Papers by Esperanza Buitrago
Conditions jor obtaining adventitious buds jrom shoot tips oj Podocarpus guatemalensis (Standley)... more Conditions jor obtaining adventitious buds jrom shoot tips oj Podocarpus guatemalensis (Standley) cultured in Vitro were stablished. The explants were sur:face sterilized by inmersion in 2.5 per 100 sodium hypochlorite jor jour minutes. The jormation of adventitious buds was stimulated _soaking the shoot tips in 100 mg!L EDTA solution jor 20 minutes befare transjering them on aANA (0.0-0.02rng!L) andBA (2.5 -5.0rng!L) supplemented Gressho.ff and Doy (G.D.) liquid medium The buds were cultured under red light and a photoperiod oj 16 h at 24°C. Ajter 30 days oj culture, the buds were tranjerred to G.D. medium diluted 1:1, without hormones and supplemented with 5 per 100 glicine, 3 per 1 00 sucrose and 1 per 100 actived charcoal to stimulate the development adventuious bud primordia. Each explant jormed 1 - 1 O adventitious buds.
Revista Cientifica Facultad De Ciencias Veterinarias Universidad Del Zulia, 2004
It was evaluated the growth and survival of Crassostrea rhizophorae juveniles (30 mm) in suspende... more It was evaluated the growth and survival of Crassostrea rhizophorae juveniles (30 mm) in suspended culture in relation with environmental factors in Golfo de Cariaco, Venezuela, during six months (june-november 2002), in the period of discontinued upwelling and water stratification. Juveniles were maintained in enclosures with 100 individuals suspended to long line at 2-3 m from the surface. The oysters were analyzed monthly determining shell dimensions and dry mass of shell, and soft body, and fouling organisms on shells. Temperature was continually recorded with electronic thermographs and food availability (total and organic seston and phytoplanktonic biomass), oxygen concentration and salinity were determinated weekly. The 15-mm increase in shell height and the 70% of survival suggest a low culture feasibility of C. rhizophorae in Golfo de Cariaco (Turpialito locality). Slow growth rates were related to low food availability, mainly phytoplanktonic biomass. Fouling in enclosures and on shells, in addition to predation, principally by Cymatium spp. gastropods, were negative factors for culture. Reproduction could be an endogenous factor that affects somatic growth. Studies of growth and survival in continuing upwelling period (january-june), where food availability is high, as well as studies of fouling and predation influences are necessary to establish strategies for the C. rhizophorae culture in the Golfo de Cariaco.
hasta los de índole biológicas, como las mareas rojas y la depredación. En este último aspecto, l... more hasta los de índole biológicas, como las mareas rojas y la depredación. En este último aspecto, la mortalidad causada por la acción de algunos depredadores es la que más afecta la producción en la industria de la acuicultura marina y por lo tanto su rentabilidad económica (HICKMAN 2001).
Conditions jor obtaining adventitious buds jrom shoot tips oj Podocarpus guatemalensis (Standley)... more Conditions jor obtaining adventitious buds jrom shoot tips oj Podocarpus guatemalensis (Standley) cultured in Vitro were stablished. The explants were sur:face sterilized by inmersion in 2.5 per 100 sodium hypochlorite jor jour minutes. The jormation of adventitious buds was stimulated _soaking the shoot tips in 100 mg!L EDTA solution jor 20 minutes befare transjering them on aANA (0.0-0.02rng!L) andBA (2.5 -5.0rng!L) supplemented Gressho.ff and Doy (G.D.) liquid medium The buds were cultured under red light and a photoperiod oj 16 h at 24°C. Ajter 30 days oj culture, the buds were tranjerred to G.D. medium diluted 1:1, without hormones and supplemented with 5 per 100 glicine, 3 per 1 00 sucrose and 1 per 100 actived charcoal to stimulate the development adventuious bud primordia. Each explant jormed 1 - 1 O adventitious buds.
![Research paper thumbnail of [Larvae and postlarvae production of the green-white sea urchin Lytechinus variegatus (Echinodermata: Echinoidea) in culture conditions]](https://a.academia-assets.com/images/blank-paper.jpg)
Revista de biología tropical, 2005
We evaluated the biological feasibility of massive larvae and postlarvae production of the Caribb... more We evaluated the biological feasibility of massive larvae and postlarvae production of the Caribbean green-white urchin Lytechinus variegatus. Experiments were designed to choose the initial larval density and microalgae diets under culture, to study metamorphosis, postlarval and juvenile growth. Massive production of competent larvae 650 microm long at 12-13 days is possible using larval densities of 0.25 to 1 larva/ml. The microalgae Rhodomonas sp. was suitable for the optimization of larval growth and survival. Metamorphosis of 100% of the larvae can be induced with films of bentic diatoms (Navicula sp. and Amphora sp.), after 96 h; however, diatoms are not adequate for postlarval development and a food supply of Ulva lactuta is necessary for proper growth. For juveniles, a diet of macroalgae (U. lactuta) and/or commercial marine shrimp culture pellet food is enough for growth, but the best results were obtained with shrimp or U. lactuta used alone (85-86%, against 46% with the m...
Mem. Fund. La Salle de Cienc. Nat, 2000
Aquaculture International, 2007
An organic culture media based on a composted liquid seaweed extract was developed and tested for... more An organic culture media based on a composted liquid seaweed extract was developed and tested for growth of Chaetoceros muelleri. The extract was evaluated at two concentrations and then compared with two commercial media: Walne and agricultural fertilizer (AF). The concentrations of nitrogen and phosphorous differed between the two commercial media and the seaweed extract; however, growth of Chaetoceros muelleri was similar. The successful culture of Chaetoceros muelleri in composted liquid seaweed extract suggests the feasibility of and potential use for this natural, organic fertilizer in aquaculture. The seaweed extract is simple to obtain and inexpensive.
Aquaculture International, 2005
We evaluated the mass production of competent larvae of the sea urchin Lytechinus variegatus cult... more We evaluated the mass production of competent larvae of the sea urchin Lytechinus variegatus cultured at three initial densities (0.25, 0.5, and 1 larvae per ml) and fed Chaetoceros muelleri. Survival, length, dry weight of larvae, and larval stage index (LSI) were estimated in each treatment as a function of the density. Density decreased during the experiment due to mortality, but the percentage was similar in all three treatments (68.5, 66.7, and 76.0%). The experiment was stopped at 13 days after fertilization, when most of the larvae were competent and had settled. There were no significant differences in survival (exceeded 65% in all treatments), length and larval stage index among treatments. However, larvae weight in the two low density treatments (1.1 ± 0.11 mg and 1.2 ± 0.05 mg, respectively) was greater than the high density treatment (0.59 ± 0.376 mg). This study demonstrates that competent larvae of Lytechinus variegatus can be produced with less than 25% mortality in 13 days when cultures are started at densities of 0.25-1 larvae/ml. Culturing at higher densities (0.5-1 larvae/ml) had no apparent disadvantages and would reduce the cost of production.
Aquaculture, 2007
We ran an experiment on mangrove oysters Crassostrea rhizophorae to evaluate the effects of addin... more We ran an experiment on mangrove oysters Crassostrea rhizophorae to evaluate the effects of adding different masses of artificial fouling to the upper valve, either to the umbo region or the ventral edge of the shell. Growth and survival were quantified after a 30 d period in suspended culture in the La Restinga Lagoon, Venezuela. The artificial fouling was cement weighing 0.5, 1, 2 or 3 fold the mass of the upper valve. No fouling was added to a control group. Fouling mass, but not the position of the artificial fouling, affected growth in shell length. However, only the heaviest fouling (3 times the mass of the upper valve) had a significant effect. In contrast, there was no affect of either fouling mass or position on tissue growth. Finally, our data indicated that mortality could be affected by the position where we added artificial fouling (greater mortality when fouling was added to the ventral edge of the shell), but not by fouling mass. Our study indicates it is unlikely that the levels of natural fouling that develop on oysters in suspended culture would be sufficient to affect either growth or survival.
Aquacultural Engineering, 2005
This study presents data from over 7 years on the numbers of spat settling onto plastic bottles (... more This study presents data from over 7 years on the numbers of spat settling onto plastic bottles (2 l soda bottles). The bottles were cut longitudinally into two halves and suspended in a series from 0.10 to 2.00 m in depth in the ''Laguna de la Restinga'' on Margarita Island, Venezuela. The surface area of one entire collector was 1.8 m 2 (formed by 20 bottles halves) and the average number of oysters attaching after a deployment period of 1 month was 326 spat/m 2 (and the monthly average ranged from 42 to 1496 over 7 years). Plastic bottles used in this way provided an efficient and cost-effective means of collecting oyster spat, and the spats were easily detached because of the flexibility of the plastic surfaces.
Environmental Management, 2005
/ Oyster culture has a potential to generate income for coastal communities and to lessen pressur... more / Oyster culture has a potential to generate income for coastal communities and to lessen pressure on natural overexploited populations. A project to transfer mangrove oyster Crassostrea rhizophorae raft culture technology to selected coastal communities in Margarita Island, Venezuela is being developed, and an optimum location selection technique was devised. To pick the variables or factors that determine site suitability, a bibliographic database was made, aspects of interest chosen, and the most comprehensive ones singled out, eliminating redundant ones. Twenty variables were grouped in criteria
It was evaluated the growth and survival of Crassostrea rhizophorae juveniles (30 mm) in suspende... more It was evaluated the growth and survival of Crassostrea rhizophorae juveniles (30 mm) in suspended culture in relation with environmental factors in Golfo de Cariaco, Venezuela, during six months (june-november 2002), in the period of discontinued upwelling and water stratification. Juveniles were maintained in enclosures with 100 individuals suspended to long line at 2-3 m from the surface. The oysters were analyzed monthly determining shell dimensions and dry mass of shell, and soft body, and fouling organisms on shells. Temperature was continually recorded with electronic thermographs and food availability (total and organic seston and phytoplanktonic biomass), oxygen concentration and salinity were determinated weekly. The 15-mm increase in shell height and the 70% of survival suggest a low culture feasibility of C. rhizophorae in Golfo de Cariaco (Turpialito locality). Slow growth rates were related to low food availability, mainly phytoplanktonic biomass. Fouling in enclosures...
It was evaluated the growth and survival of Crassostrea rhizophorae juveniles (30 mm) in suspende... more It was evaluated the growth and survival of Crassostrea rhizophorae juveniles (30 mm) in suspended culture in relation with environmental factors in Golfo de Cariaco, Venezuela, during six months (june-november 2002), in the period of discontinued upwelling and water stratification. Juveniles were maintained in enclosures with 100 individuals suspended to long line at 2-3 m from the surface. The oysters were analyzed monthly determining shell dimensions and dry mass of shell, and soft body, and fouling organisms
Mangrove oyster, Crassostrea rhizophorae , is one of the mollusks with greatest perspectives for ... more Mangrove oyster, Crassostrea rhizophorae , is one of the mollusks with greatest perspectives for aquaculture development in the Caribbean and the tropical Atlantic coast. Even though, many studies have been carried out to establish its culture, there has not been established which and how environmental factors influence its growth under culture condition. Spats with a mean size of 30 mm were suspended in “Spanish baskets” at a depth of 4 m during 6 months. The experiment was carried on at La Restinga lagoon, Margarita Island, Venezuela. Each month oysters were measured (ventral-dorsal and antero-posterior), and weighted (dry weight from conch, tissue and fouling). Survivorship was also evaluated. Water temperature was recorded continuously and weekly measurements of Secchi depth, salinity, oxygen, total, organic and inorganic seston, and chlorophyll a were determined. Results show 89% increase in ventral-dorsal size reaching sizes of 54.5 mm. Dry weight of tissue at the end of the s...
Page 1. 67 MEMORIA Fundación La Salle de Ciencias Naturales Tomo LIX, número 151, enero/junio 199... more Page 1. 67 MEMORIA Fundación La Salle de Ciencias Naturales Tomo LIX, número 151, enero/junio 1999 EL BANCO DE CEPAS DE MICROALGAS DE LA ESTACIÓN DE INVESTIGACIONES MARINAS DE MARGARITA, FUNDACIÓN LA SALLE DE CIENCIAS ...
The growth of the microalgae Isochrysis aff. galbana variety tahitiana, Chaetoceros gracilis and ... more The growth of the microalgae Isochrysis aff. galbana variety tahitiana, Chaetoceros gracilis and Chaetoceros sp was studied using four culture media: algal, F/2, agricultural fertilizer (FA) and Walne. The cultures were performed in 800 ml bottles in water with 30 units of salinity. The light cycle was 12 hours light:12 hours dark with a light intensity of 45 mmol quanta m-2 s-1. Cultures were aerated with CO2 rich air. The maximum cell concentration of phytoflagellates was obtained in FA cultures. The cell density obtained in these cultures was 45.4% higher than that obtained in F/2, 41.6% higher than in Walne, and 7.9% than in algal media. The maximum cell concentration of Chaetoceros gracilis was obtained with Walne media. The cells reached a cell density between 2.9 and 40.8%. The media with the highest cell density for Chaetoceros sp. was FA where the cell concentration was between 3.3 and 42.4%. There were significant statistical differences among the exponential phases obtain...
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Papers by Esperanza Buitrago