Morphometric study of Acipenser nuccurii (Bonaparte, 1836) in fish farm individuals

The main objective of this study was to analyse differences and similarities in morphometric characteristics among specimens of the same year class of Acipenser naccarii (Bonaparte, 1836), comparing fish raised either in Italy or Spain. All specimens were F1 of captive broodstock in Italy. Fifteen biometric variables were measured, and three derived indices were calculated, on 30 individuals of 3+ year class from Lombardy (Italy) and 90 individuals of I+, 2+ and 3+ year class from Riofrio (Granada, Spain). A stepwise discriminate analysis (SDA) was carried out, and the results were contrasted using a non-hierarchical cluster analysis. The two groups proved to be similar, so a principal component analysis and a simple regression analysis were performed on all individuals, taking total length (TI) as the independent variable and all the biometric variables as dependent. The study revealed that although the Soljan index (i.e. ratio of mouth width to snout length) is related to TI, and is a valid taxonomic characteristic, the CA index (i.e. relative position of the barbels) and FB index (i.e. ratio of snout length to width) are also valid characteristics for individuals longer than 57 cm, being independent of TI

Temperature and photoperiod: what affects the nymphal development of Cornops aquaticum (Orthoptera: Acrididae)?

Development of the semi-aquatic acridid Cornops aquaticum on Eichhornia crassipes (Pontederiaceae) was investigated in the laboratory. Influence of constant (12 and 27 °C) and variable (36/3 °C and 36/4.5 °C) temperatures as well as constant (24 h day) and variable (14 h day/ 10 h night) photoperiods were analysed. The highest survival of nymphs (69 %) was obtained under an extreme photoperiod (24 h day) and constant temperature (27 °C). Both temperature and photoperiod were important for the development and number of nymphal stages, indicating a synergic effect

Un ejercicio de agrupación territorial: Ensayo académico con vistas a salvar problemas

The globalization process has changed the microeconomic advantages of firms’ location, andthe main characteristics of regional growth; as a result, the economic space of a great numberof countries has been altered. These international phenomena have revivified regional economicissues, which had been put aside by the mainstream long time ago. As a consequence, the problems related to regionalization have become crucial in many strategies of political economy.This paper deals with an academic exercise of regionalization.La aceleración de los procesos de globalización y la multiplicación de acuerdos de integraciónmodifican las ventajas microeconómicas de localización, y con ello el mapa económico de lospaíses. Entonces, por la profundidad de los shocks espaciales diferenciados, los temas regionales han adquirido renovado protagonismo. Las circunstancias actuales exigen que el espacio sea explícitamente incorporado en el análisis. En ese marco espacial se generan reacciones que se manifiestan, entre otras, en la pretendida conformación de regiones como posibilidad estratégica de respuesta a los desafíos. Sobre estos aspectos se centra el trabajo, ensayando un ejercicio académico de regionalización