Distribución vertical de los Quetognatos y sus variaciones Nictemerales al oeste de las Islas Galápagos, Ecuador durante enero 2006.
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2010
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El presente trabajo se efectuó al oeste de la isla Isabela, Galápagos durante los días
14-15 de enero de 2006, a bordo del buque de investigación Thomas Thompson de la
Universidad de Washington, Estados Unidos.
Para el estudio se efectuaron colectas de muestras de zooplancton empleando una
red con sistema de cierre a los estratos de 40-0, 100-40, 140-100m en la estación (E-1) y
en los estratos 40-0, 100-40, 180-100m correspondiente a (E-2) localizadas al oeste de
isla Isabela. Adicionalmente se colectaron muestras de agua para determinar clorofila a
y se obtuvieron los parámetros de temperatura, salinidad, oxígeno disuelto y nutrientes.
La distribución vertical de Sagitta pacifica presentó una preferencia durante el día
por el estrato 100-40m y migra durante la noche hacia el estrato de 40-0m.
S. bedoti fue abundante en la capa de 40-0m, esta especie posiblemente esté
asociada a la termoclina, debido que su mayor abundancia se registró en el estrato
superficial.
Krohnitta subtilis se capturó preferentemente en el estrato 100-40m y su
abundancia aumenta con la profundidad, lo que hace presumir que esta especie está
asociada a bajas temperaturas, bajo oxigeno disuelto y altas concentraciones de
nutrientes. Cabe señalar que K. subtilis no se registró en el estrato de 40-0m.
En cambio, la especie S. hexaptera se distribuyó en el estrato 40-0m siendo
abundante en las horas del día y en menor abundancia en la noche.
S. enflata se distribuyó en la columna de agua, en los estratos de 40-0m y 100-40m,
la cual fue disminuyendo su abundancia con la profundidad.
x
Con una escasa abundancia se registraron las especies S. neglecta y S. regularis,
observadas en el estrato superficial.
Estadísticamente se determinó que la distribución de las especies de quetognatos
comparando entre los estratos y estaciones no presentaron diferencias significativas a
microescala, al oeste de la isla Isabela.
2006, aboard the research vessel Thomas Thompson of the University of Washington, USA. For the study sample collections were made from zooplankton using a network locking system to the layers of 0-40, 40-100, 100-140 m in station (E-1) and the layers 0-40 m, 40-100, 100-180 m in station (E-2) localizated west of island Isabela. Additionally water samples were collected to determine chlorophyll a was obtained parameters of temperature, salinity, dissolved oxygen and nutrients. Vertical distribution of Sagitta pacifica submitted a preference during the day for the 100-40m layer and migrates at night to the layer of 0-40m. S. bedoti was abundant in the layer of 0-40m, this species may be associated with the thermocline, and due to its higher abundance was recorded in the surface layer. Krohnitta subtilis were captured mainly in the stratum 40-100 m and its abundance increases with depth, which seems to suggest that this species is associated with low temperatures, low dissolved oxygen and high nutrient concentrations. It should be noted that K. subtilis was not recorded in the stratum of 0-40 m. In contrast, the species S. hexaptera was distributed in the stratum 40-0m still abundant in the daytime and at lower abundance at night. S. enflata was distributed in the water column, in the strata of 40-0 m and 100- 40m, which was decreasing its abundance with depth. With a low abundance species were S. neglecta and S. regularis, observed in the surface layer. Statistically it is determined that the distribution of species of xii Chaetognatha comparing across strata and stations showed no significant differences at the microscale, west of Isabela Island.
2006, aboard the research vessel Thomas Thompson of the University of Washington, USA. For the study sample collections were made from zooplankton using a network locking system to the layers of 0-40, 40-100, 100-140 m in station (E-1) and the layers 0-40 m, 40-100, 100-180 m in station (E-2) localizated west of island Isabela. Additionally water samples were collected to determine chlorophyll a was obtained parameters of temperature, salinity, dissolved oxygen and nutrients. Vertical distribution of Sagitta pacifica submitted a preference during the day for the 100-40m layer and migrates at night to the layer of 0-40m. S. bedoti was abundant in the layer of 0-40m, this species may be associated with the thermocline, and due to its higher abundance was recorded in the surface layer. Krohnitta subtilis were captured mainly in the stratum 40-100 m and its abundance increases with depth, which seems to suggest that this species is associated with low temperatures, low dissolved oxygen and high nutrient concentrations. It should be noted that K. subtilis was not recorded in the stratum of 0-40 m. In contrast, the species S. hexaptera was distributed in the stratum 40-0m still abundant in the daytime and at lower abundance at night. S. enflata was distributed in the water column, in the strata of 40-0 m and 100- 40m, which was decreasing its abundance with depth. With a low abundance species were S. neglecta and S. regularis, observed in the surface layer. Statistically it is determined that the distribution of species of xii Chaetognatha comparing across strata and stations showed no significant differences at the microscale, west of Isabela Island.
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DISTRIBUCIÓN VERTICAL, ZOOPLANCTON, ESPECIES MIGRATORIAS, FACTORES AMBIENTALES