The endangered Chiapas killifish Tlaloc hildebrandi is an endemic freshwater species that lives i... more The endangered Chiapas killifish Tlaloc hildebrandi is an endemic freshwater species that lives in four subbasins of the Grijalva and Usumacinta basins, and one of the most geographically restricted species of the Produndulidae family. The species was originally described as endemic to springs in the high limestone plateau in San Cristóbal de Las Casas in the Río Amarillo subbasin (upper Grijalva basin). However, it was recently recorded in the Jataté and Tzaconejá subbasins in the upper Usumacinta basin, thereby expanding its known distribution range. The discovery of these populations is relevant not only for the conservation of the species but also for a better understanding of its evolutionary history. Currently, the scarce populations of T. hildebrandi, found in only a few localities in the Grijalva and Usumacinta basins, are fragmented and living under unfavorable conditions. Here, we analyzed three mitochondrial (mt-atp8&6 and mt-nd2) and one nuclear (nuc-s7) marker in order to assess the genetic diversity and population structure of T. hildebrandi. We found that, in comparison with other endangered freshwater fish species from Mexico, T. hildebrandi showed a lower level of genetic diversity (mt-nd2: h = 0.469, π = 0.0009; mt-atp8&6: h = 0.398, π = 0.001; and nuc-S7: h = 0.433, π = 0.001). Moreover, the analyzed populations exhibited a strong genetic structure in accordance with their geographic distribution, and can be placed into three genetic clusters: (1) Amarillo plus Chenhaló in the upper Grijalva basin, (2) Jataté, and (3) Tzaconejá, both in the upper Usumacinta basin. On the basis of our results, we propose the recognition of at least three evolutionarily significant units (ESUs) for How to cite this article
Resumen. Se evaluaron y compararon diversas características morfológicas de 6 especies de Vieja F... more Resumen. Se evaluaron y compararon diversas características morfológicas de 6 especies de Vieja Fernández-Yépez, 1969 del río Usumacinta. Se emplearon 20 organismos adultos por especie y 33 medidas corporales que fueron estandarizadas y examinadas con un análisis discriminante. Además se comparó la forma del cuerpo entre las especies, mediante el análisis de morfometría geométrica a partir de imágenes digitalizadas. El análisis con la morfometría tradicional y geométrica permitió diferenciar los seis taxones. Se encontraron 10 medidas discriminantes, que expresan diferencias significativas en la longitud de las aletas y la región cefálica, de las cuales la posición de la boca diferenció estadísticamente más taxones. Las relaciones de similitud con ambos análisis mostraron 2 grupos, siendo V. bifasciata (Steindachner, 1864) y V. synspila (Hubbs, 1935) las especies más parecidas. Las gradillas de deformación mostraron que la mayor variación está en la región cefálica, específicamente en la posición de la boca y los ojos. Las diferencias morfométricas encontradas pueden servir para la determinación taxonómica en trabajos futuros. La variación encontrada en la morfología cefálica y trófica puede ser un mecanismo que favorece la coexistencia de las especies y la diversidad del grupo en la región.
A systematic checklist is presented for the marine estuarine fishes of Chiapas, Mexico, including... more A systematic checklist is presented for the marine estuarine fishes of Chiapas, Mexico, including notes on their zoogeography and conservation status. The checklist includes 379 species, two classes, 30 orders, 91 families, and 207 genera. Actinopterygii is the most diverse class (323 species, 181 genera, 72 families, and 23 orders), while Chondrichthyes (56 species, 26 genera, 19 families, and seven orders) is the least diverse class. Perciformes is the richest order (175 species, 98 genera, and 32 families), including seven families representing 32.2% of the total fish diversity reported here: Sciaenidae (25 species), Carangidae (21), Gobiidae (20), Haemulidae (14), Epinephelidae (11), Dactyloscopidae (10), and Gerreidae (10). Based on a taxonomical review of specimens in fish collections and literature-verified records, the list is composed of marinestenohaline (46.7%), marine-euryhaline (48.8%), primary freshwater (1%), secondary freshwater (2.6%), and diadromous (0.2%) species. The ichthyofauna showed greater zoogeographic affinity to the Mexican (81.5%) and Panamic (80.5%) provinces, while 48 species are circumtropical, four amphipacific, five amphiamerican, and one exotic (Oreochromis niloticus). Based on the IUCN Red List, 259 species are of BLeast Concern^, 18 are BNear Threatened^, 11 are BVulnerable^, two are BCritically Endangered^(Pristis pectinata and P. pristis), and one is BEndangered^(Rhincodon typus); 23.2% are BNot Evaluatedô r BData Deficient^. Three species are under BSpecial Protection^and another three are BThreatened^under Mexican law NOM-059-SEMARNAT-2010. Nearly 75% of the teleostean and 25% of the cartilaginous fishes are of commercial value. Taxonomic identifications should be updated and the geographic distributions of Chiapas' coastal fish species should be documented in order to design and implement effective management and conservation programs.
Several species of Pterygoplichthys (Siluriformes: Loricariidae) have been introduced around the ... more Several species of Pterygoplichthys (Siluriformes: Loricariidae) have been introduced around the world and are now invasive outside of their native range. In southern Mexico, Pterygoplichthys is quickly spreading and has become one of the dominant groups of fishes in many freshwater ecosystems. We describe
Mexico is a megadiverse region with a complex geological history, but it remains unclear to what ... more Mexico is a megadiverse region with a complex geological history, but it remains unclear to what extent the distribution of freshwater fish has been influenced by geographic barriers. This study examines the population level genetic divergence and phylogenetic relationships of species in the shortfin group of the subgenus Mollienesia (genus Poecilia), a group of live-bearing fishes that are widely distributed across Mexico, with sampling at a small geographic scale. Samples from over 50 locations were analyzed for six species by using phylogenetic and haplotype network approaches to assess genetic diversity across geographic ranges and to refine the distributions of species in this group. The results indicate that Mexican species have diversified following multiple, independent invasions from Middle America. Two species found north of the Trans-Mexican Volcanic Belt (TMVB) and one transversal species exhibited weak phylogenetic structure, likely due to the lack of physiographic barriers, recent colonization, and high dispersal rates among regions. In contrast, three species found south of the TMVB exhibited strong phylogenetic structure, reflecting a longer presence in the area and multiple physiographic barriers that isolated populations. This study identified mechanisms driving divergence and speciation, expanded the known range of several species, and resolved taxonomic uncertainties of populations.
ABSTRACT Astyanax armandoi Lozano-Vilano and Contreras-Balderas, 1990, a characid described as en... more ABSTRACT 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. Astyanax armandoi Lozano-Vilano and Contreras-Balderas, 1990, un cará cido descrito como endé mico de un pequeñ o arroyo en el sur de Mé xico, se considera en este trabajo como sinó nimo de A. aeneus (Günther, 1860), especie de amplia distribució n en el norte de Centroamé rica. La diagnosis de A. armandoi se basa en su labio inferior expandido, junto con un conjunto de caracteres osteoló gicos. La expansió n labial se ha observado tambié n en otras poblaciones de Astyanax (en Campeche y en Chiapas, Mé xico) y se trata de un ecofenotipo, una adaptació n a condiciones de hipoxia. Los caracteres osteoló gicos, merísticos, y morfomé tricos de A. armandoi son compatibles con la notable variació n intra-e interpoblacional de A. aeneus. La localidad tipo ha sido visitada repetidamente durante la ú ltima dé cada sin que se hayan encontrado má s especímenes identificables como A. armandoi, só lo el típico A. aeneus. Esta conclusió n implica que A. armandoi debe borrarse de la Norma Oficial Mexicana (NOM-059-SEMARNAT-2001) y de listas similares de especies en peligro.
Resumen La cuenca del río Usumacinta se caracteriza por su gran extensión, heterogeneidad ecológi... more Resumen La cuenca del río Usumacinta se caracteriza por su gran extensión, heterogeneidad ecológica y alta biodiversidad. Con el objetivo de documentar de manera integral la riqueza y distribución de la ictiofauna, se incluyen en este trabajo los registros para la cuenca (1994-2014) depositados en la Colección de Peces (ECOSC), además de la revisión bibliográfica y de los registros de otras bases de datos nacionales e internacionales. Adicionalmente y con la finalidad de analizar la diversidad y abundancia, se realizaron muestreos (2014 y 2015) en 3 zonas: selva, planicie y delta. La ictiofauna se compone de 2 clases, 28 órdenes, 50 familias y 172 especies, de las cuales 3 son nuevos registros. De acuerdo a su afinidad ecológica, 75 especies son dulceacuícolas, 8 estuarinas y 89 marinas. La zona selva tuvo más especies dulceacuícolas exclusivas y la zona delta registró la mayor riqueza de peces marinos. Los cambios observados en la diversidad a lo largo de las 3 zonas están influidos por la historia geológica, dinámica hidrológica y su conectividad con el golfo de México. Es necesario continuar con el estudio de la ictiofauna en función de la complejidad geomorfológica para entender patrones biogeográficos, así como procesos ecológicos importantes para su conservación.
Located within Mexico’s Montes Azules Biosphere Reserve, the Tzendales River is part of the Usuma... more Located within Mexico’s Montes Azules Biosphere Reserve, the Tzendales River is part of the Usumacinta River Basin, which supports the largest diversity of cichlid fishes in Middle America. We evaluated temporal and spatial variation of species richness and distribution of cichlids in the Tzendales River; we collected 14 species with nine native and five endemic. The species with greatest relative
Patterns in the Species Diversity and Composition of the Fish Community of the Lacanja River, Chi... more Patterns in the Species Diversity and Composition of the Fish Community of the Lacanja River, Chiapas, Mexico Rocio Rodiles-Hernandez El ... Angermeier and Karr 1983, Burcham 1988, Angermeier and Schlosser 1989, Lyons and Schneider 1990, Winemiller and Leslie 1990). ...
Journal of Aquaculture & Marine Biology, May 11, 2017
The taxonomy and distribution of 2 deep water sharks, Mustelus sinusmexicanus and Hexanchus nakam... more The taxonomy and distribution of 2 deep water sharks, Mustelus sinusmexicanus and Hexanchus nakamurai, is discussed here on the basis of 3 specimens from the Gulf of Mexico. Both species aredistributed in the area; however, they are rarely found in ichthyological collections as they are seldomcaught and due to the challenge of curating such large specimens. Thus, this is the first time that GulfSmooth hound and Bigeye Sixgill shark specimens have been curated in a Mexican ichthyologicalcollection, confirming its presence in México.
This chapter discusses the physical and biological features of five major Mexican rivers—the Rio ... more This chapter discusses the physical and biological features of five major Mexican rivers—the Rio Panuco, Usumacinta–Grijalva rivers, Rio Candelaria, the Yaqui, and the Rio Conchos. Five additional rivers—the Chihuahuan Desert's Rio Salado; the Rio Tamesi, which joins the Rio Panuco near its mouth; the Rio Fuerte, which flows through some of the continent's largest canyons in the Sierra Madre Occidental to the Gulf of California south of the Yaqui and Mayo rivers; the Ayuquila–Armeria river system, which empties into the Pacific Ocean; and the Rio Lacanja, a small mountainous tributary of the Usumacinta—are also briefly reviewed. The history of human impacts on Mexico's rivers includes many groups of prehistoric inhabitants. Mexico's major rivers are highly exploited. Construction of dams, primarily for crop irrigation in otherwise desert environments, is one of the major factors. Water pollution from discharge of domestic wastes, high salinity, and nutrients from irrigation returns, mining, and industrial wastes is widespread throughout Mexico. With the increase in population and associated land-use change and generally limited resources available for conservation of natural resources the scenario of the rivers are becoming much worse.
Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, Jan 5, 2020
Together, the complex geological history and climatic diversity of Mesoamerica create a rich sour... more 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.
A new family (Lacantuniidae), genus and species of catfish, Lacantunia enigmatica, is described f... more A new family (Lacantuniidae), genus and species of catfish, Lacantunia enigmatica, is described from the Río Usumacinta basin of Chiapas, México. This odd siluriform is diagnosed by five distinctively autapomorphic and anatomically complex structures. The fifth (last) infraorbital bone is relatively large, anteriorly convex and remote from a prominent sphenotic process. The lateral margin of the frontal, lateral ethmoid and sphenotic bones are thick at the origins of much enlarged adductor mandibulae and levator arcus palatini muscles; otherwise the skull roof is constricted and flat. One pair of cone-shaped "pseudo-pharyngobranchial" bones is present at the anterior tips of enlarged cartilages medial to the first epibranchial. A hypertrophied, axe-shaped uncinate process emerges dorsally from the third epibranchial. The gas bladder has paired spherical, unencapsulated diverticulae protruding from its anterodorsal wall. Lacantunia enigmatica cannot be placed within or as a basal sister lineage to any known catfish family or multifamily clade except Siluroidei. This species may represent an ancient group, perhaps of early Tertiary age or older, and it adds another biogeographic puzzle to the historically complex Mesoamerican biota.
El sistema hidrológico Mezcalapa-Grijalva-Usumacinta ha sufrido modificaciones continuas en sus r... more El sistema hidrológico Mezcalapa-Grijalva-Usumacinta ha sufrido modificaciones continuas en sus redes fluviales desde el siglo XVII. La alteración del balance hidro-sedimentario ha incidido en la morfodinámica del delta con impactos evidentes en la evolución de la línea de costa. Los archivos y la cartografía histórica permiten evaluar dichas alteraciones del medio a distintas resoluciones espaciales y temporales. Los resultados muestran que documentos, archivos, mapas históricos y fotografías aéreas son herramientas valiosas en apoyo a la comprensión de procesos ecológicos alterados en grandes cuencas.
The endangered Chiapas killifish Tlaloc hildebrandi is an endemic freshwater species that lives i... more The endangered Chiapas killifish Tlaloc hildebrandi is an endemic freshwater species that lives in four subbasins of the Grijalva and Usumacinta basins, and one of the most geographically restricted species of the Produndulidae family. The species was originally described as endemic to springs in the high limestone plateau in San Cristóbal de Las Casas in the Río Amarillo subbasin (upper Grijalva basin). However, it was recently recorded in the Jataté and Tzaconejá subbasins in the upper Usumacinta basin, thereby expanding its known distribution range. The discovery of these populations is relevant not only for the conservation of the species but also for a better understanding of its evolutionary history. Currently, the scarce populations of T. hildebrandi, found in only a few localities in the Grijalva and Usumacinta basins, are fragmented and living under unfavorable conditions. Here, we analyzed three mitochondrial (mt-atp8&6 and mt-nd2) and one nuclear (nuc-s7) marker in order to assess the genetic diversity and population structure of T. hildebrandi. We found that, in comparison with other endangered freshwater fish species from Mexico, T. hildebrandi showed a lower level of genetic diversity (mt-nd2: h = 0.469, π = 0.0009; mt-atp8&6: h = 0.398, π = 0.001; and nuc-S7: h = 0.433, π = 0.001). Moreover, the analyzed populations exhibited a strong genetic structure in accordance with their geographic distribution, and can be placed into three genetic clusters: (1) Amarillo plus Chenhaló in the upper Grijalva basin, (2) Jataté, and (3) Tzaconejá, both in the upper Usumacinta basin. On the basis of our results, we propose the recognition of at least three evolutionarily significant units (ESUs) for How to cite this article
Resumen. Se evaluaron y compararon diversas características morfológicas de 6 especies de Vieja F... more Resumen. Se evaluaron y compararon diversas características morfológicas de 6 especies de Vieja Fernández-Yépez, 1969 del río Usumacinta. Se emplearon 20 organismos adultos por especie y 33 medidas corporales que fueron estandarizadas y examinadas con un análisis discriminante. Además se comparó la forma del cuerpo entre las especies, mediante el análisis de morfometría geométrica a partir de imágenes digitalizadas. El análisis con la morfometría tradicional y geométrica permitió diferenciar los seis taxones. Se encontraron 10 medidas discriminantes, que expresan diferencias significativas en la longitud de las aletas y la región cefálica, de las cuales la posición de la boca diferenció estadísticamente más taxones. Las relaciones de similitud con ambos análisis mostraron 2 grupos, siendo V. bifasciata (Steindachner, 1864) y V. synspila (Hubbs, 1935) las especies más parecidas. Las gradillas de deformación mostraron que la mayor variación está en la región cefálica, específicamente en la posición de la boca y los ojos. Las diferencias morfométricas encontradas pueden servir para la determinación taxonómica en trabajos futuros. La variación encontrada en la morfología cefálica y trófica puede ser un mecanismo que favorece la coexistencia de las especies y la diversidad del grupo en la región.
A systematic checklist is presented for the marine estuarine fishes of Chiapas, Mexico, including... more A systematic checklist is presented for the marine estuarine fishes of Chiapas, Mexico, including notes on their zoogeography and conservation status. The checklist includes 379 species, two classes, 30 orders, 91 families, and 207 genera. Actinopterygii is the most diverse class (323 species, 181 genera, 72 families, and 23 orders), while Chondrichthyes (56 species, 26 genera, 19 families, and seven orders) is the least diverse class. Perciformes is the richest order (175 species, 98 genera, and 32 families), including seven families representing 32.2% of the total fish diversity reported here: Sciaenidae (25 species), Carangidae (21), Gobiidae (20), Haemulidae (14), Epinephelidae (11), Dactyloscopidae (10), and Gerreidae (10). Based on a taxonomical review of specimens in fish collections and literature-verified records, the list is composed of marinestenohaline (46.7%), marine-euryhaline (48.8%), primary freshwater (1%), secondary freshwater (2.6%), and diadromous (0.2%) species. The ichthyofauna showed greater zoogeographic affinity to the Mexican (81.5%) and Panamic (80.5%) provinces, while 48 species are circumtropical, four amphipacific, five amphiamerican, and one exotic (Oreochromis niloticus). Based on the IUCN Red List, 259 species are of BLeast Concern^, 18 are BNear Threatened^, 11 are BVulnerable^, two are BCritically Endangered^(Pristis pectinata and P. pristis), and one is BEndangered^(Rhincodon typus); 23.2% are BNot Evaluatedô r BData Deficient^. Three species are under BSpecial Protection^and another three are BThreatened^under Mexican law NOM-059-SEMARNAT-2010. Nearly 75% of the teleostean and 25% of the cartilaginous fishes are of commercial value. Taxonomic identifications should be updated and the geographic distributions of Chiapas' coastal fish species should be documented in order to design and implement effective management and conservation programs.
Several species of Pterygoplichthys (Siluriformes: Loricariidae) have been introduced around the ... more Several species of Pterygoplichthys (Siluriformes: Loricariidae) have been introduced around the world and are now invasive outside of their native range. In southern Mexico, Pterygoplichthys is quickly spreading and has become one of the dominant groups of fishes in many freshwater ecosystems. We describe
Mexico is a megadiverse region with a complex geological history, but it remains unclear to what ... more Mexico is a megadiverse region with a complex geological history, but it remains unclear to what extent the distribution of freshwater fish has been influenced by geographic barriers. This study examines the population level genetic divergence and phylogenetic relationships of species in the shortfin group of the subgenus Mollienesia (genus Poecilia), a group of live-bearing fishes that are widely distributed across Mexico, with sampling at a small geographic scale. Samples from over 50 locations were analyzed for six species by using phylogenetic and haplotype network approaches to assess genetic diversity across geographic ranges and to refine the distributions of species in this group. The results indicate that Mexican species have diversified following multiple, independent invasions from Middle America. Two species found north of the Trans-Mexican Volcanic Belt (TMVB) and one transversal species exhibited weak phylogenetic structure, likely due to the lack of physiographic barriers, recent colonization, and high dispersal rates among regions. In contrast, three species found south of the TMVB exhibited strong phylogenetic structure, reflecting a longer presence in the area and multiple physiographic barriers that isolated populations. This study identified mechanisms driving divergence and speciation, expanded the known range of several species, and resolved taxonomic uncertainties of populations.
ABSTRACT Astyanax armandoi Lozano-Vilano and Contreras-Balderas, 1990, a characid described as en... more ABSTRACT 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. Astyanax armandoi Lozano-Vilano and Contreras-Balderas, 1990, un cará cido descrito como endé mico de un pequeñ o arroyo en el sur de Mé xico, se considera en este trabajo como sinó nimo de A. aeneus (Günther, 1860), especie de amplia distribució n en el norte de Centroamé rica. La diagnosis de A. armandoi se basa en su labio inferior expandido, junto con un conjunto de caracteres osteoló gicos. La expansió n labial se ha observado tambié n en otras poblaciones de Astyanax (en Campeche y en Chiapas, Mé xico) y se trata de un ecofenotipo, una adaptació n a condiciones de hipoxia. Los caracteres osteoló gicos, merísticos, y morfomé tricos de A. armandoi son compatibles con la notable variació n intra-e interpoblacional de A. aeneus. La localidad tipo ha sido visitada repetidamente durante la ú ltima dé cada sin que se hayan encontrado má s especímenes identificables como A. armandoi, só lo el típico A. aeneus. Esta conclusió n implica que A. armandoi debe borrarse de la Norma Oficial Mexicana (NOM-059-SEMARNAT-2001) y de listas similares de especies en peligro.
Resumen La cuenca del río Usumacinta se caracteriza por su gran extensión, heterogeneidad ecológi... more Resumen La cuenca del río Usumacinta se caracteriza por su gran extensión, heterogeneidad ecológica y alta biodiversidad. Con el objetivo de documentar de manera integral la riqueza y distribución de la ictiofauna, se incluyen en este trabajo los registros para la cuenca (1994-2014) depositados en la Colección de Peces (ECOSC), además de la revisión bibliográfica y de los registros de otras bases de datos nacionales e internacionales. Adicionalmente y con la finalidad de analizar la diversidad y abundancia, se realizaron muestreos (2014 y 2015) en 3 zonas: selva, planicie y delta. La ictiofauna se compone de 2 clases, 28 órdenes, 50 familias y 172 especies, de las cuales 3 son nuevos registros. De acuerdo a su afinidad ecológica, 75 especies son dulceacuícolas, 8 estuarinas y 89 marinas. La zona selva tuvo más especies dulceacuícolas exclusivas y la zona delta registró la mayor riqueza de peces marinos. Los cambios observados en la diversidad a lo largo de las 3 zonas están influidos por la historia geológica, dinámica hidrológica y su conectividad con el golfo de México. Es necesario continuar con el estudio de la ictiofauna en función de la complejidad geomorfológica para entender patrones biogeográficos, así como procesos ecológicos importantes para su conservación.
Located within Mexico’s Montes Azules Biosphere Reserve, the Tzendales River is part of the Usuma... more Located within Mexico’s Montes Azules Biosphere Reserve, the Tzendales River is part of the Usumacinta River Basin, which supports the largest diversity of cichlid fishes in Middle America. We evaluated temporal and spatial variation of species richness and distribution of cichlids in the Tzendales River; we collected 14 species with nine native and five endemic. The species with greatest relative
Patterns in the Species Diversity and Composition of the Fish Community of the Lacanja River, Chi... more Patterns in the Species Diversity and Composition of the Fish Community of the Lacanja River, Chiapas, Mexico Rocio Rodiles-Hernandez El ... Angermeier and Karr 1983, Burcham 1988, Angermeier and Schlosser 1989, Lyons and Schneider 1990, Winemiller and Leslie 1990). ...
Journal of Aquaculture & Marine Biology, May 11, 2017
The taxonomy and distribution of 2 deep water sharks, Mustelus sinusmexicanus and Hexanchus nakam... more The taxonomy and distribution of 2 deep water sharks, Mustelus sinusmexicanus and Hexanchus nakamurai, is discussed here on the basis of 3 specimens from the Gulf of Mexico. Both species aredistributed in the area; however, they are rarely found in ichthyological collections as they are seldomcaught and due to the challenge of curating such large specimens. Thus, this is the first time that GulfSmooth hound and Bigeye Sixgill shark specimens have been curated in a Mexican ichthyologicalcollection, confirming its presence in México.
This chapter discusses the physical and biological features of five major Mexican rivers—the Rio ... more This chapter discusses the physical and biological features of five major Mexican rivers—the Rio Panuco, Usumacinta–Grijalva rivers, Rio Candelaria, the Yaqui, and the Rio Conchos. Five additional rivers—the Chihuahuan Desert's Rio Salado; the Rio Tamesi, which joins the Rio Panuco near its mouth; the Rio Fuerte, which flows through some of the continent's largest canyons in the Sierra Madre Occidental to the Gulf of California south of the Yaqui and Mayo rivers; the Ayuquila–Armeria river system, which empties into the Pacific Ocean; and the Rio Lacanja, a small mountainous tributary of the Usumacinta—are also briefly reviewed. The history of human impacts on Mexico's rivers includes many groups of prehistoric inhabitants. Mexico's major rivers are highly exploited. Construction of dams, primarily for crop irrigation in otherwise desert environments, is one of the major factors. Water pollution from discharge of domestic wastes, high salinity, and nutrients from irrigation returns, mining, and industrial wastes is widespread throughout Mexico. With the increase in population and associated land-use change and generally limited resources available for conservation of natural resources the scenario of the rivers are becoming much worse.
Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, Jan 5, 2020
Together, the complex geological history and climatic diversity of Mesoamerica create a rich sour... more 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.
A new family (Lacantuniidae), genus and species of catfish, Lacantunia enigmatica, is described f... more A new family (Lacantuniidae), genus and species of catfish, Lacantunia enigmatica, is described from the Río Usumacinta basin of Chiapas, México. This odd siluriform is diagnosed by five distinctively autapomorphic and anatomically complex structures. The fifth (last) infraorbital bone is relatively large, anteriorly convex and remote from a prominent sphenotic process. The lateral margin of the frontal, lateral ethmoid and sphenotic bones are thick at the origins of much enlarged adductor mandibulae and levator arcus palatini muscles; otherwise the skull roof is constricted and flat. One pair of cone-shaped "pseudo-pharyngobranchial" bones is present at the anterior tips of enlarged cartilages medial to the first epibranchial. A hypertrophied, axe-shaped uncinate process emerges dorsally from the third epibranchial. The gas bladder has paired spherical, unencapsulated diverticulae protruding from its anterodorsal wall. Lacantunia enigmatica cannot be placed within or as a basal sister lineage to any known catfish family or multifamily clade except Siluroidei. This species may represent an ancient group, perhaps of early Tertiary age or older, and it adds another biogeographic puzzle to the historically complex Mesoamerican biota.
El sistema hidrológico Mezcalapa-Grijalva-Usumacinta ha sufrido modificaciones continuas en sus r... more El sistema hidrológico Mezcalapa-Grijalva-Usumacinta ha sufrido modificaciones continuas en sus redes fluviales desde el siglo XVII. La alteración del balance hidro-sedimentario ha incidido en la morfodinámica del delta con impactos evidentes en la evolución de la línea de costa. Los archivos y la cartografía histórica permiten evaluar dichas alteraciones del medio a distintas resoluciones espaciales y temporales. Los resultados muestran que documentos, archivos, mapas históricos y fotografías aéreas son herramientas valiosas en apoyo a la comprensión de procesos ecológicos alterados en grandes cuencas.
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