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Results for “Limnetica”

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Influencia de factores ambientales y biométricos en la capacidad de nado del barbo ibérico (Luciobarbus bocagei Steindachner, 1864), un ciprínido potamódromo endémico de la Península Ibérica

El presente trabajo analiza la capacidad voluntaria de nado del barbo ibérico ( Luciobarbus bocagei Steindachner, 1864) en un canal abierto durante su época de migración, relacionándola con factores ambientales y biométricos. La temperatura del agua, la velocidad de flujo y la longitud del pez fueron los factores de mayor importancia que condicionaron la velocidad de nado de los barbos y su tiempo de fatiga. Dentro del rango de valores estudiado, el barbo ibérico pudo mantener velocidades de nado en sprint (> 15 BL/s) durante 3-10 s, y de 17-117 s en el modo de natación prolongada (7-15 BL/s). Los resultados aportados pueden ser empleados como una herramienta útil para la gestión de sus poblaciones, principalmente para el diseño de pasos para peces. This paper analyzes the volitional swimming capacity of the Iberian barbel ( Luciobarbus bocagei Steindachner, 1864) in an open flume during its migration period, in relation to environmental and biometric factors. Water temperature, flow velocity and fish length were the most important factors which affected the swimming speed of barbels and their fatigue time. Within the range of values studied, the Iberian barbel was able to maintain sprint swim speeds (> 15 BL/s) for 3-10 s, and 17-117 s in prolonged swim mode (7-15 BL/s). The results can be used as a tool for the management of barbel populations, mainly in the design of fishways.

Limnetica

Endozoochory of seeds and invertebrates by migratory waterbirds in Oklahoma, USA

Given their abundance and migratory behavior, waterbirds have major potential for dispersing plants and invertebrates within North America, yet their role as vectors remains poorly understood. We investigated the numbers and types of invertebrates and seeds within freshly collected faecal samples (n = 22) of migratory dabbling ducks and shorebirds in November 2008 in two parts of Lake Texoma in southern Oklahoma. Killdeer Charadrius vociferus were transporting a higher number and diversity of both plants and invertebrates than the green-winged teal Anas carolinensis. Ten plant taxa and six invertebrate taxa were identified to at least genus level, although viability was not confirmed for most of these taxa. Bryozoan statoblasts (from four species not previously recorded from Oklahoma) were especially abundant in killdeer faeces, while the ostracod Candona simpsoni was detected as a live adult in torpor in the teal faeces. Cyperaceae and Juncaceae were the most abundant plant families represented and Cyperus strigosus seeds germinated after extraction from killdeer faeces. This snapshot study underlines the importance of waterbirds as vectors of passive dispersal of many organisms and the need for more research in this discipline.

Oklahoma