Eufáusidos (Euphasiacea) de Isla Malpelo, Pacífico Occidental colombiano.

• Published in: Revista de Biología Tropical
• Main Authors: Rivera Gómez, Marisol, Giraldo, Alan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidad de Costa Rica 2019
• Subjects: nictemeral variation; Euphausia diomedeae; Euphausia distinguenda; Colombia; vertical migration; variación nictemeral; migración vertical; Pacific; Polar Biology
• Online Access: https://revistas.ucr.ac.cr/index.php/rbt/article/view/31197; https://doi.org/10.15517/rbt.v67i1.31197

Euphausiids migrate vertically in the water column as part of their diel cycle. These migrations make them a key element in the biological pump of the pelagic environment. We took stratified zooplankton samples (0-50, 50-100, and 100-150 m) during the Pacífico-ERFEN campaign in September 2012 to evaluate the vertical distribution of euphausiids around Malpelo Island (3.8 - 4.2 N, 81.4 - 81.8 W). A total of 10 species belonging to four genera were identified. Euphausia diomedeae was the most abundant species in the 0-50 and 100-150 m layers, whereas E. distinguenda was the most abundant species in the 50-100 m layer. Based on quasi-Poisson generalized linear distribution models we found that abundance in the 50-100 m layer was significantly higher than in the 100-150 m layer (t = 3.05, p < 0.05). There were no significant differences associated with sampling hour (diurnal/nocturnal) (t = 0.07, p = 0.94). We calculated a vertical distribution index (VDI) based on abundance, which showed that euphausiid species were concentrated in the 50-100 m layer during day and night. Calyptopis larvae dominated in abundance at all depth layers, followed by furcilia larvae, juveniles and adults. The abundance of the latter increased gradually from the most superficial layer to the deepest layer, whereas juveniles showed the opposite pattern. This is the first study to describe the taxonomic composition, and vertical and spatial distribution of euphausiids associated with Malpelo Island, Colombian Pacific. Los eufáusidos realizan migraciones verticales en la columna de agua como parte de un ciclo nictemeral, estas migraciones los convierten en un elemento clave de la bomba biológica del ambiente pelágico. Con el propósito de evaluar la distribución vertical de los eufáusidos alrededor de la isla Malpelo (3.8 - 4.2 N y 81.4 - 81.8 W), se tomaron muestras estratificadas (0-50, 50-100 y 100-150 m) de zooplancton durante la campaña Pacífico-ERFEN de septiembre de 2012. Se identificaron un total de 10 especies pertenecientes a ...