The outcrop of the underlying substratum of the Maspalomas dune field (Gran Canaria, Canary Islands): a sing of a sedimentary deficit

The outcrop of the underlying substratum of the Maspalomas dune field (Gran Canaria, Canary Islands): a sing of a sedimentary deficit

Efecto del color del sustrato en el comportamiento de fijación del caballito de mar de hocico corto (Hippocampus hippocampus)

El caballito de mar (Hippocampus hippocampus) presenta una fase planctónica durante los primeros días de su vida. Cuando cambia a la fase bentónica ha de fijarse en un sustrato adecuado con su cola prensil. Este estudio, realizando recuentos diarios de la distribución de los caballitos en el acuario, ha obtenido como resultado que no existe una preferencia entre el color rojo y azul del sustrato a la hora de la fijación, no obstante, se observó una adaptación progresiva de los peces al sustrato artificial.The seahorse (Hippocampus hippocampus) presents a planktonic phase during the first days of life. During settlement, it fixes to a suitable substratum using its prehensile tail. This study, through a daily counts of the seahorse distribution in the aquarium, established that juveniles seahorse do not show a preference between the red or blue fixation substrates. However, it was observed a progressive adaptation of the fish to the artificial handmade substratum.

Morphogenesis of the Ourense plains:(NW of Spain)

[EN] We present a geomorphological analysis of Ourense Province (NW Spain) characterized by: a general narrowing of the fluvial network, highlands with smooth reliefs partially eroded and lowlands with residual reliefs, several extensive plains of erosion frequently limited by fractures -among which Tertiary grabens are inserted-, some ?Hollow Surface?-type morphology, absence of sedimentary deposits outside the grabens, and a generalized outcrop of the Hercynian Massif substratum. Traditionally, this ?piano?s keyboard morphology? has been interpreted as expression of block tectonics in tensile regimen; instead we suggest the existence of: an isostatic upheaval simultaneous to a sequence of tectonic pulses of compressive regimen with activity in favour of transcurrent faults, a General Surface (R600), several plains that present a ?Hollow Surface?-type morphology (R1600 R1400 R1000), a generalized alteration that correspond to a same process of decomposition associated to fluctuating conditions of redox equilibrium, a erosional terraces related principaly to the palaeo-fluvial nets; moreover, we propose the existence of two morphoestructural lineament: the first one represented by the Fault of Vila Real (NE-SW) -a ramification of the ?Basal Pyrenean Overthrust?-, that would have been active at an early moment of the tectonic sequence with a left transcurrent fault, secondly the lineament represented by the Fault of Maceda (NNW-SSE) that would be related to the ?Fault System NW-SE? and would have produced a right transcurrent fault during a late tectonic pulse.