Alberto J. Sanchez - Academia.edu (original) (raw)

Papers by Alberto J. Sanchez

Hidrobiologica, Apr 15, 2016

Acta Ichthyologica et Piscatoria

The intake of microplastics by freshwater fishes has been scarcely studied, and it is not yet cle... more The intake of microplastics by freshwater fishes has been scarcely studied, and it is not yet clear whether the amount of particles these vertebrates ingest is associated with their feeding strategies. Hence, this study is focused on the suckermouth armored catfish (Pterygoplichthys spp.) under the hypothesis that, due to its detritivorous habits and demersal distribution, it may show evidence of the presence of microplastics in the sediments of a lake located in the Metropolitan Area of Villahermosa. A total of 21 organisms contained plastic microfibers throughout their digestive systems. These were treated with three solutions (hydrogen peroxide, potassium hydroxide, and sodium hypochlorite) to separate the microplastics. A total of 147 plastic particles of two categories were collected: microfibers (92%) and fragments (8%). Considering these results, as well as evidence in the literature, these species may constitute a global indicator of the incorporation into the trophic chain ...

Water

Water quality indicators have been tied to natural or man-made surface hydraulic connection (SHC)... more Water quality indicators have been tied to natural or man-made surface hydraulic connection (SHC) conditions. Among these, temporally connected lakes (TCL) are hydraulic intermediates between isolated (IL) and permanently connected lakes (PCL). Therefore, the aim of this study is to answer if water quality indicators can estimate the possible overlap between the two opposed conditions of SHC (IL and PCL) with the intermediate one (TCL) in lakes with similar modifications in the water level regulation at the basin level. Among nine water variables sampled in six lakes with the three SHC conditions mentioned, chlorophyll a (Chl-a), Secchi disk (SD), and total phosphorus (TP) were identified as quality water indicators through principal component analysis. Furthermore, said indicators were used to measure their overlap and trophic state index deviations. The Chl-a, SD, and TP values in TCL showed a 0.72 overlap of PCL and IL. TP surplus measured in all the lakes was meaningful in urban...

Ecosistemas y Recursos Agropecuarios, 2021

Se presenta una lista sistemática de peces recolectados durante 2014 y 2015 en la Reserva de la B... more Se presenta una lista sistemática de peces recolectados durante 2014 y 2015 en la Reserva de la Biosfera Pantanos de Centla con un incremento del 25% de su diversidad principalmente por la presencia de peces diádromos. El inventario comprende 75 especies, que representa el 37% de la ictiofauna en la cuenca Grijalva-Usumacinta, de las cuales cinco especies fueron no nativas invasoras donde el bagre armado (Pterygoplichthys spp.) fue el que presentó la mayor frecuencia de captura. Se identiﬁcaron 48 especies migratorias (38 diádromas y 10 potamodromas). La dominancia de peces diádromos y su presencia en sistemas de lagunas y ﬂuviales nos indica el mantenimiento de la interconexión hidráulica entre ríos y lagunas. En los muestreos, se observó la ausencia de siete especies dulceacuícolas que fueron comunes en publicaciones previas, lo anterior puede ser debido a la disminución de hábitats como consecuencia de las actividades humanas y la introducción de especies invasoras. En este estud...

Revista Internacional de Contaminación Ambiental, 2017

Studies on environmental pollution in Mexican freshwater ecosystems by means of fish histopatholo... more Studies on environmental pollution in Mexican freshwater ecosystems by means of fish histopathology are extremely scarce. In that view, this research analyzed the gonad histopathology of four teleost fish species from a hyper-eutrophicated fragmented urban lagoon, in order to determine possible harmful effects of water pollutants on their reproductive fitness. Gonads were processed by histological conventional techniques. The gonadal alterations detected in both, the clupeid Dorosoma petenense and the cichlid Thorichthys meeki expose the need to clarify the connection of these alterations to the presence of specific pollutants. Palabras clave: contaminación acuática, toxicología reproductiva, ovario, testículo, ictiofauna RESUMEN El diagnóstico ambiental de los ecosistemas dulceacuícolas a través de la histopatología de los peces ha sido poco abordado en México. Con base en lo anterior se realizó un análisis histopatológico de las gónadas de cuatro especies de teleósteos provenientes de una laguna urbana hipertrófica y fragmentada, con la finalidad de identificar posibles alteraciones reproductivas inducidas por contaminantes presentes en el agua. Las gónadas se procesaron con técnicas histológicas de rutina. Las alteraciones histopatológicas detectadas en las gónadas de Dorosoma petenense y Thorichthys meeki exponen la necesidad de establecer una conexión directa entre estas alteraciones con la presencia de contaminantes específicos. SHORT COMMUNICATION

Plants, 2020

A protocol for the induction of hairy roots on somatic embryos of rhizoclones from Typha domingen... more A protocol for the induction of hairy roots on somatic embryos of rhizoclones from Typha domingensis seedlings grown in hydroponic rhizotron systems was established for the first time. Rhizogenesis was induced through the agrotransformation of somatic embryos in oblong and scutellar states of development using the K599, LBA9402, and A4 strains of Agrobacterium rhizogenes. The transfection to the embryos was performed by cocultivation of rhizoclones on a Murashige and Skoog mineral medium at 50% strength (MS0.5), in the dark, at 28 ± 2 °C for 72 h. In contrast to nontransformed embryos that did not exhibit any root tissue, transformed embryos presented hairy roots that varied in number, length, and density depending on the bacterial strain, and K599 was the most effective strain. After analysis via optical microscopy, the transformed embryos were collected and transferred to fresh culture media supplemented with 400 mg mL−1 cefotaxime and 10 mg L−1 ascorbic acid. The efficiency of tr...

Agro Productividad, 2021

Objective: To study the conservation status of the tropical rainforest in the “Cañón del Usumacin... more Objective: To study the conservation status of the tropical rainforest in the “Cañón del Usumacinta” Flora and Fauna Protection Area in Mexico, through an analysis of the change in land use and vegetation (1997, 2009 and 2016). Design/Methodology/Approach: Vegetation and land use shapefiles at 1:250,000 scale (national continuum) corresponding to 1997 (series I), 2009 (series IV), and 2016 (series VI) were downloaded. Finally, a spatial analysis was generated with calculation of exchange rates, using the Land Change Modeler between 1997-2009 and 2009-2016. Results: During 1997-2009, the tropical rainforest occupied 31.2% and the greatest impact of the period seen was a change rate of 7.4%. Subsequently, between 2009 and 2016 there was a great decrease in the land use change rate in the forest (0.8%), due to its decree as a federal Protected Area in 2008, as well as natural regeneration and the promotion of ecological restoration programs. Study Limitations/Implications: Absence of g...

Hidrobiológica, 2019

Intra-annual variation of chlorophyll-a and nutrients in a hydraulically perturbed riverfloodplai... more Intra-annual variation of chlorophyll-a and nutrients in a hydraulically perturbed riverfloodplain system in the Grijalva River basin.

Revista de biología marina y oceanografía, 2018

Hypanus sabinus is reported in the limnetic environments in the coastal plain of the Southern Gul... more Hypanus sabinus is reported in the limnetic environments in the coastal plain of the Southern Gulf of Mexico. Eight specimens were collected 51 km away from the coastline in electric conductivity values less than 1,017 μS cm-1. One pregnant female and one male with two caudal spines are included. These findings represent the first limnetic records of this species in southern Mexico.

Gulf of Mexico Science, 2005

A total of 6,734 of peracarid crustaceans belonging to 3 orders (Amphipoda, Mysidacea, and Isopod... more A total of 6,734 of peracarid crustaceans belonging to 3 orders (Amphipoda, Mysidacea, and Isopoda), 17 families, 25 genera, and 30 species were recorded in the central region of Laguna Madre. The Amphipoda constituted 58% of total density (ind/m 2), whereas the Mysidacea and lsopoda represented 29 and 13%, respectively. The amphipods Cymadusa compta and Elasmopus levis, and the isopod Harrieta faxoni were the numerically dominant species, The maximum density values were recorded in submersed aquatic vegetation and sites close to the channels dm•ing the "norther" season, when the water temperature decreased.

Revista Mexicana de Biodiversidad, 2015

Los registros de 3,967 ejemplares de Pterygoplichthys spp. en 6 asociaciones de macrófitas acuáti... more Los registros de 3,967 ejemplares de Pterygoplichthys spp. en 6 asociaciones de macrófitas acuáticas en 6 zonas de humedales confirman su dispersión en la cuenca baja de los ríos Grijalva-Usumacinta. Los loricáridos en vegetación enraizada sumergida merecen mayor atención, pues representan un riesgo más para estas asociaciones de macrófitas acuáticas que albergan elevada biodiversidad. Derechos Reservados © 2015 Universidad Nacional Autónoma de México, Instituto de Biología. Este es un artículo de acceso abierto distribuido bajo los términos de la Licencia Creative Commons CC BY-NC-ND 4.0.

BioInvasions Records, 2015

Non-native South American suckermouth armored catfishes brackish waters of the genus Pterygoplich... more Non-native South American suckermouth armored catfishes brackish waters of the genus Pterygoplichthys are reported in the Chumpan River in the Southeastern Mexico. The Pterygoplichthys in the Chumpan likely dispersed from populations from the drainage of nearby coastal rivers where they were already established. These catfish tolerate estuarine conditions and probably dispersed from the Grijalva-Usumacinta basin through the brackish waters of Laguna de Términos and then ultimately entered the Chumpan River system. One juvenile and seven adult Pterygoplichthys were collected in the Chumpan River system in December 2014 from a river lagoon some 15 km upstream from Laguna de Términos. Non-native catfish were not detected in the nearby Candelaria River. Based on their ventral color patterns, the captured adult catfish were identified as a mix of Pterygoplichthys pardalis and hybrid Pterygoplichthys disjunctivus × pardalis. The detection of these invasive catfish in the Chumpan River highlights the urgent need to generate an awareness program to reduce any adverse effects of this invasive species in the basin, and raises concerns that they may disperse to other basins via an oligohaline passageway in Laguna de Términos.

Revista Mexicana de Biodiversidad

En las comunidades acuáticas, la complejidad del hábitat modifica la dinámica y la estructura, ya... more En las comunidades acuáticas, la complejidad del hábitat modifica la dinámica y la estructura, ya que la diversidad y abundancia aumentan conforme se incrementan las estructuras físicas emergentes del sustrato, como los troncos hundidos, que son sitios de refugio, alimentación y reproducción de la fauna asociada a esos hábitats. En 18 lagunas de Pantanos de Centla, Tabasco, donde se encontraron troncos hundidos, se realizaron 2 muestros manuales en la temporada de máxima inundación y 1 en la de mínima inundación. Se capturaron 1 228 crustáceos que pertenecen a 4 órdenes, 11 familias, 11 géneros y 13 especies, de los cuales los malacostracos predominaron con 12 especies. Las 13 especies de crustáceos registradas en este trabajo representaron el 17% de la carcinofauna capturada en los ecosistemas limnéticos del estado de Tabasco. El anfípodo Hyalella azteca fue numéricamente la especie dominante. La distribución de Balanus improvisus, Uhlorchestia ulheri, Platychirograpsus spectabilis, Armases cinereum y Goniopsis cruentata estuvo restringida principalmente a la zona de influencia marina. Balanus improvisus y Sphaeroma terebrans fueron las únicas especies sésiles y taladradoras recolectadas. Para las restantes 11 especies de crustáceos, los troncos hundidos también son un hábitat alternativo.

PeerJ

Background Sustainable methods of propagation of Typha domingensis through somatic embryogenesis ... more Background Sustainable methods of propagation of Typha domingensis through somatic embryogenesis can help mitigate its current condition of ecological marginalization and overexploitation. This study examined whether differentiation up to coleoptilar embryos could be obtained in an embryogenic line proliferated with light and high auxin concentration. Methods Murashige and Skoog medium at half ionic strength and containing 3% sucrose and 0.1% ascorbic acid was used for the three embryogenic phases. Induction started with aseptic 9-day-old germinated seeds cultured in 0.5 mg L−1 2,4-dichlorophenoxyacetic (2,4-D). Proliferation of the embryogenic callus was evaluated at 2,4-D concentrations ranging from 0 to 2 mg L−1 in cultures maintained in the dark. The dominant embryogenic products obtained in each treatment were used as embryogenic lines in the third phase. Thus, maturation of the somatic embryos (SEs) was analyzed using four embryogenic lines and under light vs. dark conditions....

Cuadernos Del Instituto De Biologia Unam, 1996

Revista Mexicana De Biodiversidad Vol 81 Suplemento, Sep 23, 2011

Hidrobiologica Revista Del Departamento De Hidrobiologia, 2003

RESUMEN En el año 2000, el dragado del canal de comunicación de la Laguna Mecoacán, Tabasco, infl... more RESUMEN En el año 2000, el dragado del canal de comunicación de la Laguna Mecoacán, Tabasco, influyó sobre la distribución la fauna acuática al modificar el volumen de intercambio de agua, los gradientes de salinidad y la dinámica de migrac entre los organismos estuarinos y marinos. Diez localidades se muestrearon bimestralmente en horas de iluminaci en febrero, abril, junio, agosto y octubre del 2000. Un total de 702 decápodos pertenecientes a nueve familias, géneros y 19 especies se capturaron con una red de arrastre tipo camaronera. Las especies dominantes en densid (ind/m 2) fueron Eurypanopeus depressus, Litopenaeus setiferus, Farfantepenaeus aztecus, F. duorarum y Clibanar vittatus. En cambio, en biomasa (g/m 2) dominaron los camarones, C. vittatus y la jaibas Callinectes rathbunae, C. sim y C. sapidus. La captura máxima de la densidad de crustáceos (61%) fue en la temporada de precipitación, y la máxim biomasa (57%) durante la sequía. La variación espacial de la salinidad registró un gradiente de sureste a norte y agrupó en tres zonas relacionadas con la descarga de los ríos. El 81% de las especies, el 87% de la densidad, y el 77 de la biomasa de decápodos se recolectaron en condiciones mesohalinas y polihalinas (zonas II y III), mientras q en condiciones oligo-mesohalinas (zona I) fueron menores. El menor número de especies de decápodos en Lagu Mecoacán, con respecto a otras lagunas costeras del suroccidente del Golfo de México, se atribuyó a la limita distribución de la vegetación acuática sumergida y a la prevalencia de condiciones oligohalinas y mesohalinas, don otros hábitat como los pastos marinos, macroalgas, bancos de mejillones y ostiones han disminuido drásticament los substratos lodosos son dominantes.