Boletín del Centro de Investigaciones Biológicas

Tabla de Contenido

2024-12-30T11:29:03+00:00

Leaf dimensions and photosynthesis of Rhizophora mangle in estuarine areas under contrasting hydrological conditions

2024-12-30T14:03:22+00:00

In El Tablazo Bay and the mouth of the Maracaibo Strait (≈ 10.7º–11.1º N; 71.6º–71.8º W) R. mangle communities grow under a semi-arid climate with 500–600 mm annual precipitation. There, the mangrove grows on soils with no apparent nutritional limitations (N, P) and moderate salinity (7–9 ‰), reaching average heights of around 17 m. Leaf dimensions and light saturated photosynthesis were measured in two areas subjected to hydrological regimes causing differences in the sediment concentrations of K, Na y N. The leaf mass/area ratios (157–173 g m-2) were within the margins reported for R. mangle over a wide latitudinal and precipitation range, but without nutritional deficiencies. The average succulence (268–282 g water m-2) reached values similar to those of Caribbean mangroves, but lower than the average observed in higher salinity sites. Mean rates of photosynthesis (11.3–12.2 μmol m-2 s-1) and stomatal conductance (149–172 mmol m-2 s-1) coincided with those of non-nutrient-limited communities across the latitudinal range of the species. The edaphic differences in the studied sites are reflected in variations in leaf mass and the degree of succulence, but do not generate significant changes in the gas exchange. The averages of N concentration, conductance, photosynthesis and intrinsic water use efficiency can be used as reference to estimate ecological effects caused by water stress, nutrition, and salinity.

Unpublished species of aquatic beetles of the genus Anacaena in the Upper Apure, Venezuela (Hydrophilidae: Chaetarthriinae: Anacaenini)

2024-12-30T14:05:29+00:00

Seven new species of the genus Anacaena Thomson, 1859 are described from region of Alto Apure, Venezuela: A. crenituloides sp. n., A. hospesa sp. n., A. llanera sp. n., A. mantecala sp. n., A. pallida sp. n., A. paulincarmenae sp. n. and A. samana sp. n., closely related morphologically, representing a new group of species within the Neotropical genus Anacaena. All of them are associated with the same lentic environment, inhabiting the muddy sediments of shallow water bodies. Detailed illustrations of the type specimens are presented, including habitus and genitalia, as well as a satellite image that locates the collection points in the trunk 19 of the Barinas-Apure highway.

Phagocytosis rate in Acanthamoeba species from groundwater. Part 2.

2024-12-30T14:09:32+00:00

The phagocytosis is a mechanism of take of solid particles by eukaryotic cells, playing a role in the ecology. The objective of this work was analyzed the phagocytosis of Acanthamoeba species from groundwater of Mezquital Valley (Hidalgo State, Mexico), and their biology impact. For this, a mathematics model was elaborate for evaluated rates of phagocytosis, vacuole forming, clearing of bacteria, adherence and digestion for Acanthamoeba species. The phagocytosis rate was ≥ 50 a 250 bac ame-1 h-1 both species; at the same time that the vacuole forming rate were ≥ 20 an 80 vac. ame-1 h-1. The clearing rates were 100.000 bac-1 mm2 cells-1 h-1 for Acanthamoeba griffini, until 1.200.000 bac-1 mm2 cells-1 h-1for Acanthamoeba castellanii. The adherence rate was ≥ 500.000 bac-1ame-1 h-1 mm2 by membrane superface. The phagocytosis process was regulated by the bacteria adherence rate on the amoebic superface, in positive correlation with the digestion rates. In conclusion the phagocytosis depended of Acanthamoeba species´s and cellular factors as vacuole forming and bacterial adherence on the membrane superface of amoeba. The ecological impact of Acanthamoeba is determined by the clearing rate of bacteria by amoeba. In this work was demonstrated the importance of phagocytosis and the role of free living amoebae in the regulation of bacteria in the environmental.

Contribution to the knowledge of the artisan fishing activity of the Blue crab Callinectes sapidus (Brachyura: Portunidae) in two geographical areas of the Cabimas Municipality, Venezuela

2024-12-30T14:09:37+00:00

This research aimed to evaluate the artisanal fishing activity of the blue crab Callinectes sapidus (Brachyura: Portunidae) in two geographical areas of the Cabimas municipality, Venezuela. In the study in the "Parque la Laguna Azul" and the "Boulevard Costanero" in Cabimas, a reduced population of fishermen was found (8 and 20 respectively). A nominal scale interview was used to collect data on the reason for fishing activity, capture period, fishing gear, and closed season. On Boulevard Costanero, commercial value is the main reason, followed by good flavor and a source of work, with notable catches in January-April. In contrast, in the Blue Lagoon Park, the reasons are divided equally, with captures throughout the year and exclusive use of pots. The creel is the predominant fishing gear in both locations, with differences in its distribution. The analysis of variance shows that the motive "Good taste" significantly influences the commercial value, while "Source of work" does not have a relevant impact. These results underline the importance of flavor in the commercial valuation of blue crab, without significant differences in the labor aspect.

Plants used by the Kariña tribe in Pueblo Nuevo from the Caris, Anzoátegui state, Venezuela.

2024-12-30T13:47:48+00:00

The plants used by the Kariña tribe in Pueblo Nuevo of Caris, Anzoátegui state, Venezuela, were inventoried. Ten useful plant species were determined, principally used in traditional medicine, according to the expertise of a native consultant who was familiarized with the local vegetation. Fabaceae was the family that presented the largest number of species (2). Among the most treated illness found were pain from bruises soreness or dental and join pain. The primary source of the botanical material encountered were six tree species, whereas the species most utilized part, was their bark and to a lesser extent the stem, root and fruits.

Instrucciones a los autores

2024-12-30T13:55:59+00:00

Instructions for Contributors

2024-12-30T14:00:19+00:00