No abstract

In this paper is presented the percentage of fatty acids composition of three Artemia franciscana Mexican populations of epicontinentals waters; two are from natural environments (Coahuila and San Luis Potosí) and one (Texcoco) is a culture fed with Spirulina. Determination of fatty acids composition in each population, was performed by extraction of total lipid by the soxhlet method and the fatty acids methyl esters were determined by gas chromatography. The results show that Artemia of Texcoco contains the six fatty acids recommended for the culture of fish and crustaceans (16:0; 16:1; 18:1; 18:2w6; 18:3w3 and 20:5w3); Artemia from San Luis Potosí showed the poorest content in these acids and Artemia from Coahuila, although it showed a wide profile, it lacks the linolenic acid. When comparing results among the three populations with ecological data that have been published, it can be pointed out that the environment is decisive for this crustacean; Artemia from Texcoco fed with Spirulina showed the largest variety of fatty acids; the other two populations are wild, and lives in different habitats, Artemia of Coahuila is found in waters that are rich in sulfates and Artemia of San Luis Potosí lives in evaporation saltern ponds, built with stone blocks and therefore with scarce phytoplankton growth. Both Artemia populations showed deficiencies in essential fatty acids, mainly the last one.

Stylaster roseus en el Caribe colombiano es un común habitante de sus arrecifes coralinos, exceptuando la región de Santa Marta y la Guajira. S. roseus es una especie críptica que tiende a ubicarse en sitios sombreados, generalmente bajo o entre ramas de coral muerto o vivo. Se le observó entre esqueletos de Acropora palmata (2-6 m), sobre las partes laterales e internas de pináculos de Millepora (0.5-3 m), bajo tejados de Montastraea annularis y Agaricia spp. (15-30 m), y sobre embarcaciones hundidas (5-20 m). Adicionalmente se encontró creciendo sobre tejido vivo de Millepora, No se encontraron diferencias en las medidas promedio de colonias de hábitats similares. La coloración más común fue tronco blanco y ramas púrpura, seguida por la púrpura uniforme. Las formas dominantes en su orden fueron: las flabeladas o uniplanares, las ramificadas en dos planos y las arborescentes.

The evolution of 40 wintering areas of Grus grus in the south-west of the Iberian Peninsula has been studied, including the traditional wintering places of this species on its western route. Eight of these areas harboured 50% of the whole population using this route, and none of the 40 areas showed a decline in the number of birds during the study period. At present the number of cranes in each area is much greater than in the 1979-1980 winter. No geographical trends have been observed regarding the magnitude of the increase, which is closely related to that observed for the whole Spanish and Palearctic populations. Despite the emergence of some new wintering areas, the magnitude of the increase is greater in more southerly parts of the range. This may be a consequence of greater diversity and availability of food in these latitudes. The influence of enhanced international protection and agricultural food sources on the appearance of new wintering areas is discussed.