO040006410 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
ECO030004846 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
ECO010006280 (Disponible)
Disponibles para prestamo: 1
Resumen en: Inglés |
Resumen en inglés

The skull of the characid fish Astyanax mexicanus is described based on twenty alizarin-stained adult specimens from Río Salado, Río Conchos, Río Alamo, and Río San Juan populations, all of them Rio Grande tributaries in Northeastern Mexico. The skull has a circular shape in lateral view. The second infraorbital is triangular and never overlaps the inferior margin of the third infraorbital. The third infraorbital never reaches the laterosensory canal of the preopercular bone. The supraoccipital is short. The palatines, ectopterygoids and mesopterygoids lack teeth. We describe two features not reported in Astyanax before: teeth on the second suspensory pharyngeal and posterior gill rakers on the four gill arches. Differences in skull osteology between A. mexicanus and other described species of Astyanax are denoted.


8.
Capítulo de libro
Ictiogeografía de Yucatán, México
Schmitter Soto, Juan Jacobo ;
Clasificación: AR/597.0929 / S3
Contenido en: Libro jubilar en honor al Dr. Salvador Contreras Balderas Monterrey, Nuevo León, México : Universidad Autónoma de Nuevo León. Facultuad de Ciencias Biologicas, 2002 p. 103-116 ISBN:970-694-100-2
Cerrar
SIBE Campeche
ECO040001268 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
ECO030004680 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
ECO010018842 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
ECO020006164 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Villahermosa
ECO050004419 (Disponible)
Disponibles para prestamo: 1

9.
Artículo
Diagnosis of astyanax altior (Characidae), with a morphometric analysis of astyanax in the Yucatan Peninsula
Schmitter Soto, Juan Jacobo ;
Clasificación: AR/597.72 / S2
Contenido en: Ichthyological Exploration Of Freshwaters Vol. 8, no. 4 (February 1998), p. 349-358 ISSN: 0936-9902
Bibliotecas: Campeche , Chetumal , San Cristóbal
Cerrar
SIBE Campeche
ECO040001752 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
ECO030000397 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
ECO010018107 (Disponible)
Disponibles para prestamo: 1

10.
Tesis
Ictiogeografía histórica de las aguas interiores de la Península de Yucatán, con énfasis sobre la distribución de peces continentales en Quintana Roo / Juan Jacobo Schmitter Soto
Schmitter Soto, Juan Jacobo ;
México : Universidad Nacional Autónoma de México, Facultad de Ciencias, División de Estudios de Posgrado , 1998
Clasificación: TE/597.092 / S3
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
ECO030000300 (Disponible)
Disponibles para prestamo: 1