WorldWideScience

Sample records for chirostoma humboldtianum atheriniformes

  1. The complete mitochondrial DNA of the endemic shortfin silverside, Chirostoma humboldtianum (Valenciennes, 1835).

    Science.gov (United States)

    Barriga-Sosa, Irene de los A; De León, Francisco J García; Del Río-Portilla, Miguel A

    2016-01-01

    The shortfin silverside Chirostoma humboldtianum, is an endemic fish from the Mesa Central of Mexico, it is considered the "ancestral" species of the "peces blancos" and plays an important role as a potential species for aquaculture. Here we sequence its mitogenome (Genbank accession number KJ921739), which has a total length of 16,447 bp, and the arrangement consist of 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes and 22 transfer RNA similar to other Atheriniformes. This mitogenome will be useful for phylogenetic, population and phylogeographic studies of this and other important atherinopsid species. PMID:25185796

  2. Isolation and characterization of microsatellite loci in the Charal de Xochimilco Chirostoma humboldtianum

    OpenAIRE

    Rosa María García-Martínez; Francisco Javier García-De León; Omar Mejía; Irene de los Ángeles Barriga-Sosa

    2014-01-01

    Microsatellite loci were isolated and characterized for the endemic fish Chirostoma humboldtianum using an enrichment procedure. Eight polymorphic microsatellites were genotyped for 32 - 48 individuals from Tepuxtepec Dam, Michoacán. The number of alleles per locus ranged from 3 to 11 and the average observed and expected heterozygosities were 0.61 and 0.63, respectively. All loci deviated significantly from Hardy-Weinberg expectations, which might be related to small population sizes associa...

  3. Antibiotic and heavy metal resistance of Aeromonas hydrophila isolated from charal (Chirostoma humboldtianum, Valenciannes, 1835)

    OpenAIRE

    Gloria Luz Paniagua; Eric Monroy; Magdalena Perches; Erasmo Negrete; Octavio García; Sergio Vaca

    2006-01-01

    Antibiotic and heavy metal susceptibilities of twenty Aeromonas hydrophila strains, isolated from the gastrointestinal tract of the charal (Chirostoma humboldtianum), an autochthonous Mexican fish, were analyzed. All strains produced #946;-lactamase and were resistant to penicillin and dicloxacillin, showing single peak for minimum inhibitory concentration (MIC) distributions at 2000-4000 µg/mL and 500-1000 µg/ml, respectively. Ampicillin MIC distribution was bimodal with 20% resistant strai...

  4. Multi-locus fossil-calibrated phylogeny of Atheriniformes (Teleostei, Ovalentaria).

    Science.gov (United States)

    Campanella, Daniela; Hughes, Lily C; Unmack, Peter J; Bloom, Devin D; Piller, Kyle R; Ortí, Guillermo

    2015-05-01

    Phylogenetic relationships among families within the order Atheriniformes have been difficult to resolve on the basis of morphological evidence. Molecular studies so far have been fragmentary and based on a small number taxa and loci. In this study, we provide a new phylogenetic hypothesis based on sequence data collected for eight molecular markers for a representative sample of 103 atheriniform species, covering 2/3 of the genera in this order. The phylogeny is calibrated with six carefully chosen fossil taxa to provide an explicit timeframe for the diversification of this group. Our results support the subdivision of Atheriniformes into two suborders (Atherinopsoidei and Atherinoidei), the nesting of Notocheirinae within Atherinopsidae, and the monophyly of tribe Menidiini, among others. We propose taxonomic changes for Atherinopsoidei, but a few weakly supported nodes in our phylogeny suggests that further study is necessary to support a revised taxonomy of Atherinoidei. The time-calibrated phylogeny was used to infer ancestral habitat reconstructions to explain the current distribution of marine and freshwater taxa. Based on these results, the current distribution of Atheriniformes is likely due to widespread marine dispersal along the margins of continents, infrequent trans-oceanic dispersal, and repeated invasion of freshwater habitats. This conclusion is supported by post-Gondwanan divergence times among families within the order, and a high probability of a marine ancestral habitat. PMID:25769409

  5. Stable isotope evidence for trophic overlap of sympatric Mexican Lake Chapala silversides (Teleostei: Atherinopsidae: Chirostoma spp.

    Directory of Open Access Journals (Sweden)

    Norman Mercado-Silva

    2015-06-01

    Full Text Available We explore the trophic role that a diverse sympatric group of fishes in the genus Chirostoma play in a large, shallow lake in central Mexico, Lake Chapala. We use δ13C and δ15N stable isotope - based food web analyses to explore how they relate to other components of the Lake Chapala ecosystem. We find five Chirostoma species in top trophic levels of the Chapala food web compared to other fishes, relying on a combination of zooplankton, fish and benthic resources as energy sources. Food web metric analyses showed generally overlapping trophic niches for members of Chirostoma, especially in terms of δ13C. However, C. jordani had lower mean δ15N isotopic values than C. promelas. As a group, "pescados blancos" (C. sphyraena and C. promelas also had higher δ15N signatures than "charales" (C. consocium, C. jordani and C. labarcae reflecting greater piscivory, but these differences were not strong for all food web metrics used. Trophic overlap among species of Chirostoma in Lake Chapala raises questions about the forces that might have led to a morphologically diverse but functionally similar and monophyletic group of species.

  6. Efecto de la salinidad en la sobrevivencia de peces silvestres del género Chirostoma durante el transporte y mantenimiento en laboratorio

    OpenAIRE

    Guillermo Artemio Blancas-Arroyo; Rocío Frías-Sevilla; Eréndira De la Rosa-Pimentel; Virginia Suárez-Navarro; José Rodolfo Castro-Gómez; Javier Magaña-Morales

    2014-01-01

    Se comprobó el efecto de la salinidad en la sobrevivencia de peces silvestres del género Chirostoma, durante su transporte y aclimatación. Estos organismos son endémicos de México y conocidos como peces blancos y charales; los cuales se han caracterizado por su hipersensibilidad al manejo y su alto grado de estrés. Los modelos biológicos fueron dos especies de charales: Chirostoma jordani de Xochimilco cuenca de México y C. chapalae de Queréndaro subcuenca de Cuitzeo Michoacán. Se transportar...

  7. Comparación del efecto anestésico del aceite de clavo, solución salina y solución coloidal en juveniles de Chirostoma jordani (Woolman, 1894) Comparison of anaesthetic effect of clove oil, saline solution and colloidal solution in juvenile Chirostoma jordani (Woolman, 1894)

    OpenAIRE

    G. Vázquez; Castro, T.; Hernández, A.; Castro, J.; Lara, R.

    2013-01-01

    Los peces de la especie Chirostoma jordani presentan un intenso estrés durante las prácticas de manejo, dejándolos susceptibles a enfermedades y a tasas altas de mortalidad. El objetivo del presente estudio fue comparar el efecto anestésico del aceite de clavo, solución salina y una solución coloidal (Pentabiocare) en juveniles de Chirostoma jordani. Para cada tratamiento se utilizaron 18 ejemplares de C. jordani de dos meses de edad. Los tratamientos constaron en aceite de clavo (5, 8, 13 y ...

  8. Comparación del efecto anestésico del aceite de clavo, solución salina y solución coloidal en juveniles de Chirostoma jordani (Woolman, 1894)

    OpenAIRE

    G. Vázquez; Castro, T.; Hernández, A.; Castro, J.; Lara, R.

    2013-01-01

    Los peces de la especie Chirostoma jordani presentan un intenso estrés durante las prácticas de manejo, dejándolos susceptibles a enfermedades y a tasas altas de mortalidad. El objetivo del presente estudio fue comparar el efecto anestésico del aceite de clavo, solución salina y una solución coloidal (Pentabiocare) en juveniles de Chirostoma jordani. Para cada tratamiento se utilizaron 18 ejemplares de C. jordani de dos meses de edad. Los tratamientos constaron en aceite de clavo (5, 8, 13 y ...

  9. Spatial patterns of zooplanktivore Chirostoma species (Atherinopsidae during water-level fluctuation in the shallow tropical Lake Chapala, Mexico: seasonal and interannual analysis

    Directory of Open Access Journals (Sweden)

    Rodrigo Moncayo-Estrada

    2011-01-01

    Full Text Available This study addresses the influence of water-level fluctuations on fish distribution at two temporal scales: seasonal (dry and rainy and interannual (low and high volume conditions. The analysis of abundance relationships among three zooplanktivore Chirostoma species at fifteen sites in Lake Chapala, Mexico, revealed the significant influence of contrasting conditions (P=0.0002. Seasonally, segregation was more related to species dominance in the dry season and exclusively related to environmental characteristics in the rainy season. Interanually, biotic influence occurred in the shallowest and the deepest episodes of the lake. Environmental characteristics influenced species distribution when the lake reached 25% of its volume. Site, depth, temperature, and salinity were the leading factors influencing fish distribution. These results emphasize the necessity to implement different management strategies according to lake volume, particularly when a critical threshold is reached.El presente estudio describe la influencia que tiene la fluctuación del nivel del agua en la distribución de los peces a dos diferentes escalas: estacional (estiaje y lluvias e interanual (condiciones de bajo y alto volumen. El análisis de las relaciones de abundancia entre tres especies zooplanctófagas de Chirostoma en quince sitios del Lago de Chapala, México, reveló una influencia estadísticamente significativa en las condiciones contrastantes (P=0.0002. Estacionalmente, la segregación estuvo más relacionada a la dominancia de las especies en la época de estiaje y exclusivamente relacionada a las características ambientales en la época de lluvias. Interanualmente, la influencia biótica se presenta en los episodios más someros y más profundos del lago. Las características ambientales influenciaron la distribución de las especies cuando el lago alcanzó el 25% de su volumen. El sitio geográfico, profundidad, temperatura y salinidad fueron los principales

  10. Comparación del efecto anestésico del aceite de clavo, solución salina y solución coloidal en juveniles de Chirostoma jordani (Woolman, 1894 Comparison of anaesthetic effect of clove oil, saline solution and colloidal solution in juvenile Chirostoma jordani (Woolman, 1894

    Directory of Open Access Journals (Sweden)

    G Vázquez

    2013-01-01

    Full Text Available Los peces de la especie Chirostoma jordani presentan un intenso estrés durante las prácticas de manejo, dejándolos susceptibles a enfermedades y a tasas altas de mortalidad. El objetivo del presente estudio fue comparar el efecto anestésico del aceite de clavo, solución salina y una solución coloidal (Pentabiocare en juveniles de Chirostoma jordani. Para cada tratamiento se utilizaron 18 ejemplares de C. jordani de dos meses de edad. Los tratamientos constaron en aceite de clavo (5, 8, 13 y 25 µL/L, solución salina (7 g/L y solución coloidal (5 mL/L. Durante seis horas se registraron, en los peces, las fases de inducción a la anestesia y los tiempos de recuperación. Las concentraciones altas y los tiempos prolongados de exposición al aceite de clavo se asociaron a las fases profundas de la anestesia. La concentración de 25 µL/L de aceite de clavo indujo a los organismos a la fase tres y a partir de la tercer hora de exposición éstos entraron en la fase cinco, mientras que las soluciones salina y coloidal indujeron a los peces a la fase uno de sedación mostrando los lapsos más prolongados (seis horas. El tiempo de recuperación de los juveniles en la concentración de 25 µL/L de aceite de clavo se extendió a 3.006,0 ± 5,3 segundos, mientras que con solución salina y coloidal, la respuesta de los peces a la recuperación del ritmo opercular, reactividad a estímulos externos y natación activa fue entre 60 a 180 segundos. Los resultados de este experimento indicaron que la solución salina y solución coloidal mantuvieron a los juveniles de C. jordani en una sedación ligera durante un lapso de seis horas con tiempos breves de recuperación. El uso de aceite de clavo en dosis de 5 y 13 µL/L indujo a los juveniles a estados de anestesia ligera y profunda respectivamente, con una recuperación de no más de 420 segundos.The fish Chirostoma jordani undergoes intense stress during handling practices, making it susceptible to

  11. Growth hormone-insuline-like growth factor-I system in pejerrey Odontesthes bonariensis (Atheriniformes

    Directory of Open Access Journals (Sweden)

    S.E. Arranz

    2008-07-01

    Full Text Available Using biotechnology to increase the growth rates of fish is likely to reduce production costs per unit of food. Among vertebrates, fish appear to occupy a unique position, when growth patterns are considered. With few exceptions, fish species tend to grow indeterminately, implying that size is never fixed. Both hyperplasia and hypertrophy contribute to post-larval muscle growth in fish. Growth hormone (GH - Insulin-like Growth Factor I (IGF-I is the most important growth axis in fish. Our experimental model, the pejerrey, Odontesthes bonariensis (Ateriniformes is a South American inland water fish considered to be a promising species for intensive aquaculture. However, one major drawback to achieve this goal is its slow growth in captivity. In order to understand how growth is regulated in this species, our first objective was to characterized pejerrey GH- IGF-I axis. We first cloned and characterized pejerrey (pj GH, IGF-I and the growth hormone receptors (GHRs I and II. In addition to providing valuable data for evolutionary comparison of GH, investigation of GH action in teleosts is particularly important because of its potential application in aquaculture. GH can not only promote the somatic growth in fish but also lower dietary protein requirements. A prerequisite for providing sufficient amounts of GH for basic research and aquaculture application is a large-scale production of GH. For that purpose, recombinant pjGH was expressed in a bacterial system. Protocols for solubilization and proper folding were achieved. Activity of recombinant pjGH was assessed in fish by measuring the liver IGF-I response to different doses of GH. IGF-I transcript was measured in the liver after pjGHr in vivo stimulation by means of quantitative real-time PCR assays. A dose-dependent response of IGF-I mRNA was observed after pjGHr administration, and reached a 6 fold IGF-I maximum increase over control group when 2.5 µg pjGH /g-body weight were injected. Temporal analysis of hepatic IGF-I mRNA levels showed that administration of a single dose of pjGHr into juvenile pejerrey resulted in a significant increase (P<0.02 9 hours post injection. These results demonstrates that recombinant pjGH could promote a dramatic response in liver, increasing the IGF-I mRNA level. We also study the effect of GH on muscle growth after oral administration. A significant association between GH doses and mean fiber area (MFA was observed even with a caloric restrictive diet. MFA increased 3.7 µm² per each unit of GH supplied indicating that GH promoted white muscle hypertrophy. These preliminary data indicates that GH could be absorbed by the intestine in an active form and promote somatic growth.

  12. [Selectivity of zooplankton and trophic overlap between size Menidia humboldtiana fish (Atheriniformes: Atherinopsidae) in the reservoir Danxhó, Mexico].

    Science.gov (United States)

    Merino, Regina Sánchez; Benítez, Miriam Y Fermín; Estrada, Angélica Mendoza

    2009-01-01

    The Menidia humboldtiana silverside is considered one of the most important species in fisheries in some states of Mexico. Knowing the choice that this species exercises over its food gives us an understanding of the behavior of zooplankton in presence of zooplanktonic fish, and tells us if the silverside choose amongst bigger prey fish, and if there is competition for food between the native and introduced fish in the reservoir. The purpose of this study was to determine if M. humboldtiana selects its food, and in which genera, and to establish whether there was an overlap in the diet of the different sizes of silverside. The fish were catched with a 88 mm mesh net, in six sampling points during one year, from Danxh6 (19 degrees 5'17" - 53'46" N, 99 degrees 32'42" - 35'40" W) reservoir. Samples of filtered zooplankton were also taken with a 125 micron net. The analysis of stomach contents was carried out in fish grouped by regular size intervals during each season of the year, using the volumetric method and Chesson's selectivity coefficient. To evaluate the trophic overlap between the different size groups, the Morisita index, modified by Horn, was used. The zooplankton community was represented by twelve genera: Mastigodiaptomus and Cyclops (Copepoda); Bosmina, Diaphanosoma, Daphnia, Ceriodaphnia, Moina, Alonopsis and Camptocercus, (Cladocera); Asplanchna, Conochillus and Filinia (Rotifera). Mastigodiaptomus was the most abundant throughout the year. The silverside consumed only four genera: Bosmina, Mastigodiaptomus, Daphnia and Ceriodaphnia; the group measuring 5 to 8.9 cm consumed a high percentage of Bosmina, Mastigodiaptomus and Daphnia, and a lesser percentage of Ceriodaphnia. The larger fish (9 to 10.9 cm) consumed only Mastigodiaptomus and Daphnia. In accordance with the selectivity values, the small and medium size silverside selected their prey, with more intensity on the genera Bosmina and Daphnia, while the bigger fish concentrated on Daphnia and Mastigodiaptomus. During spring, the silverside between 3 to 8.9 cm showed overlap in diet; in summer the bigger size group (7-10.9 cm) showed the overlap. In autumm the overlap ocurred in all sizes, and in winter it was shown only in the medium size fish (5-8.9 cm). PMID:19637700

  13. Populations of Odontesthes (Teleostei: Atheriniformes) in the Andean region of Southern South America: body shape and hybrid individuals

    OpenAIRE

    Cecilia Conte-Grand; Julie Sommer; Guillermo Ortí; Víctor Cussac

    2015-01-01

    The original distribution area of the Patagonian 'pejerrey' Odontesthes hatcheri has been subjected to the introduction of a related species; the Bonaerensean 'pejerrey' Odontesthes bonariensis. This species currently coexists with O. hatcheri in lakes and reservoirs, and can interbreed and produce fertile hybrid offspring. The purposes of this study were; a) the extensive sampling of Patagonian and Andean-Cuyan populations of pejerrey, b) the species identification according to taxonomic key...

  14. Populations of Odontesthes (Teleostei: Atheriniformes in the Andean region of Southern South America: body shape and hybrid individuals

    Directory of Open Access Journals (Sweden)

    Cecilia Conte-Grand

    2015-03-01

    Full Text Available The original distribution area of the Patagonian 'pejerrey' Odontesthes hatcheri has been subjected to the introduction of a related species; the Bonaerensean 'pejerrey' Odontesthes bonariensis. This species currently coexists with O. hatcheri in lakes and reservoirs, and can interbreed and produce fertile hybrid offspring. The purposes of this study were; a the extensive sampling of Patagonian and Andean-Cuyan populations of pejerrey, b the species identification according to taxonomic key, c validation of taxonomic results on the basis of mitochondrial DNA composition, and d applying morphometric analysis to explore the effects of hybridization and environmental conditions on body shape. Cytochrome b sequence analysis showed a high degree of genetic divergence between species and low intraspecific variation in O. hatcheri. Geometric Morphometric Analyses detected shape differences in agreement with diagnostic characteristics of each species. Putative hybrids exhibiting intermediate diagnostic characteristics were identified by Geometric Morphometric Analysis. Significant regressions between body shape and total phosphorus and altitude were found, suggesting a dependence on trophic web structure. This multi-level approach suggests the introgression of O. bonariensis into several O. hatcheri populations throughout Patagonia. Managers should take this into account when considering further exotic introductions into regions where non-native fishes have not yet become established.

  15. Modelos nulos en interacciones biológicas, una propuesta: depredación en chirostoma riojai-zooplancton

    Directory of Open Access Journals (Sweden)

    Octavio M. Vilchis

    2000-01-01

    Full Text Available Se muestra una propuesta de construcción rápida y confiable de los modelos, a partir de una prueba de bondad de ajuste y una de "G" con el fin de apreciar diferencias significativas. Se analiza un estudio de caso que presenta un patrón ecológico (depredación conocido, entre un pez y sus presas.

  16. Evaluation of Melanotaenia duboulayi (Atheriniformes: Melanotaeniidae), Hypseleotris galli (Perciformes: Eleotridae), and larvicide VectoLex WG (Bacillus sphaericus) for integrated control of Culex annulirostris.

    Science.gov (United States)

    Hurst, Timothy P; Brown, Michael D; Kay, Brian H; Ryan, Peter A

    2006-09-01

    Australian freshwater fish species Melanotaenia duboulayi and Hypseleotris galii were selected for a small plot field evaluation of an integrated pest management strategy using native fish and VectoLex WG (Bacillus sphaericus) for the control of Culex annulirostris Skuse, the principal freshwater vector of arbovirus Ross River virus in Australia. When tested alone, the level of control afforded by M. duboulayi and H. galii was highly dependent on the prerelease density of mosquito larvae; and even when stocking rates as high as 10 g per pond (>30 kg/ha) were used, larval abundance was too high to attain adequate control from fish alone. In contrast, treatment with VectoLex WG at 500 g/ha resulted in 100% mortality of Cx. annulirostris immatures, but no residual activity was evident. The delayed reduction of Cx. annulirostris immatures in ponds stocked with fish alone, and the recolonization by Cx. annulirostris in ponds after treatment with B. sphaericus, did not occur when both treatments were combined.

  17. Importancia de los lípidos en la reproducción y ontogenia del pez blanco de Pátzcuaro (Chirostoma estor estor)

    OpenAIRE

    Aparicio, B.

    2004-01-01

    Para producir larvas de peces con buenos rendimientos, se deben conocer los requerimientos nutricionales de la especie, particularmente en los primeros estadios larvarios. Además, se sabe que la nutrición de los reproductores influye directamente en la calidad de las larvas debido, principalmente, a la cantidad y calidad de lípidos que son transferidos desde la gónada hacia los huevos. El objetivo de este trabajo fue analizar la composición de lípidos en huevos, embriones y larvas de pez blan...

  18. Estrutura populacional de Poecilia vivípara Bloch & Schneider, 1801 (Atheriniformes, Poeciliidae do rio Ceará-Mirim - Rio Grande do Norte Populational structure of Poecilia vivipara Block & Schneider, 1801 (Atheriniformes, Poeciliidae of Ceará-Mirim river, State of Rio Grande do Norte

    Directory of Open Access Journals (Sweden)

    Renata Swany Soares Nascimento

    2000-05-01

    Full Text Available Com o propósito de elucidar aspectos da estrutura populacional de Poecilia vivipara do rio Ceará-Mirim, município de Poço Branco, Rio Grande do Norte, foram capturados 3.390 exemplares em coletas mensais, no período de junho de 1995 a maio de 1997, utilizando-se tarrafas e peneiras. A partir dos resultados obtidos, constatou-se que as fêmeas, em relação aos machos, predominaram na proporção de 8:1, considerando-se as análises total e sazonal. No que se refere à distribuição por classes de comprimento para os sexos separados, observou-se uma maior amplitude de comprimento das fêmeas em relação aos machos e ainda uma ausência de diferenças entre as estações chuvosa e seca. De acordo com os valores obtidos para o &Teta; (3,86, verificou-se, para a espécie, um crescimento do tipo alométrico positivo. Quanto à influência dos fatores abióticos, fotoperíodo, pluviosidade, temperatura e nível do rio, relacionados aos aspectos da estrutura populacional, não foram verificados resultados significativos que a confirmassemWith the aim of clarifying aspects of the populational structure of Poecilia vivipara in the Ceará-Mirim river, State of Rio Grande do Norte, a total of 3,390 specimens were captured in monthly collections June 1995 trough May 1997, using nets and sieves. Results showed that females, prevailed in the proportion of 8:1, in the whole period as well as seasonaly. The total length classes distribution for separate sexes indicated that females reaches greatest lengths than males with no difference between dry and rainy seasons. The species growth is of the alometric positive type as suggested by the &Teta; value (3,86. No correlation between abiotic factors (photoperiod duration, rainfall, temperature and river water level and the population structure was found

  19. Estrutura da população e aspectos reprodutivos do peixe-rei Atherinella brasiliensis (Quoy & Gaimard) (Atheriniformes, Atherinopsidae) em áreas rasas do complexo estuarino de Paranaguá, Paraná, Brasil Structure of the population and reproductive aspects of silverside Atherinella brasiliensis (Quoy & Gaimard) (Atheriniformes, Atherinopsidae) in shallow areas of the estuarine complex Paranaguá, Paraná, Brazil

    OpenAIRE

    Luís F. Fávaro; Elton C. de Oliveira; Nelsy F. Verani

    2007-01-01

    A estrutura populacional e aspectos reprodutivos de Atherinella brasiliensis (Quoy & Gaimard, 1825) foram analisados mensalmente de maio de 2000 a abril de 2001, em oito pontos de ambientes rasos do eixo norte-sul do complexo estuarino de Paranaguá. As análises ambientais das variáveis pH, oxigênio dissolvido, transparência e salinidade da água sugerem a existência de um gradiente ambiental crescente no sentido norte-sul do estuário. A temperatura da água evidenciou a variação temporal no sis...

  20. Estrutura da população e aspectos reprodutivos do peixe-rei Atherinella brasiliensis (Quoy & Gaimard (Atheriniformes, Atherinopsidae em áreas rasas do complexo estuarino de Paranaguá, Paraná, Brasil Structure of the population and reproductive aspects of silverside Atherinella brasiliensis (Quoy & Gaimard (Atheriniformes, Atherinopsidae in shallow areas of the estuarine complex Paranaguá, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Luís F. Fávaro

    2007-12-01

    Full Text Available A estrutura populacional e aspectos reprodutivos de Atherinella brasiliensis (Quoy & Gaimard, 1825 foram analisados mensalmente de maio de 2000 a abril de 2001, em oito pontos de ambientes rasos do eixo norte-sul do complexo estuarino de Paranaguá. As análises ambientais das variáveis pH, oxigênio dissolvido, transparência e salinidade da água sugerem a existência de um gradiente ambiental crescente no sentido norte-sul do estuário. A temperatura da água evidenciou a variação temporal no sistema estudado, mostrando-se intimamente relacionado com o processo reprodutivo. O pico de atividade reprodutiva foi determinado para fêmeas e machos, respectivamente, nos meses de outubro e setembro, período em que se verificou a proporção de duas fêmeas para um macho. O predomínio de indivíduos jovens no estuário ocorreu no final da primavera e durante o verão, após o período reprodutivo. As análises sazonais de comprimento e de massa corporal sugerem a existência de um padrão cíclico de crescimento ao longo do ano, o qual reflete o período reprodutivo e o recrutamento. Assim, conclui-se que A. brasiliensis é uma espécie estuarina residente, mostrando-se amplamente distribuída nas áreas rasas estuarinas, podendo ser considerada chave em avaliações de impacto ambiental e/ou em ações de planos de manejo e conservação em ambientes estuarinos.The population structure and reproductive aspects of Atherinella brasiliensis (Quoy & Gaimard, 1825 had been analyzed monthly from May 2000 to April 2001 in eight points of shallow areas of the estuarine complex Paranaguá. The environment analyzes of the parameters pH, dissolved oxygen, transparency and salinity of the water suggest the existence of an increasing environment gradient in the direction North-South highway of the estuary. The temperature of the water evidenced the seasonal variation in the studied system, revealing related with the reproductive process. The peak of reproductive activity was determined for females and male, respectively, in the months of October and September, period where if it verified the ratio of two females for a male. The predominance of young individuals in the estuary occurred in the end of the spring and during the summer, after the reproductive period. The seasonal analyses of length and mass suggest the existence of a cyclical standard of growth to the long of the year, which reflects the reproductive period and the entrance of young individuals in the environment. Thus, it is concluded that A. brasiliensis is a resident estuarine species, revealing widely distributed in the estuarine shallow areas, being able to be considered key in evaluations of environmental impact and/or action of handling plans and conservation in estuarine environments.

  1. Spinitectus osorioi (Nematoda: Cystidicolidae) in the Mexican endemic fish Atherinella alvarezi (Atherinopsidae) from the Atlantic River drainage system in Chiapas, Southern Mexico

    OpenAIRE

    František Moravec; Guillermo Salgado-Maldonado; Juan M Caspeta-Mandujano

    2010-01-01

    Specimens of Spinitectus osorioi Choudhury and Pérez-Ponce de León, an intestinal nematode species previously considered to be specific to Chirostoma spp and endemic to some lakes in the Pacific drainage in Michoacán, were collected from the freshwater fish Atherinella alvarezi (Díaz-Pardo) (Atherinopsidae) of the Michol River near Palenque, Chiapas, Southern Mexico, which belongs to the Atlantic drainage system. Studies using light and scanning electron microscopy revealed some taxonomically...

  2. Trophic interactions among sympatric zooplanktivorous fish species in volume change conditions in a large, shallow, tropical lake

    OpenAIRE

    Rodrigo Moncayo-Estrada; Owen T. Lind; Carlos Escalera-Gallardo

    2011-01-01

    Significant reductions in the water volume of shallow lakes impose a restriction on species segregation promoting more interactions in the trophic relationships. The diets of three closely related zooplanktivorous silversides belonging to the Atherinopsidae species flock of lake Chapala , Mexico, were analyzed at two sites (Chirostoma jordani, C. labarcae, and C. consocium). Diets were described in critical shallow (August 2000) and volume recovery conditions (August 2005). Diets included mai...

  3. Espectro trófico del bagre Ictalurus punctatus (Silurifomes: Ictaluridae), en la presa Lázaro Cárdenas, Indé, Durango, México Trophic spectrum of the catfish Ictalurus punctatus (Siluriformes: Ictaluridae), in the Lázaro Cárdenas reservoir, Indé, Durango, Mexico

    OpenAIRE

    Gabriel Fernando Cardoza Martínez; José Luis Estrada Rodríguez; Fernando Alonzo Rojo; Carmen Leticia Mar Tovar; Frances Gelwick

    2011-01-01

    Se analizó el contenido de 240 estómagos de Ictalurus punctatus (Rafinesque, 1818), colectados de 2006 a 2007, con el objetivo de determinar su espectro trófico, su variación por talla y época climática. Los contenidos estomacales se analizaron en laboratorio y los organismos se determinaron hasta nivel de orden. Los datos obtenidos fueron analizados por métodos cuantitativos y cualitativos. Los órdenes más frecuentes fueron Perciformes y Atheriniformes que corresponden a peces forraje, así c...

  4. Espectro trófico del bagre Ictalurus punctatus (Silurifomes: Ictaluridae, en la presa Lázaro Cárdenas, Indé, Durango, México Trophic spectrum of the catfish Ictalurus punctatus (Siluriformes: Ictaluridae, in the Lázaro Cárdenas reservoir, Indé, Durango, Mexico

    Directory of Open Access Journals (Sweden)

    Gabriel Fernando Cardoza Martínez

    2011-08-01

    Full Text Available Se analizó el contenido de 240 estómagos de Ictalurus punctatus (Rafinesque, 1818, colectados de 2006 a 2007, con el objetivo de determinar su espectro trófico, su variación por talla y época climática. Los contenidos estomacales se analizaron en laboratorio y los organismos se determinaron hasta nivel de orden. Los datos obtenidos fueron analizados por métodos cuantitativos y cualitativos. Los órdenes más frecuentes fueron Perciformes y Atheriniformes que corresponden a peces forraje, así como algas verdes del orden Charales. Además, se encontraron otros siete órdenes de invertebrados: Schizodonta, Odonata, Himenoptera, Orthoptera, Hemiptera, Homoptera y Scorpionida, además de dos órdenes de plantas: Poales y Fabales. El orden Perciforme constituyó casi la mitad del total del peso del contenido estomacal, seguido por los órdenes Atheriniforme y Charales. En las estaciones de verano e invierno se presentó el mayor número de estómagos vacíos, mientras que en primavera se encontró el mayor número de estómagos llenos. La cantidad de alimento ingerida en la estación de invierno fue significativamente menor que en las demás estaciones. El principal alimento en primavera, verano y otoño, fueron los peces, mientras que en invierno hubo mayor preferencia por las algas.Having the objective of determining their trophic spectrum and their variations within a year, the contents of 240 stomachs of Ictalurus punctatus (Rafinesque, 1818 were analyzed from 2006 to 2007. The items of the stomach contents were determined to the order level. The data was analyzed by different quantitative and qualitative methods. The most frequent orders were Perciforms and Atheriniforms corresponding to forage fish, along with green algae of the Charales order. Also, seven orders of invertebrates were found: Schizodonta, Odonata, Himenoptera, Orthoptera, Hemiptera, Homoptera and Scorpionida, and two orders of plants: Poales and Fabales. The Perciform

  5. Complexities in pyroxene compositions derived from absorption band centers: Examples from Apollo samples, HED meteorites, synthetic pure pyroxenes, and remote sensing data

    Science.gov (United States)

    Moriarty, D. P.; Pieters, C. M.

    2016-02-01

    We reexamine the relationship between pyroxene composition and near-infrared absorption bands, integrating measurements of diverse natural and synthetic samples. We test an algorithm (PLC) involving a two-part linear continuum removal and parabolic fits to the 1 and 2 μm bands—a computationally simple approach which can easily be automated and applied to remote sensing data. Employing a suite of synthetic pure pyroxenes, the PLC technique is shown to derive similar band centers to the modified Gaussian model. PLC analyses are extended to natural pyroxene-bearing materials, including (1) bulk lunar basalts and pyroxene separates, (2) diverse lunar soils, and (3) HED meteorites. For natural pyroxenes, the relationship between composition and absorption band center differs from that of synthetic pyroxenes. These differences arise from complexities inherent in natural materials such as exsolution, zoning, mixing, and space weathering. For these reasons, band center measurements of natural pyroxene-bearing materials are compositionally nonunique and could represent three distinct scenarios (1) pyroxene with a narrow compositional range, (2) complexly zoned pyroxene grains, or (3) a mixture of multiple pyroxene (or nonpyroxene) components. Therefore, a universal quantitative relationship between band centers and pyroxene composition cannot be uniquely derived for natural pyroxene-bearing materials without additional geologic context. Nevertheless, useful relative relationships between composition and band center persist in most cases. These relationships are used to interpret M3 data from the Humboldtianum Basin. Four distinct compositional units are identified (1) Mare Humboldtianum basalts, (2) distinct outer basalts, (3) low-Ca pyroxene-bearing materials, and (4) feldspathic materials.

  6. Spinitectus osorioi (Nematoda: Cystidicolidae in the Mexican endemic fish Atherinella alvarezi (Atherinopsidae from the Atlantic River drainage system in Chiapas, Southern Mexico

    Directory of Open Access Journals (Sweden)

    František Moravec

    2010-02-01

    Full Text Available Specimens of Spinitectus osorioi Choudhury and Pérez-Ponce de León, an intestinal nematode species previously considered to be specific to Chirostoma spp and endemic to some lakes in the Pacific drainage in Michoacán, were collected from the freshwater fish Atherinella alvarezi (Díaz-Pardo (Atherinopsidae of the Michol River near Palenque, Chiapas, Southern Mexico, which belongs to the Atlantic drainage system. Studies using light and scanning electron microscopy revealed some taxonomically important, previously unreported or erroneously reported features of S. osorioi, such as the location of the vulva, the actual number and distribution of postanal papillae and phasmids and the presence of a short median cuticular ridge anterior to the cloacal opening (in addition to two long subventral ridges. The recorded somewhat shorter spicules (420-465 and 105-111 μm and mostly smaller eggs (33-36 × 18-20 μm as compared to the original species description may be due to a different type of host, geographical region or generally smaller body measurements of these specimens. These biometrical differences are considered to be within the limits of the intraspecific variability of S. osorioi. A key to species of Spinitectus parasitizing freshwater fishes in Mexico is provided.

  7. Trophic interactions among sympatric zooplanktivorous fish species in volume change conditions in a large, shallow, tropical lake

    Directory of Open Access Journals (Sweden)

    Rodrigo Moncayo-Estrada

    2011-03-01

    Full Text Available Significant reductions in the water volume of shallow lakes impose a restriction on species segregation promoting more interactions in the trophic relationships. The diets of three closely related zooplanktivorous silversides belonging to the Atherinopsidae species flock of lake Chapala , Mexico, were analyzed at two sites (Chirostoma jordani, C. labarcae, and C. consocium. Diets were described in critical shallow (August 2000 and volume recovery conditions (August 2005. Diets included mainly cladocerans (Bosmina, Ceriodaphnia, and Daphnia and copepods (Cyclops. A significant difference in diets was detected when comparing years (MRPP analysis, A = 0.22, p La reducción significativa en el volumen de agua de los lagos someros impone una restricción en la segregación de las especies y promueve una mayor interacción en las relaciones tróficas. Se analizó la dieta de tres especies cercanamente emparentadas de zooplanctívoros pertenecientes al flock de Aterinópsidos del lago de Chapala en dos sitios (Chirostoma jordani, C. labarcae y C. consocium. Las dieta fue descrita en una condición somera crítica (Agosto 2000 y en una condición de recuperación del lago (Agosto 2005. En la dieta se incluyen principalmente cladóceros (Bosmina, Ceriodaphnia y Daphnia y copépodos (Cyclops. Se detectó una diferencia significativa en la dieta cuando se comparan los años (análisis MRPP, A = 0.22, p < 0.0001 y los sitios en los diferentes años (análisis MRPP, A = 0.17, p = 0.004. De acuerdo a los valores promedio de amplitud de nicho, las especies fueron clasificadas como especialistas y consumidores intermediarios. En condiciones someras, el pequeño intervalo de la amplitud de nicho (1.72 a 3.64 y los altos valores del traslape de nicho (D = 0.64, L = 8.62 indicaron un alto potencial para una interacción explotativa inter-específica. Cuando el lago se recupera en su volumen, un incremento en el intervalo de amplitud de nicho (1.04 a 4.96 y los

  8. Lunar Impact Basins: Stratigraphy, Sequence and Ages from Superposed Impact Crater Populations Measured from Lunar Orbiter Laser Altimeter (LOLA) Data

    Science.gov (United States)

    Fassett, C. I.; Head, J. W.; Kadish, S. J.; Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

    2012-01-01

    Impact basin formation is a fundamental process in the evolution of the Moon and records the history of impactors in the early solar system. In order to assess the stratigraphy, sequence, and ages of impact basins and the impactor population as a function of time, we have used topography from the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO) to measure the superposed impact crater size-frequency distributions for 30 lunar basins (D = 300 km). These data generally support the widely used Wilhelms sequence of lunar basins, although we find significantly higher densities of superposed craters on many lunar basins than derived by Wilhelms (50% higher densities). Our data also provide new insight into the timing of the transition between distinct crater populations characteristic of ancient and young lunar terrains. The transition from a lunar impact flux dominated by Population 1 to Population 2 occurred before the mid-Nectarian. This is before the end of the period of rapid cratering, and potentially before the end of the hypothesized Late Heavy Bombardment. LOLA-derived crater densities also suggest that many Pre-Nectarian basins, such as South Pole-Aitken, have been cratered to saturation equilibrium. Finally, both crater counts and stratigraphic observations based on LOLA data are applicable to specific basin stratigraphic problems of interest; for example, using these data, we suggest that Serenitatis is older than Nectaris, and Humboldtianum is younger than Crisium. Sample return missions to specific basins can anchor these measurements to a Pre-Imbrian absolute chronology.