Samuel Narciso - Academia.edu (original) (raw)
Papers by Samuel Narciso
Biological Invasions
The movement of species is among the most serious environmental threats of the new millennium, as... more The movement of species is among the most serious environmental threats of the new millennium, as the transplantation of species beyond their native or historical range has intensified in the last five decades. Traditionally, studies on bioinvasions have focused on species that have been introduced, deliberately or accidentally, to biogeographic regions where they did not previously occur. However, less attention has been given to species movement to novel areas within the same biogeographic region. Our research group, the South America Introduced Molluscs Specialists, analyzed potential cases of native South American mollusc species introduced deliberately or accidentally beyond their natural range within South America. To achieve this, it is key to differentiate between anthropogenic processes and passive responses to environmental conditions. We considered the past and current spatial distribution of species, analyzed known or putative vectors, and discuss the impacts of taxonomic and nomenclatural knowledge. Based on the evidence currently available, we propose different scenarios to explain observed changes in mollusc distributions within South America. Seventeen transplanted mollusc species (TMS) were recognized, considering marine, freshwater, and terrestrial environments. Of the 189 South American ecoregions 31 were occupied by transplanted species, but this proportion varied by environment: 10 of 28 marine ecoregions, 12 of 52 freshwater ecoregions, and 9 of 109 terrestrial ecoregions. The ecoregions with TMS are generally located in the peripheral zones of the continent. Those with the highest number of TMS were the Southern Caribbean (three species) in the marine environment, the Central Andean Pacific Slopes (three species) in the freshwater environment, and the Alto Paraná Atlantic forests (two species) in the terrestrial environment. The number of unintentionally moved TMS is greater than those moved intentionally. The transplantation process is similar to the introduction and settlement process of non-native mollusc species, and so is their impact.
Fundación La Salle de Ciencias Naturales, May 20, 2019
Carmen Teresa Rodríguez y Samuel Elías Narciso-Fejure Resumen. Los ejemplares identificados en el... more Carmen Teresa Rodríguez y Samuel Elías Narciso-Fejure Resumen. Los ejemplares identificados en el presente trabajo fueron colectados manualmente en visitas ocasionales al arrecife coralino de Isla Larga, entre los años 2006, 2007 y 2009, y de forma sistemática sobre el gradiente de profundidad de 0 a 18 m durante los meses de mayo, junio y julio de 2010; a fin de tener un reporte taxonómico de las especies de bivalvos y gasterópodos de la zona. Se identificaron 23 familias dentro del Phylum Mollusca correspondientes a 38 especies de las Clases Bivalvia (21) y Gastropoda (17). Valores similares de riqueza de especies se han registrado en otros arrecifes del Caribe. El número de especies encontradas en un área de muestreo tan pequeña del Parque Nacional San Esteban, sugiere la necesidad de incrementar el esfuerzo de muestreo hacia otros arrecifes del mismo.
FIGURE 6. A, Aphelodoris antillensis. B, Platydoris angustipes. C, Sclerodoris prea. D, Felimare ... more FIGURE 6. A, Aphelodoris antillensis. B, Platydoris angustipes. C, Sclerodoris prea. D, Felimare acriba. E-F, Felimare fregona. G, Felimare kempfi. H, Coryphella dushia. I, Flabellina engeli. J, Flabellina verta. K, Austraeolis catina. L Nanuca sebastiani. M, Berghia creutzbergi. N, Cuthona iris. Ο, Tritoniopsis frydis. Sea s1ugs in their natura1 envirοnment (Gaby Carias).
FIGURE 5. A, Dondice occidentalis. B, Godiva rubrolineata. C, Favorinus auritulus. D, Phidiana ly... more FIGURE 5. A, Dondice occidentalis. B, Godiva rubrolineata. C, Favorinus auritulus. D, Phidiana lynceus. E, Spurilla sargassicola. F, Eubranchus conicla. G, Scyllaea pelagica. H, Doto casandra. I, Chelidonura cubana. J, Aplysia parvula. K, Syphonota geographica. L, Pleurobranchus areolatus. M, Elysia papillosa. N, Thuridilla malaquita. Ο-P, Placida cremoniana. Q, Okenia zoobotryon. I-Q, Sea s1ugs in their natura1 envirοnment (Gaby Carias).
FIGURE 4. A, Bursatella leachii. B, Cadlina rumia. C, Bermudella polycerelloides. D, Doris bovena... more FIGURE 4. A, Bursatella leachii. B, Cadlina rumia. C, Bermudella polycerelloides. D, Doris bovena. E, Polycera odhneri. F, Caribranchus morsomus, ventra1 view. G, Caribranchus morsomus, dοrsa1 view. H, Dendrodoris krebsii. I, Dendrodoris warta (fixed). J, Felimida binza. K, Felimida clenchi. L, Tyrinna evelinae. M, Felimare ruthae. N, Felimare samueli.
FIGURE 3. A, Phyllaplysia engeli. B, Stylocheilus striatus. C, Berthella agassizii. D, Lobiger so... more FIGURE 3. A, Phyllaplysia engeli. B, Stylocheilus striatus. C, Berthella agassizii. D, Lobiger souverbii. E, Oxynoe antillarum. F, Elysia crispata. G, Elysia ornata. H, Elysia flava. I, Elysia tuca. J, Elysia cauze. K, Cyerce habanensis. L, Ercolania fuscata. M, Placida verticilata. N, Costasiella nonatoi. Ο, Cylindrobulla beauii.
Abstract: El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The a... more Abstract: El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The aim of this work was to evaluate the massive bleaching of coral reefs in Puerto Cabello, Venezuela derived from ENSO 2010. We evaluated the bleaching of reefs at five localities both at three and five meter depth. The coral cover and densities of colonies were estimated. We recorded living coral cover, number and diameter of bleached and non-bleached colonies of each coral species. The colonies were classified according to the proportion of bleached area. Satellite images (Modis Scar) were analyzed for chlorophyll-a concentration and temperature in August, September, October and November from 2008-2010. Precipitation, wind speed and air temperature information was evaluated in meteorological data for 2009 and 2010. A total of 58.3 % of colonies, belonging to 11 hexacoral species, were affected and the greatest responses were observed in Colpophyllia natans, Montastraea annularis and Monta...
En Venezuela, los arrecifes coralinos del Parque Nacional Archipielago de Los Roques han sido rec... more En Venezuela, los arrecifes coralinos del Parque Nacional Archipielago de Los Roques han sido reconocidos como sistemas de gran diversidad biologica, en los que habitan numerosas especies de invertebrados, siendo el Phyllum Mollusca uno de los mas abundantes y diversos. El objetivo de este trabajo fue realizar un inventario de especies de moluscos asociados a estos arrecifes en 11 estaciones distribuidas a lo largo del Archipielago. Se determino la abundancia y riqueza especifica de los moluscos identificados hasta el renglon taxonomico superior, provenientes de la extraccion manual de entre 4 y 8 pilares de la especie Montastraea annularis en cada arrecife estudiado. Asociados a los corales se encontraron 390 ejemplares, contenidos en 3 clases: Bivalvia, Gasteropoda y Polyplacophora, representados en 29 familias y 49 especies, de los cuales, los bivalvos Atrina rigida, Isognomun bicolor, Ostrea froms Chama sarda, Lithophaga antillarum, L. aristata, L. nigra y L. bisulcata, Erycina ...
FIGURE 2. A, Migaya felis, 1 iving specimen and spawn. B, Navanax gemmatus. C, Chelidonura hirund... more FIGURE 2. A, Migaya felis, 1 iving specimen and spawn. B, Navanax gemmatus. C, Chelidonura hirundinina. D, Philine buchensis. E, Bulla occidentalis, ϳuveni 1 e. F, Bulla occidentalis. G, Haminoea cf. elegans. H, Lapinura divae. I, Aplysia dactylomela. J, Aplysia brasiliana. K, Aplysia juliana. L, Dolabrifera dolabrifera. M, Petalifera ramosa.
Ciencias Marinas, 2005
The objective of this study was to analyze the taxonomy of microgastropods associated with the bi... more The objective of this study was to analyze the taxonomy of microgastropods associated with the bivalve Arca zebra, an important fishing resource of the northern coast of Venezuela. The samples were obtained in the area of Chacopata, Sucre State, Venezuela. A total of 381 gasteropods were collected belonging to 25 species included in 12 families. The families with the highest number of species were Margellinidae (4), Collumbelidae (4) and Fisurellidae (3). Of the total of species collected, seven (Marginella haematita, Lucapina sowerby, Cantharus cancellarius, Crassispira tampanensis, Pyrgocytara coxi, Monilispira leusosyma and Terebra nasulla) represent new records for Venezuela, but can be catalogued as typical of the tropical western Atlantic.
The objective of this study was to analyze the taxonomy of microgastropods associated with the bi... more The objective of this study was to analyze the taxonomy of microgastropods associated with the bivalve Arca zebra, an important fishing resource of the northern coast of Venezuela. The samples were obtained in the area of Chacopata, Sucre State, Venezuela. A total of 381 gasteropods were collected belonging to 25 species included in 12 families. The families with the highest
![Research paper thumbnail of [Temporary abundance variation of Coralliophila abbreviata and Coralliophila caribaea (Mollusca, Coralliophilidae) in a coral reef at Morrocoy National Park]](https://attachments.academia-assets.com/86737959/thumbnails/1.jpg)
](Revista de biología tropical, 2008
The mollusks Coralliophila abbreviata and C. caribaea are coral predators in the Caribbean Sea . ... more The mollusks Coralliophila abbreviata and C. caribaea are coral predators in the Caribbean Sea . We evaluated the temporal variability of abundance and size structure of C. abbreviata and C. caribaea in Cayo Sombrero, Morrocoy National Park, Venezuelar (September 2004 - August 2005). The density of C. abbreviata and C. caribaea was evaluated monthly by means of two 50-meter long transects paralell to the coast line, at 3 m and 6 m deep; aditionally, 30 individuals of C. abbreviata were collected to measure size. The densities of C. abbreviata at the shallow transect fluctuated between 1.78 ind/m2 in September and 6.26 ind/m2 in May. The densities at the deep transect fluctuated between 4.23 ind/m2 in January and 7.66 ind/m2 in May. The densities of C. caribaea at the shallow transect fluctuated between 0 Ind/m2 (except in September) and 0.03 Ind/m2 (September) and the densities at the deep transect fluctuated between 0 Ind/m2 (October to March and July) and 0.1 Ind/m2 (April). Most ...
Revista de Biología Tropical, 2007
Predation rate of Coralliophila abbreviata (Neogastropoda: Coralliophilidae) on some coral specie... more Predation rate of Coralliophila abbreviata (Neogastropoda: Coralliophilidae) on some coral species at Parque Nacional Morrocoy, Venezuela. Coralliophila abbreviata is a tropical gastropod of the Caribbean Sea. This gastropod is an important corallivore. The objective of this work was to estimate the predation rate of C. abbreviata on some coral species in the coral reefs of Morrocoy National Park, Venezuela. The localities were Cayo Sombrero and Cayo Peraza. We evaluated the rate on five coral species: Montastraea annularis, Colpophyllia natans, Diploria strigosa, Diploria labyrinthiformis and Agaricia agaricites. We used three experimentals treatments. In treatment 1 we marked colonies with buoys that had been predated by C. abbreviata. In treatments II and III we used exclusion cages. Treatment II included the colony with its predators and treatment III was the control (only the colony). The injuries of the colonies were measured every 4 days for at least a month. The predation rate in treatment I varied depending on the coral species. The highest rate was on C. natans (3.70 cm 2 /Ind/day), while D. strigosa, D. labyrinthiformis and M. annularis did not register any predation rate (0 cm 2 /Ind/day). In treatment II we only detected predation activity in 1 colony of M. annularis with 0.15 cm 2 /Ind/day. The main effect generated by C. abbreviata on the Morrocoy National Park´s coral reefs is a decrease in the colonies´ reproduction and growth rate due to energetic use in tissue regeneration of injuries.
Revista de Biología Tropical, 2012
El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The aim of this... more El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The aim of this work was to evaluate the massive bleaching of coral reefs in Puerto Cabello, Venezuela derived from ENSO 2010. We evaluated the bleaching of reefs at five localities both at three and five meter depth. The coral cover and densities of colonies were estimated. We recorded living coral cover, number and diameter of bleached and nonbleached colonies of each coral species. The colonies were classified according to the proportion of bleached area. Satellite images (Modis Scar) were analyzed for chlorophyll-a concentration and temperature in August, September, October and November from 2008-2010. Precipitation, wind speed and air temperature information was evaluated in meteorological data for 2009 and 2010. A total of 58.3% of colonies, belonging to 11 hexacoral species, were affected and the greatest responses were observed in Colpophyllia natans, Montastraea annularis and Montastraea faveolata. The most affected localities were closer to the mainland and had a bleached proportion up to 62.73±36.55%, with the highest proportion of affected colonies, whereas the farthest locality showed 20.25±14.00% bleached and the smallest proportion. The salinity in situ varied between 30 and 33ppm and high levels of turbidity were observed. According to the satellite images, in 2010 the surface water temperature reached 31ºC in August, September and October, and resulted higher than those registered in 2008 and 2009. Regionally, chlorophyll values were higher in 2010 than in 2008 and 2009. The meteorological data indicated that precipitation in November 2010 was three times higher than in November 2009. Massive coral bleaching occurred due to a three month period of high temperatures followed by one month of intense ENSO-associated precipitation. However, this latter factor was likely the trigger because of the bleaching gradient observed. Rev.
Revista de Biología Tropical, 2006
C. abbreviata y C. caribaea son moluscos coralívoros del Mar Caribe. Evaluamos la variabilidad te... more C. abbreviata y C. caribaea son moluscos coralívoros del Mar Caribe. Evaluamos la variabilidad temporal de la abundancia y los cambios en la estructura de talla de C. abbreviata y C. caribaea en Cayo Sombrero, Venezuela (septiembre 2004-agosto 2005). Se colocaron transectas fijas de 50 metros de longitud a profundidades de tres y seis metros cada una, paralelas a la costa. Se evaluó mensualmente durante un año la densidad de ambos depredadores y se seleccionaron 30 individuos de C. abbreviata para medirlos cada mes. Las densidades de C. abbreviata en la transecta somera fluctuaron entre 1.78 ind/m2 en septiembre y 6.26 ind/m2 en mayo; las densidades de C. abbreviata en la transecta profunda estuvieron comprendidas entre 4.23 ind/m2 en enero y 7.66 ind/m2 en mayo. Las densidades de C. caribaea fluctuaron en la transecta somera entre 0 Ind/m 2 (todos los meses menos septiembre) y 0.03 Ind/m2 (septiembre) mientras que la transecta profunda fluctuó entre 0 Ind/m2 (octubre a marzo y juli...
Revista de biología marina y oceanografía, 2013
To date, 10 species of the genus Volvarina and one species of the genus Hyalina have been cited i... more To date, 10 species of the genus Volvarina and one species of the genus Hyalina have been cited in Venezuela, but only 2 of them are certain. In this paper 4 new species of mollusks of the family Marginellidae are described, based on specimens collected from 3 different locations: La Tortuga Island, Morrocoy National Park and Aves Island. Additionally, the records in Venezuela of all the species of both genus and the validity of Caribeginella flormarina, synonymized with Hyalina pallida, are discussed. Illustrations of the living animals for all the species are included, so as new photos of the shell of the Neotype of H. pallida, housed in the Natural History Museum in London. The new species are characterized by: Volvarina morrocoyensis Caballer, Espinosa & Ortea new species; 5 brownish bands in the shell, paired parallel plications, white body with red spots, mantle with black spots grouped in bands. Volvarina monchoi Caballer, Espinosa & Ortea new species; white shell with a brown band, uneven plications, white body without spots. Volvarina avesensis Caballer, Espinosa & Ortea new species; 3 orange bands in the shell, parallel plications, orange body, lacking spots, mantle with dull spots. Hyalina nelsyae new species; 3 dull bands in the shell, posterior plications divergent, anterior plications quasi-parallel, body with reddish spots forming a diamond in the tail, mantle with reddish spots forming 3 bands.
Biological Invasions
The movement of species is among the most serious environmental threats of the new millennium, as... more The movement of species is among the most serious environmental threats of the new millennium, as the transplantation of species beyond their native or historical range has intensified in the last five decades. Traditionally, studies on bioinvasions have focused on species that have been introduced, deliberately or accidentally, to biogeographic regions where they did not previously occur. However, less attention has been given to species movement to novel areas within the same biogeographic region. Our research group, the South America Introduced Molluscs Specialists, analyzed potential cases of native South American mollusc species introduced deliberately or accidentally beyond their natural range within South America. To achieve this, it is key to differentiate between anthropogenic processes and passive responses to environmental conditions. We considered the past and current spatial distribution of species, analyzed known or putative vectors, and discuss the impacts of taxonomic and nomenclatural knowledge. Based on the evidence currently available, we propose different scenarios to explain observed changes in mollusc distributions within South America. Seventeen transplanted mollusc species (TMS) were recognized, considering marine, freshwater, and terrestrial environments. Of the 189 South American ecoregions 31 were occupied by transplanted species, but this proportion varied by environment: 10 of 28 marine ecoregions, 12 of 52 freshwater ecoregions, and 9 of 109 terrestrial ecoregions. The ecoregions with TMS are generally located in the peripheral zones of the continent. Those with the highest number of TMS were the Southern Caribbean (three species) in the marine environment, the Central Andean Pacific Slopes (three species) in the freshwater environment, and the Alto Paraná Atlantic forests (two species) in the terrestrial environment. The number of unintentionally moved TMS is greater than those moved intentionally. The transplantation process is similar to the introduction and settlement process of non-native mollusc species, and so is their impact.
Fundación La Salle de Ciencias Naturales, May 20, 2019
Carmen Teresa Rodríguez y Samuel Elías Narciso-Fejure Resumen. Los ejemplares identificados en el... more Carmen Teresa Rodríguez y Samuel Elías Narciso-Fejure Resumen. Los ejemplares identificados en el presente trabajo fueron colectados manualmente en visitas ocasionales al arrecife coralino de Isla Larga, entre los años 2006, 2007 y 2009, y de forma sistemática sobre el gradiente de profundidad de 0 a 18 m durante los meses de mayo, junio y julio de 2010; a fin de tener un reporte taxonómico de las especies de bivalvos y gasterópodos de la zona. Se identificaron 23 familias dentro del Phylum Mollusca correspondientes a 38 especies de las Clases Bivalvia (21) y Gastropoda (17). Valores similares de riqueza de especies se han registrado en otros arrecifes del Caribe. El número de especies encontradas en un área de muestreo tan pequeña del Parque Nacional San Esteban, sugiere la necesidad de incrementar el esfuerzo de muestreo hacia otros arrecifes del mismo.
FIGURE 6. A, Aphelodoris antillensis. B, Platydoris angustipes. C, Sclerodoris prea. D, Felimare ... more FIGURE 6. A, Aphelodoris antillensis. B, Platydoris angustipes. C, Sclerodoris prea. D, Felimare acriba. E-F, Felimare fregona. G, Felimare kempfi. H, Coryphella dushia. I, Flabellina engeli. J, Flabellina verta. K, Austraeolis catina. L Nanuca sebastiani. M, Berghia creutzbergi. N, Cuthona iris. Ο, Tritoniopsis frydis. Sea s1ugs in their natura1 envirοnment (Gaby Carias).
FIGURE 5. A, Dondice occidentalis. B, Godiva rubrolineata. C, Favorinus auritulus. D, Phidiana ly... more FIGURE 5. A, Dondice occidentalis. B, Godiva rubrolineata. C, Favorinus auritulus. D, Phidiana lynceus. E, Spurilla sargassicola. F, Eubranchus conicla. G, Scyllaea pelagica. H, Doto casandra. I, Chelidonura cubana. J, Aplysia parvula. K, Syphonota geographica. L, Pleurobranchus areolatus. M, Elysia papillosa. N, Thuridilla malaquita. Ο-P, Placida cremoniana. Q, Okenia zoobotryon. I-Q, Sea s1ugs in their natura1 envirοnment (Gaby Carias).
FIGURE 4. A, Bursatella leachii. B, Cadlina rumia. C, Bermudella polycerelloides. D, Doris bovena... more FIGURE 4. A, Bursatella leachii. B, Cadlina rumia. C, Bermudella polycerelloides. D, Doris bovena. E, Polycera odhneri. F, Caribranchus morsomus, ventra1 view. G, Caribranchus morsomus, dοrsa1 view. H, Dendrodoris krebsii. I, Dendrodoris warta (fixed). J, Felimida binza. K, Felimida clenchi. L, Tyrinna evelinae. M, Felimare ruthae. N, Felimare samueli.
FIGURE 3. A, Phyllaplysia engeli. B, Stylocheilus striatus. C, Berthella agassizii. D, Lobiger so... more FIGURE 3. A, Phyllaplysia engeli. B, Stylocheilus striatus. C, Berthella agassizii. D, Lobiger souverbii. E, Oxynoe antillarum. F, Elysia crispata. G, Elysia ornata. H, Elysia flava. I, Elysia tuca. J, Elysia cauze. K, Cyerce habanensis. L, Ercolania fuscata. M, Placida verticilata. N, Costasiella nonatoi. Ο, Cylindrobulla beauii.
Abstract: El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The a... more Abstract: El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The aim of this work was to evaluate the massive bleaching of coral reefs in Puerto Cabello, Venezuela derived from ENSO 2010. We evaluated the bleaching of reefs at five localities both at three and five meter depth. The coral cover and densities of colonies were estimated. We recorded living coral cover, number and diameter of bleached and non-bleached colonies of each coral species. The colonies were classified according to the proportion of bleached area. Satellite images (Modis Scar) were analyzed for chlorophyll-a concentration and temperature in August, September, October and November from 2008-2010. Precipitation, wind speed and air temperature information was evaluated in meteorological data for 2009 and 2010. A total of 58.3 % of colonies, belonging to 11 hexacoral species, were affected and the greatest responses were observed in Colpophyllia natans, Montastraea annularis and Monta...
En Venezuela, los arrecifes coralinos del Parque Nacional Archipielago de Los Roques han sido rec... more En Venezuela, los arrecifes coralinos del Parque Nacional Archipielago de Los Roques han sido reconocidos como sistemas de gran diversidad biologica, en los que habitan numerosas especies de invertebrados, siendo el Phyllum Mollusca uno de los mas abundantes y diversos. El objetivo de este trabajo fue realizar un inventario de especies de moluscos asociados a estos arrecifes en 11 estaciones distribuidas a lo largo del Archipielago. Se determino la abundancia y riqueza especifica de los moluscos identificados hasta el renglon taxonomico superior, provenientes de la extraccion manual de entre 4 y 8 pilares de la especie Montastraea annularis en cada arrecife estudiado. Asociados a los corales se encontraron 390 ejemplares, contenidos en 3 clases: Bivalvia, Gasteropoda y Polyplacophora, representados en 29 familias y 49 especies, de los cuales, los bivalvos Atrina rigida, Isognomun bicolor, Ostrea froms Chama sarda, Lithophaga antillarum, L. aristata, L. nigra y L. bisulcata, Erycina ...
FIGURE 2. A, Migaya felis, 1 iving specimen and spawn. B, Navanax gemmatus. C, Chelidonura hirund... more FIGURE 2. A, Migaya felis, 1 iving specimen and spawn. B, Navanax gemmatus. C, Chelidonura hirundinina. D, Philine buchensis. E, Bulla occidentalis, ϳuveni 1 e. F, Bulla occidentalis. G, Haminoea cf. elegans. H, Lapinura divae. I, Aplysia dactylomela. J, Aplysia brasiliana. K, Aplysia juliana. L, Dolabrifera dolabrifera. M, Petalifera ramosa.
Ciencias Marinas, 2005
The objective of this study was to analyze the taxonomy of microgastropods associated with the bi... more The objective of this study was to analyze the taxonomy of microgastropods associated with the bivalve Arca zebra, an important fishing resource of the northern coast of Venezuela. The samples were obtained in the area of Chacopata, Sucre State, Venezuela. A total of 381 gasteropods were collected belonging to 25 species included in 12 families. The families with the highest number of species were Margellinidae (4), Collumbelidae (4) and Fisurellidae (3). Of the total of species collected, seven (Marginella haematita, Lucapina sowerby, Cantharus cancellarius, Crassispira tampanensis, Pyrgocytara coxi, Monilispira leusosyma and Terebra nasulla) represent new records for Venezuela, but can be catalogued as typical of the tropical western Atlantic.
The objective of this study was to analyze the taxonomy of microgastropods associated with the bi... more The objective of this study was to analyze the taxonomy of microgastropods associated with the bivalve Arca zebra, an important fishing resource of the northern coast of Venezuela. The samples were obtained in the area of Chacopata, Sucre State, Venezuela. A total of 381 gasteropods were collected belonging to 25 species included in 12 families. The families with the highest
Revista de biología tropical, 2008
The mollusks Coralliophila abbreviata and C. caribaea are coral predators in the Caribbean Sea . ... more The mollusks Coralliophila abbreviata and C. caribaea are coral predators in the Caribbean Sea . We evaluated the temporal variability of abundance and size structure of C. abbreviata and C. caribaea in Cayo Sombrero, Morrocoy National Park, Venezuelar (September 2004 - August 2005). The density of C. abbreviata and C. caribaea was evaluated monthly by means of two 50-meter long transects paralell to the coast line, at 3 m and 6 m deep; aditionally, 30 individuals of C. abbreviata were collected to measure size. The densities of C. abbreviata at the shallow transect fluctuated between 1.78 ind/m2 in September and 6.26 ind/m2 in May. The densities at the deep transect fluctuated between 4.23 ind/m2 in January and 7.66 ind/m2 in May. The densities of C. caribaea at the shallow transect fluctuated between 0 Ind/m2 (except in September) and 0.03 Ind/m2 (September) and the densities at the deep transect fluctuated between 0 Ind/m2 (October to March and July) and 0.1 Ind/m2 (April). Most ...
Revista de Biología Tropical, 2007
Predation rate of Coralliophila abbreviata (Neogastropoda: Coralliophilidae) on some coral specie... more Predation rate of Coralliophila abbreviata (Neogastropoda: Coralliophilidae) on some coral species at Parque Nacional Morrocoy, Venezuela. Coralliophila abbreviata is a tropical gastropod of the Caribbean Sea. This gastropod is an important corallivore. The objective of this work was to estimate the predation rate of C. abbreviata on some coral species in the coral reefs of Morrocoy National Park, Venezuela. The localities were Cayo Sombrero and Cayo Peraza. We evaluated the rate on five coral species: Montastraea annularis, Colpophyllia natans, Diploria strigosa, Diploria labyrinthiformis and Agaricia agaricites. We used three experimentals treatments. In treatment 1 we marked colonies with buoys that had been predated by C. abbreviata. In treatments II and III we used exclusion cages. Treatment II included the colony with its predators and treatment III was the control (only the colony). The injuries of the colonies were measured every 4 days for at least a month. The predation rate in treatment I varied depending on the coral species. The highest rate was on C. natans (3.70 cm 2 /Ind/day), while D. strigosa, D. labyrinthiformis and M. annularis did not register any predation rate (0 cm 2 /Ind/day). In treatment II we only detected predation activity in 1 colony of M. annularis with 0.15 cm 2 /Ind/day. The main effect generated by C. abbreviata on the Morrocoy National Park´s coral reefs is a decrease in the colonies´ reproduction and growth rate due to energetic use in tissue regeneration of injuries.
Revista de Biología Tropical, 2012
El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The aim of this... more El Niño Southern Oscillation (ENSO) has generated global coral massive bleaching. The aim of this work was to evaluate the massive bleaching of coral reefs in Puerto Cabello, Venezuela derived from ENSO 2010. We evaluated the bleaching of reefs at five localities both at three and five meter depth. The coral cover and densities of colonies were estimated. We recorded living coral cover, number and diameter of bleached and nonbleached colonies of each coral species. The colonies were classified according to the proportion of bleached area. Satellite images (Modis Scar) were analyzed for chlorophyll-a concentration and temperature in August, September, October and November from 2008-2010. Precipitation, wind speed and air temperature information was evaluated in meteorological data for 2009 and 2010. A total of 58.3% of colonies, belonging to 11 hexacoral species, were affected and the greatest responses were observed in Colpophyllia natans, Montastraea annularis and Montastraea faveolata. The most affected localities were closer to the mainland and had a bleached proportion up to 62.73±36.55%, with the highest proportion of affected colonies, whereas the farthest locality showed 20.25±14.00% bleached and the smallest proportion. The salinity in situ varied between 30 and 33ppm and high levels of turbidity were observed. According to the satellite images, in 2010 the surface water temperature reached 31ºC in August, September and October, and resulted higher than those registered in 2008 and 2009. Regionally, chlorophyll values were higher in 2010 than in 2008 and 2009. The meteorological data indicated that precipitation in November 2010 was three times higher than in November 2009. Massive coral bleaching occurred due to a three month period of high temperatures followed by one month of intense ENSO-associated precipitation. However, this latter factor was likely the trigger because of the bleaching gradient observed. Rev.
Revista de Biología Tropical, 2006
C. abbreviata y C. caribaea son moluscos coralívoros del Mar Caribe. Evaluamos la variabilidad te... more C. abbreviata y C. caribaea son moluscos coralívoros del Mar Caribe. Evaluamos la variabilidad temporal de la abundancia y los cambios en la estructura de talla de C. abbreviata y C. caribaea en Cayo Sombrero, Venezuela (septiembre 2004-agosto 2005). Se colocaron transectas fijas de 50 metros de longitud a profundidades de tres y seis metros cada una, paralelas a la costa. Se evaluó mensualmente durante un año la densidad de ambos depredadores y se seleccionaron 30 individuos de C. abbreviata para medirlos cada mes. Las densidades de C. abbreviata en la transecta somera fluctuaron entre 1.78 ind/m2 en septiembre y 6.26 ind/m2 en mayo; las densidades de C. abbreviata en la transecta profunda estuvieron comprendidas entre 4.23 ind/m2 en enero y 7.66 ind/m2 en mayo. Las densidades de C. caribaea fluctuaron en la transecta somera entre 0 Ind/m 2 (todos los meses menos septiembre) y 0.03 Ind/m2 (septiembre) mientras que la transecta profunda fluctuó entre 0 Ind/m2 (octubre a marzo y juli...
Revista de biología marina y oceanografía, 2013
To date, 10 species of the genus Volvarina and one species of the genus Hyalina have been cited i... more To date, 10 species of the genus Volvarina and one species of the genus Hyalina have been cited in Venezuela, but only 2 of them are certain. In this paper 4 new species of mollusks of the family Marginellidae are described, based on specimens collected from 3 different locations: La Tortuga Island, Morrocoy National Park and Aves Island. Additionally, the records in Venezuela of all the species of both genus and the validity of Caribeginella flormarina, synonymized with Hyalina pallida, are discussed. Illustrations of the living animals for all the species are included, so as new photos of the shell of the Neotype of H. pallida, housed in the Natural History Museum in London. The new species are characterized by: Volvarina morrocoyensis Caballer, Espinosa & Ortea new species; 5 brownish bands in the shell, paired parallel plications, white body with red spots, mantle with black spots grouped in bands. Volvarina monchoi Caballer, Espinosa & Ortea new species; white shell with a brown band, uneven plications, white body without spots. Volvarina avesensis Caballer, Espinosa & Ortea new species; 3 orange bands in the shell, parallel plications, orange body, lacking spots, mantle with dull spots. Hyalina nelsyae new species; 3 dull bands in the shell, posterior plications divergent, anterior plications quasi-parallel, body with reddish spots forming a diamond in the tail, mantle with reddish spots forming 3 bands.