Mairin Lemus - Academia.edu (original) (raw)
Papers by Mairin Lemus
Ciencias Marinas, Jun 15, 2006
Revista De Biologia Tropical, Dec 1, 2000
The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprino... more The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprinodon dearborni was determined in two coastal lagoons of Sucre State, Venezuela. Chacopata lagoon is hyper saline while Los Patos lagoon is hypo saline and receives significant wastewater from Cumaná city. Water, sediment and fish samples were collected in February 1998. In the laboratory, samples underwent acid digestion and were analyzed by atomic absorption spectophotometry. The mean values of the metals in C. dearborni from the Chacopata lagoon were: 159.26 +/- 210.68 microg/g for Cu, 44.71 +/- 45.58 microg/g for Cd, and 9.31 +/- 23.34 microg/g for Pb, while for Los Patos lagoon the mean values were: 64.88 +/- 16.30, 19.48 +/- 5.81 and 22.85 +/- 20.00, respectively. In the water column, the metal concentration ranges were: 2.3-11.6, 3.9-5.4 and 21-32 mg/l for copper, cadmium and lead, respectively. These results suggest that metal levels in sediment, water column and organisms in both lagoons do not differ, except for lead, even though only Los Patos receives waste water.
PubMed, Aug 23, 2002
Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furni... more Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furnieri were examined in 256 male and female specimens, between 28.7 and 54.3 cm total length, collected around Morro Puerto Santo, in northeast Sucre State, Venezuela (10 degrees 45'00" N-63 degrees 8'0" W), from May 1989 to April 1990. Micropogonias furnieri has a small ventral mouth; protrusible premaxillary and dentary; first branchial arches with 21 to 27 gill rakers, generally 24 to 25; and 7 to 11 pyloric caecae. The index of vacuity was low, with mean value of 7.00%. The mean intestinal index was 0.72, indicative of carnivorous species. Analysis of frequency of occurrence, indicates preference for crustaceans (45.70%), mainly crabs (34.90%), followed by polychaetes (28.00%), fishes (11.41%) and occasionally mollusks and echinoderms (4.0 and 3.9%, respectively). The diet of this species did not vary with sex.
Revista De Biologia Tropical, Dec 1, 2000
Benthic test species used in toxicity assays are the best indicators of sediment toxicity because... more Benthic test species used in toxicity assays are the best indicators of sediment toxicity because they live in direct contact with sediments and the water column. Mercury chloride is one the most toxic metallic salts. Its strong affinity for particles explains the high Hg content found in benthic populations. The genus Emerita is abundantly found in Venezuelan coasts and is a good bioaccumulator of pollutants, but the toxicological assays performend on this genus are scarce. The present experimental test reports on the distribution of mercury in the water column and sediment, using static bioassay in short term (24 hr) and the ability of Emerita portoricensis to bioconcentrate mercury under experimental conditions. Our results suggest that the Hg transference from water to sediment is enhanced in the presence of Emerita. The kinetic uptake of Hg in Emerita portoricensis shows a mechanism of rapid absorption reaching high metal concentrations in short exposure times.
Revista De Biologia Tropical, Jun 14, 2017
Zenodo (CERN European Organization for Nuclear Research), Jul 7, 2015
DOAJ (DOAJ: Directory of Open Access Journals), Mar 1, 2012
The biologist, 2014
espanolLa salinidad en las zonas costeras es uno de los parametros ambientales mas variables debi... more espanolLa salinidad en las zonas costeras es uno de los parametros ambientales mas variables debido a los aportes de aguas continentales y sus efectos son importantes en los procesos osmoregulatorios de los invertebrados, particularmente los sesiles, como los bivalvos. Se conoce muy poco, acerca de los riesgos de la exposicion prolongada abaja concentracion de salinidad en Perna viridis y sus efectos sobre la condicion fisiologica. En este estudio, P. viridis, una especie de importante en maricultura, fue expuesta a diferentes salinidades de 36, 16 y 12 ups, que se redujeron en 2 ups cada dos dias hasta alcanzar ocho semanas, en las salinidades experimentales. Durante el periodo experimental se mantuvo el fotoperiodo en 12/12 y la temperatura de 25±1,5°C.Los organismos fueron alimentados diariamente con una mezcla de los monocultivos de microalgas (alrededor de 30000 celulas·mL-1) de Chaetoceros gracilis y Tetraselmis chuii. En todas las muestras se determino pH, iones intra y extra...
Benthic organisms have been proposed as good indicators of disturbance in marine environments, pa... more Benthic organisms have been proposed as good indicators of disturbance in marine environments, particularly because most toxins fall to the bottom of the sea affecting benthic communities. A non-invasive method for collecting coelomocytes was developed using the marine polychaete Eurythoe complanata with potential applications in xenobiotic toxicology. The extrusion method used produced the expulsion of 95% of the coelomic fluid, showing a greater efficiency than the puncture method in Lumbricus terrestris with regard to the total number of coelomocytes and cellular viability. The total coelomocyte count by this method was 6 -1 6 -1 2.6 x 10 cells·mL vs 1.4 x 10 cells·mL for the puncture method. The results indicate that coelomocyte numbers completely recover at 20 days after extrusion, using the total cell count, cell viability and differential count. This method was developed to study immunotoxicity of xenobiotics at the sediment-water interface of marine environments.
Revista chilena de obstetricia y ginecología, 1983
Boletín del Instituto Oceanográfico de la Universidad de Oriente, 1991
Caribbean Journal of Science, 1999
Revista de Salud Ambiental, 2015
Se evaluaron las concentraciones de metales Fe, Zn, Cu, Cr, Cd y Ni y su relacion con marcadores ... more Se evaluaron las concentraciones de metales Fe, Zn, Cu, Cr, Cd y Ni y su relacion con marcadores de estres oxidativo en 50 fumadores cronicos de ambos generos (30 y 84 anos). Los fumadores se dividieron en dos grupos: 25 fumadores de 1-5 cigarrillos/dia (cig/dia) y 25 fumadores de mas de 6 cig/dia. Los niveles de metales en sangre total y en orina fueron determinados por espectrofotometria de emision atomica con plasma inductivamente acoplado (ICPOES). Se realizaron determinaciones hematologicas y bioquimicas de proteinas totales, fraccionadas y de tioles totales. Los fumadores presentaron mayores concentraciones de Fe en sangre independientemente del numero de cigarrillos fumados y menores concentraciones de Zn, Cr y Ni. No se observaron diferencias en las concentraciones de Cu en sangre. El Cd en fumadores estuvo entre 5,0-10,0 μg/L y en no-fumadores entre 0,0-5,0 μg/L. No se observaron diferencias signi cativas en las concentraciones de hemoglobina, hematocrito y la hemoglobina c...
Ciencias Marinas, 2009
Mercury levels were determined in green mussels, Perna viridis, from two localities of Sucre Stat... more Mercury levels were determined in green mussels, Perna viridis, from two localities of Sucre State (Venezuela): Chacopata and Río Caribe. Specimens were captured in the intertidal zone from February to December 2003. They presented anteroposterior lengths ranging from 18 to 113 mm and were classified, according to their sexual maturity, as juveniles or adults. Mercury was determined by flame atomic absorption spectrophotometry and the method of analysis was validated using certified standards. Seasonal variations were significant at both sites. Highest mercury concentrations in the Chacopata specimens were recorded during February (mean value of 0.432 ± 0.472 µg g–1 d.w.) and in the Río Caribe specimens during April (mean value of 1.129 ± 0.763 µg g–1 d.w.). No relation between mercury levels and sexual maturity was found at Chacopata, but a relation was observed at Río Caribe. Immature organisms showed the highest concentrations (0.471 ± 0.679 and 0.688 ± 0.894 µg g–1 d.w. for male...
Revista De Biologia Tropical, 2001
Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furni... more Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furnieri were examined in 256 male and female specimens, between 28.7 and 54.3 cm total length, collected around Morro Puerto Santo, in northeast Sucre State, Venezuela (10 degrees 45'00" N-63 degrees 8'0" W), from May 1989 to April 1990. Micropogonias furnieri has a small ventral mouth; protrusible premaxillary and dentary; first branchial arches with 21 to 27 gill rakers, generally 24 to 25; and 7 to 11 pyloric caecae. The index of vacuity was low, with mean value of 7.00%. The mean intestinal index was 0.72, indicative of carnivorous species. Analysis of frequency of occurrence, indicates preference for crustaceans (45.70%), mainly crabs (34.90%), followed by polychaetes (28.00%), fishes (11.41%) and occasionally mollusks and echinoderms (4.0 and 3.9%, respectively). The diet of this species did not vary with sex.
The Biologist
Se evaluaron los niveles de metales pesados en ejemplares machos y hembras del bivalvo Atrina sem... more Se evaluaron los niveles de metales pesados en ejemplares machos y hembras del bivalvo Atrina seminuda (Lamarck, 1819). Los organismos fueron colectados en la localidad de Guayacán, estado Sucre, Venezuela. Las concentraciones Cu, Cd, Cr, Ni, Pb, Fe y Zn se determinaron en los tejidos: gónada (G), músculo (M), hepatopáncreas (H) y resto (R) mediante espectroscopia de emisión de plasma de acoplamiento inductivo (ICP-OES). El índice gonadosomático (IGS) presentó diferencias significativas, mostrando su valor más alto en febrero (19,67 ± 0,43) y el menor en junio (13,26 ± 0,43). Las concentraciones de metales presentaron diferencias significativas entre los tejidos analizados; observándose en general una mayor acumulación de metales en el H y el R. Se mostraron variaciones mensuales significativas de los metales en los tejidos con las mayores concentraciones de Cu, Cd, Cr, Ni y Zn entre los meses de abril y mayo. El análisis de ACP determina que IGS está asociado a la incorporación de ...
Revista De Biologia Tropical, 2000
Ciencias Marinas, Jun 15, 2006
Revista De Biologia Tropical, Dec 1, 2000
The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprino... more The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprinodon dearborni was determined in two coastal lagoons of Sucre State, Venezuela. Chacopata lagoon is hyper saline while Los Patos lagoon is hypo saline and receives significant wastewater from Cumaná city. Water, sediment and fish samples were collected in February 1998. In the laboratory, samples underwent acid digestion and were analyzed by atomic absorption spectophotometry. The mean values of the metals in C. dearborni from the Chacopata lagoon were: 159.26 +/- 210.68 microg/g for Cu, 44.71 +/- 45.58 microg/g for Cd, and 9.31 +/- 23.34 microg/g for Pb, while for Los Patos lagoon the mean values were: 64.88 +/- 16.30, 19.48 +/- 5.81 and 22.85 +/- 20.00, respectively. In the water column, the metal concentration ranges were: 2.3-11.6, 3.9-5.4 and 21-32 mg/l for copper, cadmium and lead, respectively. These results suggest that metal levels in sediment, water column and organisms in both lagoons do not differ, except for lead, even though only Los Patos receives waste water.
PubMed, Aug 23, 2002
Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furni... more Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furnieri were examined in 256 male and female specimens, between 28.7 and 54.3 cm total length, collected around Morro Puerto Santo, in northeast Sucre State, Venezuela (10 degrees 45'00" N-63 degrees 8'0" W), from May 1989 to April 1990. Micropogonias furnieri has a small ventral mouth; protrusible premaxillary and dentary; first branchial arches with 21 to 27 gill rakers, generally 24 to 25; and 7 to 11 pyloric caecae. The index of vacuity was low, with mean value of 7.00%. The mean intestinal index was 0.72, indicative of carnivorous species. Analysis of frequency of occurrence, indicates preference for crustaceans (45.70%), mainly crabs (34.90%), followed by polychaetes (28.00%), fishes (11.41%) and occasionally mollusks and echinoderms (4.0 and 3.9%, respectively). The diet of this species did not vary with sex.
Revista De Biologia Tropical, Dec 1, 2000
Benthic test species used in toxicity assays are the best indicators of sediment toxicity because... more Benthic test species used in toxicity assays are the best indicators of sediment toxicity because they live in direct contact with sediments and the water column. Mercury chloride is one the most toxic metallic salts. Its strong affinity for particles explains the high Hg content found in benthic populations. The genus Emerita is abundantly found in Venezuelan coasts and is a good bioaccumulator of pollutants, but the toxicological assays performend on this genus are scarce. The present experimental test reports on the distribution of mercury in the water column and sediment, using static bioassay in short term (24 hr) and the ability of Emerita portoricensis to bioconcentrate mercury under experimental conditions. Our results suggest that the Hg transference from water to sediment is enhanced in the presence of Emerita. The kinetic uptake of Hg in Emerita portoricensis shows a mechanism of rapid absorption reaching high metal concentrations in short exposure times.
Revista De Biologia Tropical, Jun 14, 2017
Zenodo (CERN European Organization for Nuclear Research), Jul 7, 2015
DOAJ (DOAJ: Directory of Open Access Journals), Mar 1, 2012
The biologist, 2014
espanolLa salinidad en las zonas costeras es uno de los parametros ambientales mas variables debi... more espanolLa salinidad en las zonas costeras es uno de los parametros ambientales mas variables debido a los aportes de aguas continentales y sus efectos son importantes en los procesos osmoregulatorios de los invertebrados, particularmente los sesiles, como los bivalvos. Se conoce muy poco, acerca de los riesgos de la exposicion prolongada abaja concentracion de salinidad en Perna viridis y sus efectos sobre la condicion fisiologica. En este estudio, P. viridis, una especie de importante en maricultura, fue expuesta a diferentes salinidades de 36, 16 y 12 ups, que se redujeron en 2 ups cada dos dias hasta alcanzar ocho semanas, en las salinidades experimentales. Durante el periodo experimental se mantuvo el fotoperiodo en 12/12 y la temperatura de 25±1,5°C.Los organismos fueron alimentados diariamente con una mezcla de los monocultivos de microalgas (alrededor de 30000 celulas·mL-1) de Chaetoceros gracilis y Tetraselmis chuii. En todas las muestras se determino pH, iones intra y extra...
Benthic organisms have been proposed as good indicators of disturbance in marine environments, pa... more Benthic organisms have been proposed as good indicators of disturbance in marine environments, particularly because most toxins fall to the bottom of the sea affecting benthic communities. A non-invasive method for collecting coelomocytes was developed using the marine polychaete Eurythoe complanata with potential applications in xenobiotic toxicology. The extrusion method used produced the expulsion of 95% of the coelomic fluid, showing a greater efficiency than the puncture method in Lumbricus terrestris with regard to the total number of coelomocytes and cellular viability. The total coelomocyte count by this method was 6 -1 6 -1 2.6 x 10 cells·mL vs 1.4 x 10 cells·mL for the puncture method. The results indicate that coelomocyte numbers completely recover at 20 days after extrusion, using the total cell count, cell viability and differential count. This method was developed to study immunotoxicity of xenobiotics at the sediment-water interface of marine environments.
Revista chilena de obstetricia y ginecología, 1983
Boletín del Instituto Oceanográfico de la Universidad de Oriente, 1991
Caribbean Journal of Science, 1999
Revista de Salud Ambiental, 2015
Se evaluaron las concentraciones de metales Fe, Zn, Cu, Cr, Cd y Ni y su relacion con marcadores ... more Se evaluaron las concentraciones de metales Fe, Zn, Cu, Cr, Cd y Ni y su relacion con marcadores de estres oxidativo en 50 fumadores cronicos de ambos generos (30 y 84 anos). Los fumadores se dividieron en dos grupos: 25 fumadores de 1-5 cigarrillos/dia (cig/dia) y 25 fumadores de mas de 6 cig/dia. Los niveles de metales en sangre total y en orina fueron determinados por espectrofotometria de emision atomica con plasma inductivamente acoplado (ICPOES). Se realizaron determinaciones hematologicas y bioquimicas de proteinas totales, fraccionadas y de tioles totales. Los fumadores presentaron mayores concentraciones de Fe en sangre independientemente del numero de cigarrillos fumados y menores concentraciones de Zn, Cr y Ni. No se observaron diferencias en las concentraciones de Cu en sangre. El Cd en fumadores estuvo entre 5,0-10,0 μg/L y en no-fumadores entre 0,0-5,0 μg/L. No se observaron diferencias signi cativas en las concentraciones de hemoglobina, hematocrito y la hemoglobina c...
Ciencias Marinas, 2009
Mercury levels were determined in green mussels, Perna viridis, from two localities of Sucre Stat... more Mercury levels were determined in green mussels, Perna viridis, from two localities of Sucre State (Venezuela): Chacopata and Río Caribe. Specimens were captured in the intertidal zone from February to December 2003. They presented anteroposterior lengths ranging from 18 to 113 mm and were classified, according to their sexual maturity, as juveniles or adults. Mercury was determined by flame atomic absorption spectrophotometry and the method of analysis was validated using certified standards. Seasonal variations were significant at both sites. Highest mercury concentrations in the Chacopata specimens were recorded during February (mean value of 0.432 ± 0.472 µg g–1 d.w.) and in the Río Caribe specimens during April (mean value of 1.129 ± 0.763 µg g–1 d.w.). No relation between mercury levels and sexual maturity was found at Chacopata, but a relation was observed at Río Caribe. Immature organisms showed the highest concentrations (0.471 ± 0.679 and 0.688 ± 0.894 µg g–1 d.w. for male...
Revista De Biologia Tropical, 2001
Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furni... more Morphology of the mandibular and pharyngeal region, and the feeding habits of Micropogonias furnieri were examined in 256 male and female specimens, between 28.7 and 54.3 cm total length, collected around Morro Puerto Santo, in northeast Sucre State, Venezuela (10 degrees 45'00" N-63 degrees 8'0" W), from May 1989 to April 1990. Micropogonias furnieri has a small ventral mouth; protrusible premaxillary and dentary; first branchial arches with 21 to 27 gill rakers, generally 24 to 25; and 7 to 11 pyloric caecae. The index of vacuity was low, with mean value of 7.00%. The mean intestinal index was 0.72, indicative of carnivorous species. Analysis of frequency of occurrence, indicates preference for crustaceans (45.70%), mainly crabs (34.90%), followed by polychaetes (28.00%), fishes (11.41%) and occasionally mollusks and echinoderms (4.0 and 3.9%, respectively). The diet of this species did not vary with sex.
The Biologist
Se evaluaron los niveles de metales pesados en ejemplares machos y hembras del bivalvo Atrina sem... more Se evaluaron los niveles de metales pesados en ejemplares machos y hembras del bivalvo Atrina seminuda (Lamarck, 1819). Los organismos fueron colectados en la localidad de Guayacán, estado Sucre, Venezuela. Las concentraciones Cu, Cd, Cr, Ni, Pb, Fe y Zn se determinaron en los tejidos: gónada (G), músculo (M), hepatopáncreas (H) y resto (R) mediante espectroscopia de emisión de plasma de acoplamiento inductivo (ICP-OES). El índice gonadosomático (IGS) presentó diferencias significativas, mostrando su valor más alto en febrero (19,67 ± 0,43) y el menor en junio (13,26 ± 0,43). Las concentraciones de metales presentaron diferencias significativas entre los tejidos analizados; observándose en general una mayor acumulación de metales en el H y el R. Se mostraron variaciones mensuales significativas de los metales en los tejidos con las mayores concentraciones de Cu, Cd, Cr, Ni y Zn entre los meses de abril y mayo. El análisis de ACP determina que IGS está asociado a la incorporación de ...
Revista De Biologia Tropical, 2000