The preferred temperature (PT) of Poecilia sphenops (Pisces, Poeciliidae) (n = 240, 1.13 +/- 0.06 g wet weight, 3.26 +/- 0.88 cm standard length) from Presa Piedra Azul, Oaxaca, Mexico, was measured at acclimation temperature of 20 degreesC, 23 degreesC,…

Diabetes mellitus is a syndrome which affects more and more people in all countries over the world. In Mexico, it is commonly treated with herbal extracts. Such treatment may be of considerable benefit especially during the early stages of the…

Early in the twentieth century it was shown that Mendel's laws apply to plants and animals and that genes reside on chromosomes. In the 1950s the double-helix model of DNA inaugurated the molecular biology era, which culminated at the end…

A new terrestrial species of Pseudoeurycea is described from the mountains of the Mixteca region of Oaxaca. Compared with other members of the genus, the new species is relatively slender and short-legged. The background color of the dorsum of this…

While biologists have been aware of the existence of native Mexican trouts for over a century, they have received little study. The few early studies that did muchmore than mention their existence began in the 1930s and continued into the…

Knowledge about fresh water bodies biology in the State of Tlaxcala, Mexico, has become of relevant importance in order to diagnosticate possibilities about natural aquatic renewable resources management for an optimum exploitation. For first ocassion, Apizaquito Reservoir in the State,…

Protein assemblies with a high degree of repetitiveness and organization are known to induce strong immune responses. For that reason they have been postulated for the design of subunit vaccines by means of protein engineering. The enzyme lumazine synthase from…

In Mexico, the Knowledge of theprotozoa related lo mollusks, begin with the report of trhee forms associated to the oyster Crassotera corteziensis Hertlein, collected in the pacific coast in San BIas, Nayarit. From the Gulf the México, was protozoologically analysed…

The purpose of this research is to contribute to knowledge of taxonomy, ecological and local importance of freshwater mollusks inhabiting the Atlangatepec Reservoir, Tlaxcala. Four gastropoda pulmonata families were registered end represented by Physella sp [Physidae]; Planorbella trivolvis Say and…

One of the habitats occupied by Mammillaria magnimamma is a 2000-year old lava-field, in Mexico City. The great ecological interest on this lava-field and the little knowledge there is regarding cacti population ecology have compelled us to analyse the demography…