Browsing by Subject "Cyprinidae"

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    Edad y crecimiento de Gobio lozanoi Doadrio & Madeira, 2004 (Cypriniformes: Cyprinidae) en sectores fluviales de la cuenca del río Segura (SE península ibérica)
    (Murcia: Servicio de Publicaciones de la Universidad de Murcia, 2013) Amat Trigo, Fátima; Oliva Paterna, Francisco José; Verdiell Cubedo, David; Ruiz Navarro, Ana; Torralva Forero, María del Mar; Zoología y Antropología Física
    El trabajo estudia la estructura de edad, longitud retrocalculada y tasa de crecimiento en poblaciones de Gobio lozanoi a lo largo de los principales ejes fluviales de la cuenca del río Segura (ríos Segura y Mundo). Se analizaron estos parámetros con individuos capturados en otoño de 2009 y en 19 localidades, así como su relación con variables ambientales (altitud, estado ecológico y conductividad). Las poblaciones reflejaron seis clases de edad (0+ a 5+) con escasas diferencias entre sexos y dominancia de edades intermedias (2+ y 3+). La estructura de edades mostró variaciones significativas en el gradiente con tendencia a presentar menor número de clases en localidades a menor altitud. La tasa de crecimiento se relacionó negativamente con la longevidad y mostró diferencias entre sectores fluviales. La tasa de crecimiento en la fase de transición a la madurez mostró tendencia a disminuir con el gradiente, pero también conforme decrece el estado ecológico y aumenta la conductividad.
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    Predicting shifts in the climate space of freshwater fishes in Great Britain due to climate change
    (Elsevier, 2016) Ruiz Navarro, Ana; Didáctica de las Ciencias Experimentales
    The implications of climate change for terrestrial and aquatic taxa are for their dispersal pole-wards and/ or to higher altitudes as they track their climate niches. Here, bioclimatic models are developed to predict how projected climate change scenarios for a northern temperate region (Great Britain) shift the climate spaces (i.e. areas of suitable thermal habitat) for 12 freshwater fishes of the Salmonidae, Percidae, Esocidae and Cyprinidae families. Climate envelope models developed in Biomod2 used the current species' distributions and their relationships with current climatic variables, and projected these onto the BCC-CSM1-1 and HadGEM2-AO climate change scenarios (low and high emissions, 2050 and 2070) in full and no dispersal scenarios. Substantial contractions in climate spaces were predicted for native salmonid fishes, with decreases of up to 78% for Atlantic salmon Salmo salar, with these largely unchanged between the dispersal scenarios. Conversely, for the majority of cyprinid fishes, expansions were predicted, including into northern regions where they are current not present biogeographically. Only under the no dispersal scenarios did their predicted distributions remain the same as their current distributions. For all non-salmonid species, the most important climate variables in the model predictions related to temperature; for salmonids, they were a combination of temperature and shifts in annual mean precipitation. As these predictions suggest that there is potential for considerable alterations to the climate spaces of freshwater fishes in Great Britain during this century then regulatory and mitigation conservation actions should be undertaken to minimise these.